Impact of Zika Virus Infection on Human Neural Stem Cell MicroRNA Signatures

The role of small extracellular vesicles in spreading and inhibiting arthropod-borne diseases

Arthropod-borne diseases (ABDs) refer to a group of viral pathogens that affect a wide range of vertebrate hosts, including humans and non-human primates. In addition to being transmitted by mosquitoes and ticks, arthropods can also spread pathogens that cause severe human diseases. On the other hand, extracellular vesicles (EVs) can serve as cross-placental drug delivery vehicles (DDVs) to the fetus and even as antigen-presenting cells (APCs). To this end, the current review aimed to examine the role of small EVs (sEVs) in the transmission and inhibition of arthropod-borne viruses, also known as arboviruses. First, a deeper understanding of the mechanistic aspects of how these vesicles function during insect-pathogen interactions is required. Next, scalability and yield optimization must be addressed while introducing EV-based therapeutics on an industrial scale in order to implement them effectively. Finally,it is recommended to consider that sEV-mediated transfer plays a crucial role in the spread of ABDs. This is because it transfers pathogenic agents between cells within vectors, resulting in subsequent transmission to hosts. Consequently, sEVs provide potential targets for the development of novel therapies that inhibit pathogen replication or reduce arthropod vector populations. Future research in this area should emphasize how these vesicles function within host-vector systems, using advanced imaging techniques - such as high-resolution microscopy (HRM) - and cost-effective methods, in order to produce sufficient quantities for large-scale implementation.

The impact of ZIKV infection on gene expression in neural cells over time

Zika virus (ZIKV) outbreak caused one of the most significant medical emergencies in the Americas due to associated microcephaly in newborns. To evaluate the impact of ZIKV infection on neuronal cells over time, we retrieved gene expression data from several ZIKV-infected samples obtained at different time point post-infection (pi). Differential gene expression analysis was applied at each time point, with more differentially expressed genes (DEG) identified at 72h pi. There were 5 DEGs (PLA2G2F, TMEM71, PKD1L2, UBD, and TNFAIP3 genes) across all timepoints, which clearly distinguished between infected and healthy samples. The highest expression levels of all five genes were identified at 72h pi. Taken together, our results indicate that ZIKV infection greatly impacts human neural cells at early times of infection, with peak perturbation observed at 72h pi. Our analysis revealed that all five DEGs, in samples of ZIKV-infected human neural stem cells, remained highly upregulated across the timepoints evaluated. Moreover, despite the pronounced inflammatory host response observed throughout infection, the impact of ZIKV is variable over time. Finally, the five DEGs identified herein play prominent roles in infection, and could serve to guide future investigations into virus-host interaction, as well as constitute targets for therapeutic drug development.

Regulation of Onecut2 by miR-9-5p in Japanese encephalitis virus infected neural stem/progenitor cells

Japanese encephalitis virus (JEV) is one of the major neurotropic viral infections that is known to dysregulate the homeostasis of neural stem/progenitor cells (NSPCs) and depletes the stem cell pool. NSPCs are multipotent stem cell population of the central nervous system (CNS) which are known to play an important role in the repair of the CNS during insults/injury caused by several factors such as ischemia, neurological disorders, CNS infections, and so on. Viruses have evolved to utilize host factors for their own benefit and during JEV infection, host factors, including the non-coding RNAs such as miRNAs, are reported to be affected, thereby cellular processes regulated by the miRNAs exhibit perturbed functionality. Previous studies from our laboratory have demonstrated the role of JEV infection in dysregulating the function of neural stem cells (NSCs) by altering the cell fate and depleting the stem cell pool leading to a decline in stem cell function in CNS repair mechanism post-infection. JEV-induced alteration in miRNA expression in the NSCs is one of the major interest to us. In prior studies, we have observed an altered expression pattern of certain miRNAs following JEV infection. In this study, we have validated the role of JEV infection in NSCs in altering the expression of miR-9-5p, which is a known regulator of neurogenesis in NSCs. Furthermore, we have validated the interaction of this miRNA with its target, Onecut2 (OC2), in primary NSCs utilizing miRNA mimic and inhibitor transfection experiments. Our findings indicate a possible role of JEV mediated dysregulated interaction between miR-9-5p and its putative target OC2 in NSPCs.

