Zika virus infection induces mitosis abnormalities and apoptotic cell death of human neural progenitor cells.

Bruno S F Souza,Silvia I Sardi,Rosalia Mendez-Otero,Gabriela L A Sampaio,Bruno D Paredes,Milena B P Soares,Vinicius P C Rocha,Antonio C Bandeira,Carolina K V Nonaka,Ciro S Pereira,Gubio S Campos,Ricardo Ribeiro Dos Santos,Carine M Azevedo,Luiz A R Freitas,Claudio P Figueira

doi:10.1038/srep39775

Bruno S F Souza, Silvia I Sardi + Show 13 more

Open Access

https://doi.org/10.1038/srep39775

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Abstract

Zika virus (ZIKV) infection has been associated with severe complications both in the developing and adult nervous system. To investigate the deleterious effects of ZIKV infection, we used human neural progenitor cells (NPC), derived from induced pluripotent stem cells (iPSC). We found that NPC are highly susceptible to ZIKV and the infection results in cell death. ZIKV infection led to a marked reduction in cell proliferation, ultrastructural alterations and induction of autophagy. Induction of apoptosis of Sox2+ cells was demonstrated by activation of caspases 3/7, 8 and 9, and by ultrastructural and flow cytometry analyses. ZIKV-induced death of Sox2+ cells was prevented by incubation with the pan-caspase inhibitor, Z-VAD-FMK. By confocal microscopy analysis we found an increased number of cells with supernumerary centrosomes. Live imaging showed a significant increase in mitosis abnormalities, including multipolar spindle, chromosome laggards, micronuclei and death of progeny after cell division. FISH analysis for chromosomes 12 and 17 showed increased frequency of aneuploidy, such as monosomy, trisomy and polyploidy. Our study reinforces the link between ZIKV and abnormalities in the developing human brain, including microcephaly.

Highlights

Infection, relying on either type I interferon defective strains, direct injection on fetal cerebral ventricles or injection into the bloodstream of immunocompetent female pregnant mice at extraordinary high titers
We analyzed the expression of Doublecortin (DCX), a microtubule-associated protein expressed in migrating neuroblasts[20], in order to evaluate if Zika virus (ZIKV) infection would affect cells at a subsequent stage of neural differentiation
The results presented demonstrate that the Brazilian ZIKV strain is highly lethal to human neural stem/ progenitor cells, which express the transcription factor Sox[2]

Summary

Introduction

Infection, relying on either type I interferon defective strains, direct injection on fetal cerebral ventricles or injection into the bloodstream of immunocompetent female pregnant mice at extraordinary high titers. Experimental studies in neural developmental disorders have traditionally been complicated due to the difficulty in obtaining human neuronal cells. Human iPSCs can be stimulated to undergo neuronal specification and recapitulate several aspects of differentiation and maturation that occur in the normal embryo development. Centrosome alterations are closely linked to development of microcephaly, due to their role in cell division, and for their importance in the polarization of neural stem cells[16,17]. Cultures of iPSC-derived cells undergoing neural specification were infected with ZIKV isolated in Brazil during the 2015 outbreak. We show here that ZIKV causes massive death of neural stem cells, which is, at least in part, caused by cell division abnormalities, including the presence of supernumerary centrosomes. Our results reinforce the link between ZIKV infection and the reported defects in central nervous system development

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