Zika virus infection dysregulates human neural stem cell growth and inhibits differentiation into neuroprogenitor cells

Pradip Devhare,Keith Meyer,Ranjit Ray,Ratna B Ray,Robert Steele

doi:10.1038/cddis.2017.517

Abstract

The current outbreak of Zika virus-associated diseases in South America and its threat to spread to other parts of the world has emerged as a global health emergency. A strong link between Zika virus and microcephaly exists, and the potential mechanisms associated with microcephaly are under intense investigation. In this study, we evaluated the effect of Zika virus infection of Asian and African lineages (PRVABC59 and MR766) in human neural stem cells (hNSCs). These two Zika virus strains displayed distinct infection pattern and growth rates in hNSCs. Zika virus MR766 strain increased serine 139 phosphorylation of histone H2AX (γH2AX), a known early cellular response proteins to DNA damage. On the other hand, PRVABC59 strain upregulated serine 15 phosphorylation of p53, p21 and PUMA expression. MR766-infected cells displayed poly (ADP-ribose) polymerase (PARP) and caspase-3 cleavage. Interestingly, infection of hNSCs by both strains of Zika virus for 24 h, followed by incubation in astrocyte differentiation medium, induced rounding and cell death. However, astrocytes generated from hNSCs by incubation in differentiation medium when infected with Zika virus displayed minimal cytopathic effect at an early time point. Infected hNSCs incubated in astrocyte differentiating medium displayed PARP cleavage within 24–36 h. Together, these results showed that two distinct strains of Zika virus potentiate hNSC growth inhibition by different mechanisms, but both viruses strongly induce death in early differentiating neuroprogenitor cells even at a very low multiplicity of infection. Our observations demonstrate further mechanistic insights for impaired neuronal homeostasis during active Zika virus infection.

Highlights

Zika virus infection and its association with microcephaly and Guillain–Barré syndrome have created an urgency to understand the disease mechanisms.[1,2] The probability of fetal microcephaly in Zika virus-infected pregnant women ranges from 1 to 13%
Vero cells infected with PRVABC59 and MR766 displayed a similar pattern of immunofluorescence for the E glycoprotein, which is localized in the perinuclear and nuclear region
HNSCs infected with PRVABC59 displayed localization of E glycoprotein as perinuclear punctate dots, whereas MR766 E glycoprotein displayed a similar pattern of localization as observed in Vero cells

Summary

Introduction

Zika virus infection and its association with microcephaly and Guillain–Barré syndrome have created an urgency to understand the disease mechanisms.[1,2] The probability of fetal microcephaly in Zika virus-infected pregnant women ranges from 1 to 13%. The adult mammalian brain contains self-renewable, multipotent neural stem cells (NSCs) that are responsible for neurogenesis and plasticity.[11,12,13,14,15] Extracellular matrix, vasculature, glial cells and other neurons are components of the niche where NSCs are located. This surrounding environment is the source of extrinsic signals that instruct NSCs to either self-renew or differentiate.[16] NSCs give rise to neurons, astrocytes and oligodendrocytes. A cellular RNA binding protein Musashi-1 (MSI1) has been shown to support Zika virus replication.[22,23] The developmental stage of neural progenitor cells is a determinant of the level of MSI1expression and neural progenitor cells are most susceptible to Zika virus when immature

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Conclusion