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. 2022 Jun 30:13:903860.
doi: 10.3389/fimmu.2022.903860. eCollection 2022.

Zika Virus Induces Sex-Dependent Metabolic Changes in Drosophila melanogaster to Promote Viral Replication

Affiliations

Zika Virus Induces Sex-Dependent Metabolic Changes in Drosophila melanogaster to Promote Viral Replication

Ghada Tafesh-Edwards et al. Front Immunol. .

Abstract

Zika is a member of the Flaviviridae virus family that poses some of the most significant global health risks, causing neurologic complications that range from sensory neuropathy and seizures to congenital Zika syndrome (microcephaly) in infants born to mothers infected during pregnancy. The recent outbreak of Zika virus (ZIKV) and its serious health threats calls for the characterization and understanding of Zika pathogenesis, as well as host antiviral immune functions. Although ZIKV has been associated with activating the RNA interference (RNAi) immune pathway and altering host metabolism, in-depth studies are still required to uncover the specifics of the complex host-virus interactions and provide additional insights into the molecular components that determine the outcome of this disease. Previous research establishes the fruit fly Drosophila melanogaster as a reliable model for studying viral pathogens, as it shares significant similarities with that of vertebrate animal systems. Here, we have developed an in vivo Drosophila model to investigate ZIKV-mediated perturbed metabolism in correlation to the RNAi central mediator Dicer-2. We report that ZIKV infection reprograms glucose and glycogen metabolism in Dicer-2 mutants to maintain efficient replication and successful propagation. Flies that exhibit these metabolic effects also show reduced food intake, which highlights the complicated neurological defects associated with ZIKV. We show that ZIKV infection significantly reduces insulin gene expression in Dicer-2 mutants, suggesting an insulin antiviral role against ZIKV and a direct connection to RNAi immunity. Moreover, we find that the insulin receptor substrate chico is crucial to the survival of ZIKV-infected flies. These observations are remarkably more severe in adult female flies compared to males, indicating possible sex differences in the rates of infection and susceptibility to the development of disease. Such findings not only demonstrate that metabolic alterations can be potentially exploited for developing immune therapeutic strategies but also that preventive measures for disease development may require sex-specific approaches. Therefore, further studies are urgently needed to explore the molecular factors that could be considered as targets to inhibit ZIKV manipulation of host cell metabolism in females and males.

Keywords: Drosophila; RNA interference; Zika virus; innate immunity; metabolism.

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Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