IMPORTANCE

MicroRNAs have emerged as key disease pathogenic markers and potential therapeutic targets. In this study, we solidify this concept by studying a key miRNA, miR-9-5p, in Japanese encephalitis virus infection of neural stem/progenitor cells. miRNA target Onecut2 has a possible role in stem cell pool biology. Here, we show a possible mechanistic axis worth investing in neurotropic viral biology.

Zika Virus-Infected Monocyte Exosomes Mediate Cell-to-Cell Viral Transmission

Zika fever is a reemerging arthropod-borne viral disease; however, Zika virus (ZIKV) can be transmitted by other, non-vector means. Severe Zika fever is characterized by neurological disorders, autoimmunity, or congenital Zika syndrome. Monocytes are primary ZIKV targets in humans and, in response to infection, release extracellular vesicles like exosomes. Exosomes mediate intercellular communication and are involved in the virus's ability to circumvent the immune response, promoting pathological processes. This study aimed to evaluate the role of monocyte exosomes in cell-to-cell viral transmission. We isolated exosomes from ZIKV-infected monocytes (Mø exo ZIKV) by differential ultracentrifugation and identified them by nanoparticle tracking analysis; transmission electron microscopy; and CD63, CD81, TSG101, and Alix detection by cytofluorometry. Purified exosome isolates were obtained by uncoupling from paramagnetic beads or by treatment with UV radiation and RNase A. We found that Mø exo ZIKV carry viral RNA and E/NS1 proteins and that their interaction with naïve cells favors viral transmission, infection, and cell differentiation/activation. These data suggest that Mø exo ZIKV are an efficient alternative pathway for ZIKV infection. Knowledge of these mechanisms contributes to understanding the pathogenesis of severe disease and to the development of new vaccines and therapies.

Strain Variation Can Significantly Modulate the miRNA Response to Zika Virus Infection

Zika virus (ZIKV) is a mosquito-transmitted virus that has emerged as a major public health concern due to its association with neurological disorders in humans, including microcephaly in fetuses. ZIKV infection has been shown to alter the miRNA profile in host cells, and these changes can contain elements that are proviral, while others can be antiviral in action. In this study, the expression of 22 miRNAs in human A549 cells infected with two different ZIKV isolates was investigated. All of the investigated miRNAs showed significant changes in expression at at least one time point examined. Markedly, 18 of the miRNAs examined showed statistically significant differences in expression between the two strains examined. Four miRNAs (miR-21, miR-34a, miR-128 and miR-155) were subsequently selected for further investigation. These four miRNAs were shown to modulate antiviral effects against ZIKV, as downregulation of their expression through anti-miRNA oligonucleotides resulted in increased virus production, whereas their overexpression through miRNA mimics reduced virus production. However, statistically significant changes were again seen when comparing the two strains investigated. Lastly, candidate targets of the miRNAs miR-34a and miR-128 were examined at the level of the mRNA and protein. HSP70 was identified as a target of miR-34a, but, again, the effects were strain type-specific. The two ZIKV strains used in this study differ by only nine amino acids, and the results highlight that consideration must be given to strain type variation when examining the roles of miRNAs in ZIKV, and probably other virus infections.

miRNAs: Targets to Investigate Herpesvirus Infection Associated with Neurological Disorders

Herpesvirus is associated with various neurological disorders and a specific diagnosis is associated with a better prognosis. MicroRNAs (miRNAs) are potential diagnostic and prognostic biomarkers of neurological diseases triggered by herpetic infection. In this review, we discuss miRNAs that have been associated with neurological disorders related to the action of herpesviruses. Human miRNAs and herpesvirus-encoded miRNAs were listed and discussed. This review article will be valuable in stimulating the search for new diagnostic and prognosis alternatives and understanding the role of these miRNAs in neurological diseases triggered by herpesviruses.

