Zika Research Articles

Insight into the Natural Biomolecules (BMs): Promising Candidates as Zika Virus Inhibitors.

Zika virus (ZIKV) is among the relatively new infectious disease threats that include SARS-CoV-2, coronavirus, monkeypox (Mpox) virus, etc. ZIKV has been reported to cause severe health risks to the fetus. To date, satisfactory treatment is still not available for the treatment of ZIKV infection. This review examines the last five years of work using natural biomolecules (BMs) to counteract the ZIKV through virtual screening and in vitro investigations. Virtual screening has identified doramectin, pinocembrin, hesperidins, epigallocatechin gallate, pedalitin, and quercetin as potentially active versus ZIKV infection. In vitro, testing has shown that nordihydroguaiaretic acid, mefloquine, isoquercitrin, glycyrrhetinic acid, patentiflorin-A, rottlerin, and harringtonine can reduce ZIKV infections in cell lines. However, in vivo, testing is limited, fortunately, emetine, rottlerin, patentiflorin-A, and lycorine have shown in vivo anti- ZIKV potential. This review focuses on natural biomolecules that show a particularly high selective index (>10). There is limited in vivo and clinical trial data for natural BMs, which needs to be an active area of investigation. This review aims to compile the known reference data and discuss the barriers associated with discovering and using natural BM agents to control ZIKV infection.

RNA-Seq Reveals Transcriptome Changes Following Zika Virus Infection in Fetal Brains in c-Flip Knockdown Mice

The FADD-like interleukin-1β converting enzyme (FLICE)-inhibitory protein (c-FLIP) plays a crucial role in various biological processes, including apoptosis and inflammation. However, the complete transcriptional profile altered by the c-FLIP is not fully understood. Furthermore, the impact of the c-FLIP deficiency on the transcriptome during a Zika virus (ZIKV) infection, which induces apoptosis and inflammation in the central nervous system (CNS), has not yet been elucidated. In this study, we compared transcriptome profiles between wild-type (WT) and the c-Flip heterozygous knockout mice (c-Flip+/−) fetal heads at embryonic day 13.5 from control and PBS-infected WT dams mated with c-Flip+/− sires. In the non-infected group, we observed differentially expressed genes (DEGs) mainly involved in embryonic development and neuron development. However, the ZIKV infection significantly altered the transcriptional profile between WT and the c-Flip+/− fetal heads. DEGs in pattern recognition receptor (PRR)-related signaling pathways, such as the RIG-I-like receptor signaling pathway and Toll-like receptor signaling pathway, were enriched. Moreover, the DEGs were also enriched in T cells, indicating that the c-FLIP participates in both innate and adaptive immune responses upon viral infection. Furthermore, our observations indicate that DEGs are associated with sensory organ development and eye development, suggesting a potential role for the c-FLIP in ZIKV-induced organ development defects. Overall, we have provided a comprehensive transcriptional profile for the c-FLIP and its modulation during a ZIKV infection.

Using models and maps to inform Target Product Profiles and Preferred Product Characteristics: the example of Wolbachia replacement

Background The global prevalence of diseases transmitted by Aedes aegypti mosquitoes, such as dengue, Zika and Yellow Fever, is increasing, but development of promising new mosquito control technologies could reverse this trend. Target Product Profiles (TPPs) and Preferred Product Characteristics (PPCs) documents issued by the World Health Organization can guide the research and development pathways of new products and product combinations transitioning from proof of concept to operational use. Methods We used high resolution global maps of the case and economic burden of dengue to derive programmatic cost targets to support a TPP for Wolbachia replacement. A compartmental entomological model was used to explore how release size, spacing and timing affect replacement speed and acceptability. To support a PPC for a hybrid suppress-then-replace approach we tested whether Wolbachia replacement could be achieved faster, more acceptably or at a lower cost if preceded by a mosquito suppression programme. Results We show how models can reveal trade-offs, identify quantitative thresholds and prioritise areas and intervention strategies for further development. We estimate that for Wolbachia replacement to be deployable in enough areas to make major contributions to reducing global dengue burden by 25% (in line with 2030 WHO targets), it must have the potential for cost to be reduced to between $7.63 and $0.24 (USD) per person protected or less. Suppression can reduce the number of Wolbachia mosquitoes necessary to achieve replacement fixation by up to 80%. A hybrid approach can also achieve fixation faster and potentially improve acceptability, but may not justify their cost if they require major new investments in suppression technologies. Conclusions Here we demonstrate the value dedicated modelling can provide for interdisciplinary groups of experts when developing TPPs and PPCs. These models could be used by product developers to prioritise and shape development decisions for new Wolbachia replacement products.