Figure 1
Figure 1
Feeding rate of Drosophila melanogaster upon infection with Zika virus. (A) Drosophila female and male adult Dicer-2 mutants and their background controls (YW) were injected with ZIKV (African strain MR766; 110 million PFUs/ml), and feeding was estimated at 4 days post infection. Injections with PBS served as negative controls. (B) Dye-stained food in the abdomen of ZIKV-injected or PBS-injected Dicer-2 mutants and YW individuals. Data represent three biological replicates of at least 20 flies for each experimental condition. (One-way ANOVA, ****p < 0.0001).
Figure 2
Figure 2
Carbohydrate metabolism in Drosophila melanogaster 4 days after infection with Zika virus (ZIKV). (A, B) Glucose levels in infected female and male Dicer-2 mutant adults compared to YW (background line) and PBS (no infection treatment) controls. (C, D) Trehalose levels in ZIKV-infected and PBS-injected Dicer-2 mutants and YW flies. (E, F) Glycogen levels in ZIKV-infected and PBS-injected Dicer-2 mutants and their YW background controls. All experiments were performed in duplicates and repeated three times. (One-way ANOVA, *p < 0.01, **p < 0.001, ***p < 0.0001).
Figure 3
Figure 3
Cholesterol levels in Drosophila melanogaster Dicer-2 mutant adult flies and their YW background controls infected with Zika virus (ZIKV) or injected with PBS (uninfected controls). Quantification experiments were performed in biological duplicates and repeated three times using female (A) and male (B) individuals. (One-way ANOVA).
Figure 4
Figure 4
Analysis of insulin-regulated gene expression through quantitative RT-PCR in Zika virus (ZIKV)-infected Drosophila melanogaster Dicer-2 mutants and YW background control flies compared to uninfected (PBS-injected) background controls. Levels of mRNA were normalized against RpL32 (housekeeping gene), and three independent experiments were performed using adult females (A) and males (B). (Two-way ANOVA, *p = 0.0252, **p = 0.0018, ***p = 0.0009, ****p < 0.0001).
Figure 5
Figure 5
Survival of Drosophila melanogaster adult flies after intrathoracic injection with Zika virus (ZIKV) was monitored at 24-h intervals for 35 days. Injections with PBS served as negative controls. (A, B) Survival of FOXO female and male mutants compared to their background (w1118 ) controls. (C, D) Survival of Chico female and male mutants compared to YW background controls. Data represent three biological replicates of at least 20 adult flies. Log-rank (Mantel–Cox) was used for statistical analysis, **p = 0.0033, ***p = 0.0001, ****p < 0.0001.
Figure 6
Figure 6
Zika virus (ZIKV) load using qRT-PCR analysis and NS5 gene-specific primers in Drosophila melanogaster Foxo and Chico mutants compared to their background controls YW and w1118 , respectively. Data, collected from female (A, B) and male (C, D) adult flies, were normalized to the housekeeping gene RpL32 shown relative to control flies injected with PBS (injury control). Three independent experiments were carried out with 10 flies per sample in technical duplicates (One-way ANOVA, *p < 0.01, **p < 0.001).
Figure 7
Figure 7
RNAi signaling activity in Zika virus (ZIKV)-infected Drosophila melanogaster insulin mutants. Mutant adult flies for Foxo and Chico were processed for RNA analysis and gene expression levels were determined by qRT-PCR at 4 days post infection. Transcript levels of the RNAi genes Dicer-2 and Ago-2 in females (A, B) and males (C, D) are shown (Two-way ANOVA, *p = 0.0272, **p < 0.001, ***p = 0.0005).

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References

    1. Sasi MS, Rajendran R, Meenakshy V, Suresh T, Heera Pillai R, Dilip Kumar T, et al. . Study on Vector Dynamics of Zika Virus Outbreak in Thiruvananthapuram, Kerala, India. Int J Curr Microbiol App Sci (2021) 10:54–71. doi: 10.20546/ijcmas.2021.1012.008 - DOI
    1. Zhang X, Li G, Chen G, Zhu N, Wu D, Wu Y, et al. . Recent Progresses and Remaining Challenges for the Detection of Zika Virus. Med Res Rev (2021) 41:2039–108. doi: 10.1002/med.21786 - DOI - PubMed
    1. Martins MM, Alves da Cunha AJL, Robaina JR, Raymundo CE, Barbosa AP, Medronho RA. Fetal, Neonatal, and Infant Outcomes Associated With Maternal Zika Virus Infection During Pregnancy: A Systematic Review and Meta-Analysis. PLoS One (2021) 16:e0246643. doi: 10.1371/journal.pone.0246643 - DOI - PMC - PubMed
    1. Martins MM, Medronho RA, Cunha AJLAD. Zika Virus in Brazil and Worldwide: A Narrative Review. Paediatr Int Child Health (2021) 41:28–35. doi: 10.1080/20469047.2020.1776044 - DOI - PubMed
    1. Espinal MA, Andrus JK, Jauregui B, Waterman SH, Morens DM, Santos JI, et al. . Emerging and Reemerging Aedes-Transmitted Arbovirus Infections in the Region of the Americas: Implications for Health Policy. Am J Public Health (2019) 109:387–92. doi: 10.2105/AJPH.2018.304849 - DOI - PMC - PubMed

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