Neural stem cell-derived extracellular vesicles: mini players with key roles in neurogenesis, immunomodulation, neuroprotection and aging

Neural stem/progenitor cells (NSPCs) are self-renewing and multipotent cells of the central nervous system where they give rise to neurons, astrocytes and oligodendrocytes both during embryogenesis and throughout adulthood, although only in a few discrete niches. NSPC can integrate and send a plethora of signals not only within the local microenvironment but also at distance, including the systemic macroenvironment. Extracellular vesicles (EVs) are currently envisioned as main players in cell-cell communication in basic and translational neuroscience where they are emerging as an acellular alternative in regenerative medicine. At present NSPC-derived EVs represent a largely unexplored area compared to EVs from other neural sources and EVs from other stem cells, i.e., mesenchymal stem cells. On the other hand, available data suggest that NSPC-derived EVs can play key roles on neurodevelopmental and adult neurogenesis, and they are endowed with neuroprotective and immunomodulatory properties, and even endocrine functions. In this review we specifically highlight major neurogenic and "non-neurogenic" properties of NSPC-EVs, the current knowledge on their peculiar cargos and their potential translational value.

Shared Molecular Signatures Across Zika Virus Infection and Multiple Sclerosis Highlight AP-1 Transcription Factor as a Potential Player in Post-ZIKV MS-Like Phenotypes

Zika virus (ZIKV) is an arbovirus of the Flaviviridae genus that has rapidly disseminated from across the Pacific to the Americas. Robust evidence has indicated a crucial role of ZIKV in congenital virus syndrome, including neonatal microcephaly. Moreover, emerging evidence suggests an association between ZIKV infection and the development of an extensive spectrum of central nervous system inflammatory demyelinating diseases (CNS IDD), such as multiple sclerosis-like clinical phenotypes. However, the underlying mechanisms of host-pathogen neuro-immune interactions remain to be elucidated. This study aimed to identify common transcriptional signatures between multiple sclerosis (MS) and ZIKV infection to generate molecular interaction networks, thereby leading to the identification of deregulated processes and pathways, which could give an insight of these underlying molecular mechanisms. Our investigation included publicly available transcriptomic data from MS patients in either relapse or remission (RR-MS) and datasets of subjects acutely infected by ZIKV for both immune peripheral cells and central nervous system cells. The protein-protein interaction (PPI) analysis showed upregulated AP-1 transcription factors (JUN and FOS) among the top hub and bottleneck genes in RR-MS and ZIKV data. Gene enrichment analysis retrieved a remarkable presence of ontologies and pathways linked to oxidative stress responses, immune cell function, inflammation, interleukin signaling, cell division, and transcriptional regulation commonly enriched in both scenarios. Considering the recent findings concerning AP-1 function in immunological tolerance breakdown, regulation of inflammation, and its function as an oxidative stress sensor, we postulate that the ZIKV trigger may contribute as a boost for the activation of such AP-1-regulated mechanisms that could favor the development of MS-like phenotypes following ZIKV infection in a genetically susceptible individual.