Erp57 facilitates ZIKV-induced DNA damage via NS2B/NS3 complex formation.

It is believed that DNA double-strand breaks induced by Zika virus (ZIKV) infection in pregnant women is a main reason of brain damage (e.g. microcephaly, severe brain malformation, and neuropathy) in newborn babies [1,2], but its underlying mechanism is poorly understood. In this study, we report that the depletion of ERp57, a member of the protein disulphide isomerase (PDI) family, leads to the limited production of ZIKV in nerve cells. ERp57 knockout not only suppresses viral induced reactive oxygen species (ROS) mediated host DNA damage, but also decreases apoptosis. Strikingly, DNA damage depends on ERp57-bridged complex formation of viral protein NS2B/NS3. LOC14, an ERp57 inhibitor, restricts ZIKV infection and virus-induced DNA damage. Our work reveals an important role of ERp57 in both ZIKV propagation and virus-induced DNA damage, suggesting a potential target against ZIKV infection.

DENV and ZIKV infection: Species specificity and broad cell tropism

Nearly one-third of countries worldwide have reported cases of Dengue virus (DENV) and Zika virus (ZIKV) infections, highlighting the significant threat these viruses pose to global public health. As members of the Flavivirus genus within the Flaviviridae family, DENV and ZIKV have demonstrated the ability to infect a wide range of cell lines from multiple species in vitro. However, the range of susceptible animal models is notably limited, and field studies indicate that their capacity to infect host organisms is highly restricted, with a very narrow range of target cells in vivo. The virus's ability to hijack host cellular machinery plays a crucial role in determining its cellular and species specificity. In this review, we examine how DENV and ZIKV exploit host cells to facilitate their replication, offering new insights that could inform the development of antiviral drugs and therapeutic targets.

Biological Control of Aedes aegypti Larvae using Sea Shell Powder

Background: The Aedes aegypti mosquito is a primary vector for several arboviral diseases, including dengue, Zika, chikungunya and yellow fever, posing significant public health challenges, especially in tropical and subtropical regions. Traditional chemical insecticides have been the mainstay for controlling Aedes aegypti populations, but their extensive use has led to the development of insecticide resistance, environmental pollution and adverse effects on non-target organisms. This study explores the potential of sea shell powder as a natural larvicide against Aedes aegypti larvae. Methods: Sea shell powder, derived from the calcified exoskeletons of marine mollusks, was tested for its larvicidal activity against fourth instar larvae of Ae. aegypti at concentrations ranging from 100 to 600 ppm. Result: The results demonstrated a concentration and time-dependent increase in larval mortality, with LC50 values of 407.01 ppm at 24 hours and 327.55 ppm at 48 hours. The findings suggest that sea shell powder could serve as an effective, environmentally sustainable alternative to chemical insecticides, offering advantages such as biodegradability, low cost and reduced risk of resistance development. This study supports the potential inclusion of sea shell powder in integrated mosquito management programs, particularly in areas with prevalent insecticide resistance.

Activation of ATF3 via the integrated stress response pathway regulates innate immune response to restrict Zika virus.

Zika virus (ZIKV) is a re-emerging mosquito-borne flavivirus that co-opts cellular mechanisms to support viral processes that can reprogram the host transcriptional profile. Such viral-directed transcriptional changes and the pro- or anti-viral outcomes remain understudied. We previously showed that ATF3, a stress-induced transcription factor, is significantly upregulated in ZIKV-infected mammalian cells, along with other cellular and immune response genes. We now define the intracellular pathway responsible for ATF3 activation and elucidate the impact of ATF3 expression on ZIKV infection. We show that during ZIKV infection, the integrated stress response pathway stimulates ATF3 which enhances the innate immune response to antagonize ZIKV infection. This study establishes a link between viral-induced stress response and transcriptional regulation of host defense pathways and thus expands our knowledge of virus-mediated transcriptional mechanisms and transcriptional control of interferon-stimulated genes during ZIKV infection.

