Heparin prevents Zika virus induced-cytopathic effects in human neural progenitor cells

Abstract

The recent Zika virus (ZIKV) outbreak, which mainly affected Brazil and neighbouring states, demonstrated the paucity of information concerning the epidemiology of several flaviruses, but also highlighted the lack of available agents with which to treat such emerging diseases. Here, we show that heparin, a widely used anticoagulant, while exerting a modest inhibitory effect on Zika Virus replication, fully prevents virus-induced cell death of human neural progenitor cells (NPCs).

Keywords: Cell death; Heparin; Neural progenitor cells; Zika virus (ZIKV).

Fig. 1

Heparin does not inhibit ZIKV infection of hNPCs. A. Infection of hNPCs with the MR766 strain with (middle two panels) and without (upper two panels) heparin treatment (100 μg/ml). To determine that the cells were bona fide hNPCs, cells were stained with Sox2 (red), Nestin (green) and Hoechst (blue). Uninfected and infected cells were fixed after 3 days with paraformaldehyde solution and stained with a mAb specific for Flavivirus E protein (green). After PBS washes, cells were washed again, mounted and examined by microscopy. Quantification of infection efficiency and viral titers released into the culture supernatant are reported in the two lower panels (left and right, respectively). Scale bar of upper left panel: 20 μm, scale bar of remaining panels: 5 μm. Bar graphs indicate the mean ± SEM of 4 independent experiments. P values were calculated by Student's paired t-test. B. Infection of hNPCs by the INMI-1 strain, with (middle two panels) or without (upper panel) heparin treatment (100 μg/ml). Uninfected and infected cells were fixed after 7 days with paraformaldehyde solution and stained with a mAb specific for Flavivirus E protein (green). Quantification of infection efficiency and viral titers released into the culture supernatant are reported in the lower two panels (left and right, respectively). Scale bar: 5 μm. Bar graphs indicate the mean ± SEM of 2 fields including more than 1000 cells in 3 independent experiments. P values were calculated by Student's paired t-test. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 2

Heparin prevents virus-induced CPE. A. Supernatant of infected hNPCs with the MR766 strain was collected 3 days post infection. The results are expressed as relative luminescent unit (RLU). Data are expressed as mean ± SEM of 3 independent experiments. Repeated measures Anova was used with the Bonferroni correction. *Represents statistical comparison among groups (**, p < 0.01; *, p < 0.05). B. Supernatant of infected hNPCs with the INMI-1 strain was collected 7 days post infection. The cell death was analyzed as reported in A. Results are expressed as relative luminescent units (RLU). Data represent the mean ± SEM of 3 independent experiments. Repeated Measures ANOVA was used with the Bonferroni correction. *Represents statistical comparison among groups (**, p < 0.01; *, p < 0.05).