Roles and mechanisms of exosomal microRNAs in viral infections

Exosomes are small extracellular vesicles with a diameter of 30-150 nm that originate from endosomes and fuse with the plasma membrane. They are secreted by almost all kinds of cells and can stably transfer different kinds of cargo from donor to recipient cells, thereby altering cellular functions for assisting cell-to-cell communication. Exosomes derived from virus-infected cells during viral infections are likely to contain different microRNAs (miRNAs) that can be transferred to recipient cells. Exosomes can either promote or suppress viral infections and therefore play a dual role in viral infection. In this review, we summarize the current knowledge about the role of exosomal miRNAs during infection by six important viruses (hepatitis C virus, enterovirus A71, Epstein-Barr virus, human immunodeficiency virus, severe acute respiratory syndrome coronavirus 2, and Zika virus), each of which causes a significant global public health problem. We describe how these exosomal miRNAs, including both donor-cell-derived and virus-encoded miRNAs, modulate the functions of the recipient cell. Lastly, we briefly discuss their potential value for the diagnosis and treatment of viral infections.

microRNAs Control Antiviral Immune Response, Cell Death and Chemotaxis Pathways in Human Neuronal Precursor Cells (NPCs) during Zika Virus Infection

Viral infections have always been a serious burden to public health, increasing morbidity and mortality rates worldwide. Zika virus (ZIKV) is a flavivirus transmitted by the Aedes aegypti vector and the causative agent of severe fetal neuropathogenesis and microcephaly. The virus crosses the placenta and reaches the fetal brain, mainly causing the death of neuronal precursor cells (NPCs), glial inflammation, and subsequent tissue damage. Genetic differences, mainly related to the antiviral immune response and cell death pathways greatly influence the susceptibility to infection. These components are modulated by many factors, including microRNAs (miRNAs). MiRNAs are small noncoding RNAs that regulate post-transcriptionally the overall gene expression, including genes for the neurodevelopment and the formation of neural circuits. In this context, we investigated the pathways and target genes of miRNAs modulated in NPCs infected with ZIKV. We observed downregulation of miR-302b, miR-302c and miR-194, whereas miR-30c was upregulated in ZIKV infected human NPCs in vitro. The analysis of a public dataset of ZIKV-infected human NPCs evidenced 262 upregulated and 3 downregulated genes, of which 142 were the target of the aforementioned miRNAs. Further, we confirmed a correlation between miRNA and target genes affecting pathways related to antiviral immune response, cell death and immune cells chemotaxis, all of which could contribute to the establishment of microcephaly and brain lesions. Here, we suggest that miRNAs target gene expression in infected NPCs, directly contributing to the pathogenesis of fetal microcephaly.

Involvement of host microRNAs in flavivirus-induced neuropathology: An update

Flaviviruses are a spectrum of vector-borne RNA viruses that cause potentially severe diseases in humans including encephalitis, acute-flaccid paralysis, cognitive disorders and foetal abnormalities. Japanese encephalitis virus (JEV), Zika virus (ZIKV), West Nile virus (WNV) and Dengue virus (DENV) are globally emerging pathogens that lead to epidemics and outbreaks with continued transmission to newer geographical areas over time. In the past decade, studies have focussed on understanding the pathogenic mechanisms of these viruses in a bid to alleviate their disease burden. MicroRNAs (miRNAs) are short single-stranded RNAs that have emerged as master-regulators of cellular gene expression. The dynamics of miRNAs within a cell have the capacity to modulate hundreds of genes and, consequently, their physiological manifestation. Increasing evidence suggests their role in host response to disease and infection including cell survival, intracellular viral replication and immune activation. In this review, we aim to comprehensively update published evidence on the role of miRNAs in host cells infected with the common neurotropic flaviviruses, with an increased focus on neuropathogenic mechanisms. In addition, we briefly cover therapeutic advancements made in the context of miRNA-based antiviral strategies.

MiR-103a-3p Promotes Zika Virus Replication by Targeting OTU Deubiquitinase 4 to Activate p38 Mitogen-Activated Protein Kinase Signaling Pathway

Background

MicroRNAs (miRNAs) play critical roles in regulating virus infection and replication. However, the mechanism by which miRNA regulates Zika virus (ZIKV) replication remains elusive. We aim to explore how the differentially expressed miR-103a-3p regulates ZIKV replication and to clarify the underlying molecular mechanism.