Systematic Review on Citizen Science and Artificial Intelligence for Vector-Borne Diseases

Abstract. Vector-borne diseases (VBDs) pose a significant threat to public health globally. VBDs are a significant public health concern worldwide, with infections such as Malaria, Dengue Fever, Zika Virus, and Lyme Disease posing a threat to global health security. There is a need for innovative and effective strategies to control these diseases. One potential solution lies in the integration of citizen science and artificial intelligence technologies. Citizen science, which involves the participation of volunteers in scientific research, can greatly contribute to data collection and monitoring efforts for vector-borne diseases. Artificial intelligence can enhance the analysis of this data, leading to improved disease surveillance, prediction, and control strategies. Citizen Science involves active public participation in scientific research, data collection, and analysis, while AI and Machine Learning (ML) techniques offer powerful tools for processing and interpreting large datasets. By leveraging the power of citizen science and artificial intelligence, we can harness the collective efforts of volunteers and advanced technology to better understand, track, and mitigate the spread of vector-borne diseases. Through the combination of citizen science and artificial intelligence, a more comprehensive and efficient approach can be taken to gather data on vector-borne diseases, analyze the data, and inform public health interventions. This systematic review aims to explore the role of citizen science and artificial intelligence in addressing the challenges associated with vector-borne diseases. It will examine the existing literature on the use of citizen science and artificial intelligence in vector-borne disease research, including their applications, benefits, and limitations, in order to provide insights and recommendations for future research and public health strategies.

Zika virus T-cell based 704/DNA vaccine promotes protection from Zika virus infection in the absence of neutralizing antibodies.

Zika virus (ZIKV) and dengue virus (DENV) are closely related flaviviruses co-circulating in the same endemic areas. Infection can raise cross-reactive antibodies that can be either protective or increase risk of severe disease, depending on the infection sequence, DENV serotype and elapsed time between infection. On the contrast, T cell-mediated immunity against DENV and ZIKV is considered protective. Therefore, we have developed a T cell vaccine enriched in immunodominant T cell epitopes derived from ZIKV and evaluated its immunogenicity and efficacy against ZIKV and DENV infection. Mice were vaccinated using DNA vaccine platform using the tetrafunctional amphiphilic block copolymer 704. We show that vaccination of 2 different HLA class I transgenic mice with the ZIKV non-structural (NS) poly-epitope elicits T cell response against numerous ZIKV epitopes. Moreover, vaccination induces a significant protection against ZIKV infection, in the absence of neutralizing or enhancing antibodies against ZIKV. However, vaccination does not induce a significant protection against DENV2. In contrast, immunization with a DENV1-NS poly-epitope induces a significant protection against both DENV1 and DENV2, in the absence of humoral immunity. Taken together, we have shown that T-cell based vaccination could protect against multiple flavivirus infections and could overcome the complexity of antibody-mediated enhancement.

A single-dose circular RNA vaccine prevents Zika virus infection without enhancing dengue severity in mice

Antibody-dependent enhancement (ADE) is a potential concern for the development of Zika virus (ZIKV) vaccines. Cross-reactive but poorly neutralizing antibodies, usually targeting viral pre-membrane or envelope (E) proteins, can potentially enhance dengue virus (DENV) infection. Although E domain III (EDIII) contains ZIKV-specific epitopes, its immunogenicity is poor. Here, we show that dimeric EDIII, fused to human IgG1 Fc fragment (EDIII-Fc) and encoded by circular RNA (circRNA), induces better germinal center reactions and higher neutralizing antibodies compared to circRNAs encoding monomeric or trimeric EDIII. Two doses of circRNAs encoding EDIII-Fc and ZIKV nonstructural protein NS1, another protective antigen, prevent lethal ZIKV infection in neonates born to immunized C57BL/6 mice and in interferon-α/β receptor knockout adult C57BL/6 mice. Importantly, a single-dose optimized circRNA vaccine with improved antigen expression confers potent and durable protection without inducing obvious DENV ADE in mice, laying the groundwork for developing flavivirus vaccines based on circRNAs encoding EDIII-Fc and NS1.

Evidence of Natural Zika Virus Infection in Captive Cervid Species in Brazil.

As part of an epidemiologic study of the Zika virus (ZIKV) in deer (Cervidae), samples from 56 captive deer in south and southeastern Brazil were tested for evidence of ZIKV. Three samples were positive using reverse-transcription quantitative PCR, although no samples were positive by virus isolation.

A Narrative Review on the Pandemic Zoonotic RNA Virus Infections Occurred During the Last 25 Years.

Pandemic zoonotic RNA virus infections have continued to threaten humans and animals worldwide. The objective of this review was to highlight the epidemiology and socioeconomic impacts of pandemic zoonotic RNA virus infections that occurred between 1997 and 2021. Literature search was done from Web of Science, PubMed, Google Scholar and Scopus databases, cumulative case fatalities of individual viral infection calculated, and geographic coverage of the pandemics were shown by maps. Seven major pandemic zoonotic RNA virus infections occurred from 1997 to 2021 and were presented in three groups: The first group consists of highly pathogenic avian influenza (HPAI-H5N1) and swine-origin influenza (H1N1) viruses with cumulative fatality rates of 53.5% and 0.5% in humans, respectively. Moreover, HPAI-H5N1 infection caused 90-100% death in poultry and economic losses of >$10billion worldwide. Similarly, H1N1 caused a serious infection in swine and economic losses of 0.5-1.5% of the Gross Domestic Product (GDP) of the affected countries. The second group consists of severe acute respiratory syndrome-associated coronavirus infection (SARS-CoV), Middle East Respiratory Syndrome (MERS-CoV) and Coronavirus disease 2019 (COVID-19) with case fatalities of 9.6%, 34.3% and 2.0%, respectively in humans; but this group only caused mild infections in animals. The third group consists of Ebola and Zika virus infections with case fatalities of 39.5% and 0.02%, respectively in humans but causing only mild infections in animals. Similar infections are expected in the near future, and hence strict implementation of conventional biosecurity-based measures and development of efficacious vaccines would help minimize the impacts of the next pandemic infection.

8624 Maternal ZIKV Infection Causes Oxidative Damage in Placenta of Both Female and Male Mice

Abstract Disclosure: V.M. Nascimento: None. I.S. Andrade: None. C.B. Andrade: None. R.S. Alves: None. R.P. Sousa: None. A.C. Valim: None. L.S. Dias: None. K.N. Fontes: None. I.F. Miranda: None. S.A. Coelho: None. L.B. Arruda: None. R.S. Fortunato: None. T.M. Ortiga-Carvalho: None. The placenta is a maternal-fetal organ with nutritional, exchanging, hormonal and protecting functions that are vital for fetal growth and development during gestation. However, these functions can be disturbed by vertically transmitted pathogens such as Zika virus (ZIKV). In 2015, ZIKV was responsible for an increasing number of newborns with congenital abnormalities in Brazil, known as Congenital Zika Syndrome (CZS). Nonetheless, the extension of ZIKV infection in the placenta, leading to CZS, is still unclear. It is known that ZIKV causes oxidative stress in trophoblasts. However, no one has ever studied placental oxidative stress caused by ZIKV infection in vivo. Here, we investigated whether maternal ZIKV infection could cause sex-specific oxidative stress in murine placenta. At gestational day (GD)12.5, pregnant mice (C57BL/6; 8-12 weeks old) were infected with ZIKV-BRPE243 (5x107 PFU; ZIKV group, n=22) or Mock (supernatants of noninfected C6/36 cells; control group, n=28). At GD18.5, c-section was performed and maternal spleens, placentas, fetuses and fetal brains were collected. We measured placental carbonylated protein levels (n=7), by 2D OxyBlot, nitrotyrosine residues (n=5), by immunohistochemistry, reduced thiol content (n=9), total superoxide dismutase (SOD; n=9) and total glutathione peroxidase (GPx; n=9) activities, by spectrophotometry. Data were analyzed by unpaired Student’s t test and Two-Way ANOVA with Tukey’s post test and represented as mean±SEM. ZIKV infection increased maternal spleen weight (p<0.0001) and decreased both female (p=0.0429) and male (p=0.0171) placental weight. Although placental weights were affected by the infection, female and male fetal weight and fetal crown-rump length were not changed. Conversely, maternal ZIKV infection increased only female fetal brain weight (p=0.0028). Moreover, we found that ZIKV infection increased nitrotyrosine residues in the placental labyrinth region of both female (p<0.0001) and male (p=0.0007) fetuses. Meanwhile, nitrotyrosine residues were increased by the infection only in the placental junctional zone of female fetuses (p=0.0131). Although ZIKV increased this oxidative damage biomarker, placental carbonylated protein levels were not changed by the infection in both sexes. Also, reduced thiol content and total SOD and GPx activities were not affected. Together, our data show that maternal ZIKV infection caused oxidative stress in both placental regions of female and male fetuses, as we saw that ZIKV increased oxidative damage, although antioxidant defenses were not changed by the infection, at least at term (GD18.5). ZIKV infection may have disturbed placental growth, as we found that placental weight was decreased in both sexes. Moreover, we believe that the increase in the female fetal brain weight could be a suggestive feature of cerebral edema or hydrocephalus. Presentation: 6/2/2024