Methods

Small RNA sequencing (RNA-Seq) was performed to identify differentially expressed miRNAs in A549 cells with or without ZIKV infection and some of the dysregulated miRNAs were validated by quantitative real time PCR (qRT-PCR). The effect of miR-103a-3p on ZIKV replication was examined by transfecting miR-103a-3p mimic or negative control (NC) into A549 cells with or without p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580 and expression levels of ZIKV NS5 mRNA and NS1 protein were detected by qRT-PCR and Western blot, respectively. The potential target genes for miR-103a-3p were predicted by four algorithms and further validated by mutation analysis through luciferase reporter assay. The predicated target gene OTU deubiquitinase (DUB) 4 (OTUD4) was over-expressed by plasmid transfection or silenced by siRNA transfection into cells prior to ZIKV infection. Activation status of p38 MAPK signaling pathway was revealed by looking at the phosphorylation levels of p38 (p-p38) and HSP27 (p-HSP27) by Western blot.

Results

Thirty-five differentially expressed miRNAs in ZIKV-infected A549 cells were identified by RNA-Seq analysis. Five upregulated and five downregulated miRNAs were further validated by qRT-PCR. One of the validated upregulated miRNAs, miR-103a-3p significantly stimulated ZIKV replication both at mRNA (NS5) and protein (NS1) levels. We found p38 MAPK signaling was activated following ZIKV infection, as demonstrated by the increased expression of the phosphorylation of p38 MAPK and HSP27. Blocking p38 MAPK signaling pathway using SB203580 inhibited ZIKV replication and attenuated the stimulating effect of miR-103a-3p on ZIKV replication. We further identified OTUD4 as a direct target gene of miR-103a-3p. MiR-103a-3p over-expression or OTUD4 silencing activated p38 MAPK signaling and enhanced ZIKV replication. In contrast, OTUD4 over-expression inhibited p38 MAPK activation and decreased ZIKV replication. In addition, OTUD4 over-expression attenuated the stimulating effect of miR-103a-3p on ZIKV replication and activation of p38 MAPK signaling.

Conclusion

Zika virus infection induced the expression of miR-103a-3p, which subsequently activated p38 MAPK signaling pathway by targeting OTUD4 to facilitate ZIKV replication.

Machine Learning Identifies Cellular and Exosomal MicroRNA Signatures of Lyssavirus Infection in Human Stem Cell-Derived Neurons

Despite being vaccine preventable, rabies (lyssavirus) still has a significant impact on global mortality, disproportionally affecting children under 15 years of age. This neurotropic virus is deft at avoiding the immune system while travelling through neurons to the brain. Until recently, research efforts into the role of non-coding RNAs in rabies pathogenicity and detection have been hampered by a lack of human in vitro neuronal models. Here, we utilized our previously described human stem cell-derived neural model to investigate the effect of lyssavirus infection on microRNA (miRNA) expression in human neural cells and their secreted exosomes. Conventional differential expression analysis identified 25 cellular and 16 exosomal miRNAs that were significantly altered (FDR adjusted P-value <0.05) in response to different lyssavirus strains. Supervised machine learning algorithms determined 6 cellular miRNAs (miR-99b-5p, miR-346, miR-5701, miR-138-2-3p, miR-651-5p, and miR-7977) were indicative of lyssavirus infection (100% accuracy), with the first four miRNAs having previously established roles in neuronal function, or panic and impulsivity-related behaviors. Another 4-miRNA signatures in exosomes (miR-25-3p, miR-26b-5p, miR-218-5p, miR-598-3p) can independently predict lyssavirus infected cells with >99% accuracy. Identification of these robust lyssavirus miRNA signatures offers further insight into neural lineage responses to infection and provides a foundation for utilizing exosome miRNAs in the development of next-generation molecular diagnostics for rabies.