8624 Maternal ZIKV Infection Causes Oxidative Damage in Placenta of Both Female and Male Mice

Abstract Disclosure: V.M. Nascimento: None. I.S. Andrade: None. C.B. Andrade: None. R.S. Alves: None. R.P. Sousa: None. A.C. Valim: None. L.S. Dias: None. K.N. Fontes: None. I.F. Miranda: None. S.A. Coelho: None. L.B. Arruda: None. R.S. Fortunato: None. T.M. Ortiga-Carvalho: None. The placenta is a maternal-fetal organ with nutritional, exchanging, hormonal and protecting functions that are vital for fetal growth and development during gestation. However, these functions can be disturbed by vertically transmitted pathogens such as Zika virus (ZIKV). In 2015, ZIKV was responsible for an increasing number of newborns with congenital abnormalities in Brazil, known as Congenital Zika Syndrome (CZS). Nonetheless, the extension of ZIKV infection in the placenta, leading to CZS, is still unclear. It is known that ZIKV causes oxidative stress in trophoblasts. However, no one has ever studied placental oxidative stress caused by ZIKV infection in vivo. Here, we investigated whether maternal ZIKV infection could cause sex-specific oxidative stress in murine placenta. At gestational day (GD)12.5, pregnant mice (C57BL/6; 8-12 weeks old) were infected with ZIKV-BRPE243 (5x107 PFU; ZIKV group, n=22) or Mock (supernatants of noninfected C6/36 cells; control group, n=28). At GD18.5, c-section was performed and maternal spleens, placentas, fetuses and fetal brains were collected. We measured placental carbonylated protein levels (n=7), by 2D OxyBlot, nitrotyrosine residues (n=5), by immunohistochemistry, reduced thiol content (n=9), total superoxide dismutase (SOD; n=9) and total glutathione peroxidase (GPx; n=9) activities, by spectrophotometry. Data were analyzed by unpaired Student’s t test and Two-Way ANOVA with Tukey’s post test and represented as mean±SEM. ZIKV infection increased maternal spleen weight (p<0.0001) and decreased both female (p=0.0429) and male (p=0.0171) placental weight. Although placental weights were affected by the infection, female and male fetal weight and fetal crown-rump length were not changed. Conversely, maternal ZIKV infection increased only female fetal brain weight (p=0.0028). Moreover, we found that ZIKV infection increased nitrotyrosine residues in the placental labyrinth region of both female (p<0.0001) and male (p=0.0007) fetuses. Meanwhile, nitrotyrosine residues were increased by the infection only in the placental junctional zone of female fetuses (p=0.0131). Although ZIKV increased this oxidative damage biomarker, placental carbonylated protein levels were not changed by the infection in both sexes. Also, reduced thiol content and total SOD and GPx activities were not affected. Together, our data show that maternal ZIKV infection caused oxidative stress in both placental regions of female and male fetuses, as we saw that ZIKV increased oxidative damage, although antioxidant defenses were not changed by the infection, at least at term (GD18.5). ZIKV infection may have disturbed placental growth, as we found that placental weight was decreased in both sexes. Moreover, we believe that the increase in the female fetal brain weight could be a suggestive feature of cerebral edema or hydrocephalus. Presentation: 6/2/2024

Protein kinase R induced by type I interferons is a main regulator of reactive microglia in Zika virus infection.

Microglial cells are the phagocytic cells of the brain that under physiological conditions participate in brain homeostasis and surveillance. Under pathogenic states, microglia undergoes strong morphological and transcriptional changes potentially leading to sustained neuroinflammation, brain damage, and cognitive disorders. Postnatal and adult Zika virus (ZIKV) brain infection is characterized by the induction of reactive microglia associated with brain inflammation, synapse loss and neuropathogenesis. Contrary to neurons, microglial cells are not infected by ZIKV thus raising the question of the mechanism governing ZIKV-induced microglia's reactivity. In this work, we have questioned the role of exogenous, neuronal type I interferons (IFNs-I) in regulating ZIKV-induced microglia's reactivity. Primary cultured microglial cells were either treated with conditioned media from ZIKV-infected mature neurons or co-cultured with ZIKV-infected neurons. Using either an antibody directed against the IFNAR receptor that neutralizes the IFNs-I response or Ifnar-/-microglial cells, we demonstrate that IFNs-I produced by ZIKV-infected neurons are the main regulators of the phagocytic capacity and the pro-inflammatory gene expression profile of reactive, non-infected microglial cells. We identify protein kinase R (PKR), whose expression is activated by IFNs-I, as a major regulator of the phagocytic capacity, pro-inflammatory response, and morphological changes of microglia induced by IFNs-I while up-regulating STAT1 phosphorylation and IRF1 expression. Results obtained herein in vitro with primary cultured cells and in vivo in ZIKV-infected adult immunocompetent mice, unravel a role for IFNs-I and PKR in directly regulating microglia's reactivity that could be at work in other infectious and non-infectious brain pathologies.

Saxitoxin potentiates human neuronal cell death induced by Zika virus while sparing neural progenitors and astrocytes

The Zika virus (ZIKV) epidemic declared in Brazil between 2015 and 2016 was associated with an increased prevalence of severe congenital malformations, including microcephaly. The distribution of microcephaly cases was not uniform across the country, with a disproportionately higher incidence in the Northeast region (NE). Our previous work demonstrated that saxitoxin (STX), a toxin present in the drinking water reservoirs of the NE, exacerbated the damaging effects of ZIKV on the developing brain. We hypothesized that the impact of STX might vary among different neural cell types. While ZIKV infection caused severe damages on astrocytes and neural stem cells (NSCs), the addition of STX did not exacerbate these effects. We observed that neurons subjected to STX exposure were more prone to apoptosis and displayed higher ZIKV infection rate. These findings suggest that STX exacerbates the harmful effects of ZIKV on neurons, thereby providing a plausible explanation for the heightened severity of ZIKV-induced congenital malformations observed in Brazil’s NE. This study highlights the importance of understanding the interactive effects of environmental toxins and infectious pathogens on neural development, with potential implications for public health policies.

Coumarin-imidazopyridine hybrids and their first-in-class ZnII metal complexes as potent dual entry and replication inhibitors of Zika viral infection

In this study, we synthesized and characterized a series of coumarin-imidazopyridine hybrid ligands (HL1-HL4) and their corresponding Zn(II) complexes (C1-C4). The ligands were synthesized via a two-step process in 56–90 % yields. The resulting ligands, were utilized to form Zn(II) complexes, characterized by conductivity measurements, HRMS, IR, 1H NMR spectroscopy and X-ray diffractions. Biological evaluations revealed that these compounds exhibited potent antiviral activity against Zika virus (ZIKV), with EC50 values ranging from 0.55 to 4.8 µM and SI of up to 1490. Notably, the complexes (the first-in-class Zn(II) anti-ZIKV complexes) generally displayed enhanced activity compared to their respective ligands, with some compounds outperforming the reference antiviral, ribavirin. The Time of Addition assay suggested that while some compounds interfere with both viral entry (with a virucidal component) and replication phases, other only acted in replication phases. These results together with molecular modeling studies on ZIKV Envelope protein and ZIKV NS2B-NS3 offered insights for their mode of actions and further optimizations.

The Human Neural Cell Atlas of Zika Infection in developing human brain tissue: viral pathogenesis, innate immunity, and lineage reprogramming.

Zika virus (ZIKV) infection during pregnancy can lead to fetal brain infection and developmental anomalies collectively known as congenital Zika syndrome (CZS). To define the molecular features underlying CZS in a relevant human cell model, we evaluated ZIKV infection and neurodevelopment in primary fetal brain explants and induced pluripotent stem cell-derived mixed neural cultures at single cell resolution. We identified astrocytes as key innate immune sentinel cells detecting ZIKV and producing IFN-β. In contrast, neural progenitor cells displayed impaired innate immunity and supported high levels of viral replication. ZIKV infection of neurons suppressed differentiation and synaptic signaling networks and programmed a molecular switch from neurogenesis to astrogliogenesis. We identified a universal ZIKV-driven cellular stress response linked to intrinsic apoptosis and regulated by IFN-β. These findings reveal how innate immune signaling intersects with ZIKV-driven perturbations in cellular function to influence CZS outcomes including neuron developmental dysfunction and apoptotic cell death.