Involvement of host microRNAs in flavivirus-induced neuropathology: An update

Flaviviruses are a spectrum of vector-borne RNA viruses that cause potentially severe diseases in humans including encephalitis, acute-flaccid paralysis, cognitive disorders and foetal abnormalities. Japanese encephalitis virus (JEV), Zika virus (ZIKV), West Nile virus (WNV) and Dengue virus (DENV) are globally emerging pathogens that lead to epidemics and outbreaks with continued transmission to newer geographical areas over time. In the past decade, studies have focussed on understanding the pathogenic mechanisms of these viruses in a bid to alleviate their disease burden. MicroRNAs (miRNAs) are short single-stranded RNAs that have emerged as master-regulators of cellular gene expression. The dynamics of miRNAs within a cell have the capacity to modulate hundreds of genes and, consequently, their physiological manifestation. Increasing evidence suggests their role in host response to disease and infection including cell survival, intracellular viral replication and immune activation. In this review, we aim to comprehensively update published evidence on the role of miRNAs in host cells infected with the common neurotropic flaviviruses, with an increased focus on neuropathogenic mechanisms. In addition, we briefly cover therapeutic advancements made in the context of miRNA-based antiviral strategies.

Catch me if you can - the crosstalk of ZIKV and the restriction factor Tetherin

Zika virus (ZIKV) is a flavivirus that is mainly transmitted by Aedes mosquitos and normally causes mild symptoms. During the outbreak in the Americas in 2015, it was associated with more severe implications, like microcephaly in new-borns and the Gullain-Barré syndrome. The lack of specific vaccines and cures strengthen the need for a deeper understanding of the virus life cycle and virus-host interactions. The restriction factor tetherin (THN) is an interferon-inducible cellular protein with broad antiviral properties. It is known to inhibit the release of various enveloped viruses by tethering them to each other and to the cell membrane, thereby preventing their further spread. On the other hand, different viruses have developed various escape strategies against THN. Analysis of the crosstalk between ZIKV and THN revealed that in spite of a strong induction of THN mRNA expression in ZIKV-infected cells, this is not reflected by an elevated protein level of THN. Contrariwise, the THN protein level is decreased due to a reduced half-life. The increased degradation of THN in ZIKV infected cells involves the endo-lysosomal system, but does not depend on the early steps of autophagy. Enrichment of THN by depletion of the ESCRT-0 protein HRS diminishes ZIKV release and spread, which points out the capacity of THN to restrict ZIKV and explains the enhanced THN degradation in infected cells as an effective viral escape strategy. Importance Although tetherin expression is strongly induced by ZIKV infection there is a reduction in the amount of tetherin protein. This is due to an enhanced lysosomal degradation. However, if tetherin level is rescued release of ZIKV is impaired. This shows that tetherin is a restriction factor for ZIKV and the induction of an efficient degradation represents a viral escape strategy. To our knowledge this is the first study that describes and characterizes tetherin as an restriction factor for ZIKV life cycle.

Cellular miR-150-5p may have a crucial role to play in the biology of SARS-CoV-2 infection by regulating nsp10 gene