Prenatal Exposure to Herbicide 2,4-Dichlorophenoxyacetic Acid (2,4D) Exacerbates Zika Virus Neurotoxicity In Vitro and In Vivo.

Zika virus (ZIKV) infection during pregnancy can lead to a set of congenital malformations known as Congenital ZIKV syndrome (CZS), whose main feature is microcephaly. The geographic distribution of CZS in Brazil during the 2015-2017 outbreak was asymmetrical, with a higher prevalence in the Northeast and Central-West regions of the country, despite the ubiquitous distribution of the vector Aedes aegypti, indicating that environmental factors could influence ZIKV vertical transmission and/or severity. Here we investigate the involvement of the most used agrochemicals in Brazil with CZS. First, we exposed human neuroblastoma SK-N-AS cells to the 15 frequently used agrochemical molecules or derivative metabolites able to cross the blood-brain barrier. We found that a derived metabolite from a widely used herbicide in the Central-West region, 2,4-dichlorophenoxyacetic acid (2,4D), exacerbates ZIKV neurotoxic effects in vitro. We validate this observation by demonstrating vertical transmission leading to microcephaly in the offspring of immunocompetent C57BL/6J mice exposed to water contaminated with 0.025 mg/L of 2,4D. Newborn mice whose dams were exposed to 2,4D and infected with ZIKV presented a smaller brain area and cortical plate size compared to the control. Also, embryos from animals facing the co-insult of ZIKV and 2,4D exposition presented higher Caspase 3 positive cells in the cortex, fewer CTIP2+ neurons and proliferative cells at the ventricular zone, and a higher viral load. This phenotype is followed by placental alterations, such as vessel congestion, and apoptosis in the labyrinth and decidua. We also observed a mild spatial correlation between CZS prevalence and 2,4D use in Brazil's North and Central-West regions, with R2 = 0.4 and 0.46, respectively. Our results suggest that 2,4D exposition facilitates maternal vertical transmission of ZIKV, exacerbating CZS, possibly contributing to the high prevalence of this syndrome in Brazil's Central-West region compared to other regions.

Global burden and incidence trends of zika virus infection among women aged 15–49 years from 2011 to 2021: A systematic analysis

BackgroundZika virus (ZIKV) infection during pregnancy presents a significant health risk in women of reproductive age and their offspring due to severe neurological complications. It is meaningful to assess its global burden and temporal trends. MethodsThis study extracted annual incidence cases and rates of ZIKV among women of reproductive age (15–49 years) between 2011 and 2021 from Global Burden of Diseases (GBD) 2021, including global level, 21 GBD regions, 5 socio-demographic index (SDI) regions, 7 age groups, and 204 countries and territories. Relative percent change in cases and estimated annual percentage change (EAPC) of incidence rates were used to quantify the temporal trends. ResultsThe incidence rate of ZIKV infection exhibited a pronounced peak in 2016 at 174.27 per 100,000 population, with an EAPC of 158.30 % from 2011 to 2016 and −51.86 % from 2016 to 2021 at 3.06 per 100,000 population. And only 5 out of the 21 GBD regions reported ZIKV infection in 2021, predominantly concentrated in Latin America and Caribbean. The outbreaks were primarily concentrated in low-middle and middle SDI regions. In 2021, at the global level, the incidence rates of ZIKV infection among women of reproductive age were similar across different age groups, ranging from 2.41 to 3.39 per 100,000 population. The proportion of ZIKV infection cases was slightly higher in women aged 25–29 and 30–34 years compared to other age groups in 2021, whereas a higher proportion of cases were observed in younger age groups in 2011 and 2016. ConclusionsWomen of reproductive age in Latin America and Caribbean continue to face the threat of ZIKV. Regions with lower SDI had a disproportionately severe burden. Future public health strategies should focus on high-risk areas and populations of reproductive age, enhancing surveillance, prevention, and education efforts to further mitigate the public health threat posed by ZIKV.