The role for circulating miRNAs as biomarkers of the COVID-19 disease remains uncertain. We analysed the circulating miRNA profile in twelve COVID-19 patients with moderate-severe disease. This analysis was conducted by performing next generation sequencing (NGS) followed by real-time polymerase chain reaction (RT-qPCR). Compared with healthy controls, we detected significant changes in the circulating miRNA profile of COVID-19 patients. The miRNAs that were significantly altered in all the COVID-19 patients were miR-150-5p, miR-375, miR-122-5p, miR-494-3p, miR-3197, miR-4690-5p, miR-1915-3p, and miR-3652. Infection assays performed using miRNA mimics in HEK-293 T cells determined miR-150-5p to have a crucial role in SARS-CoV-2 infection and this was based on the following data: (i) miR-150-5p mimic lowered in vitro SARS-CoV-2 infection; (ii) miR-150-5p inhibitor reversed the effects of miR-150-5p mimic on SARS-CoV-2 infection of cells; and (iii) a novel miRNA recognition element (MRE) was identified in the coding strand of SARS-CoV-2 nsp10, the expression of which could be inhibited by miR-150-5p mimic. Our findings identified crucial miRNA footprints in COVID-19 patients with moderate-severe disease. A combination of co-transfection and Western blotting experiments also determined the ability of miR-150-5p to inhibit SARS-CoV-2 infection via directly interacting with MRE in the coding strand of nsp10. Our investigation showed that a sharp decline in the miR-150-5p plasma levels in COVID-19 patients may support enhanced SARS-CoV-2 infection. Furthermore, this study provides insight into one possible mechanism by which COVID-19-induced changes to miR-150-5p levels may promote SARS-CoV-2 infection via modulating nsp10 expression.

ZIKV Infection and miRNA Network in Pathogenesis and Immune Response

Over the years, viral infections have caused severe illness in humans. Zika Virus (ZIKV) is a flavivirus transmitted by mosquito vectors that leads to notable neurological impairment, whose most dramatic impact is the Congenital ZIKV Syndrome (CZS). ZIKV targets neuronal precursor cells leading to apoptosis and further impairment of neuronal development, causing microcephaly, lissencephaly, ventriculomegaly, and calcifications. Several regulators of biological processes are involved in CZS development, and in this context, microRNAs (miRNAs) seem to have a fundamental role. miRNAs are important regulators of protein translation, as they form the RISC silencing complex and interact with complementary mRNA target sequences to further post-transcriptional repression. In this context, little is known about their participation in the pathogenesis of viral infections. In this review, we discuss how miRNAs could relate to ZIKV and other flavivirus infections.

Inter-regulatory role of microRNAs in interaction between viruses and stem cells

MicroRNAs (miRNAs) are well known for post-transcriptional regulatory ability over specific mRNA targets. miRNAs exhibit temporal or tissue-specific expression patterns and regulate the cell and tissue developmental pathways. They also have determinative roles in production and differentiation of multiple lineages of stem cells and might have therapeutic advantages. miRNAs are a part of some viruses' regulatory machinery, not a byproduct. The trace of miRNAs was detected in the genomes of viruses and regulation of cell reprograming and viral pathogenesis. Combination of inter-regulatory systems has been detected for miRNAs during viral infections in stem cells. Contraction between viruses and stem cells may be helpful in therapeutic tactics, pathogenesis, controlling viral infections and defining stem cell developmental strategies that is programmed by miRNAs as a tool. Therefore, in this review we intended to study the inter-regulatory role of miRNAs in the interaction between viruses and stem cells and tried to explain the advantages of miRNA regulatory potentials, which make a new landscape for future studies.

Zika virus E protein dysregulate mir-204/WNT2 signalling in human fetal neural stem cells

Zika Virus (ZIKV) belongs to the family of flaviviruses, and is neurotrophic. It has been known to cause severe congenital disabilities including microcephaly in neonates. The virus has a specific preference towards neural stem cells (NSCs). ZIKV impairs proliferation and differentiation of NSCs during in-utero brain development of the fetus. However, molecular pathways involved in ZIKV induced alteration in NSCs are yet to be explored. In our previous study, we have described that ZIKV E protein dysregulates microRNA circuitry in NSCs and also impairs their proliferative and differentiation abilities. WNT signalling was found to be the target of differentially expressed miRNAs as suggested by PANTHER PATHWAY analysis of differentially expressed miRNA targets. In our current follow-up study, we investigate that WNT2 is downregulated in response to ZIKV E protein in human fetal NSCs and WNT2 is the molecular target of microRNA miR-204-5p. We provide pieces of evidences that miR-204-5p/WNT2 axis is involved in ZIKV induced impairment in the proliferation and immature differentiation of neural stem cells.