Profound downregulation of neural transcription factor Npas4 and Nr4a family in fetal mice neurons infected with Zika virus

Abstract

Zika virus (ZIKV) infection of neurons leads to neurological complications and congenital malformations of the brain of neonates. To date, ZIKV mechanism of infection and pathogenesis is not entirely understood and different studies on gene regulation of ZIKV-infected cells have identified a dysregulation of inflammatory and stem cell maintenance pathways. MicroRNAs (miRNAs) are post-transcriptional regulators of cellular genes and they contribute to cell development in normal function and disease. Previous reports with integrative analyses of messenger RNAs (mRNAs) and miRNAs during ZIKV infection have not identified neurological pathway defects. We hypothesized that dysregulation of pathways involved in neurological functions will be identified by RNA profiling of ZIKV-infected fetal neurons. We therefore used microarrays to analyze gene expression levels following ZIKV infection of fetal murine neurons. We observed that the expression levels of transcription factors such as neural PAS domain protein 4 (Npas4) and of three members of the orphan nuclear receptor 4 (Nr4a) were severely decreased after viral infection. We confirmed that their downregulation was at both the mRNA level and at the protein level. The dysregulation of these transcription factors has been previously linked to aberrant neural functions and development. We next examined the miRNA expression profile in infected primary murine neurons by microarray and found that various miRNAs were dysregulated upon ZIKV infection. An integrative analysis of the differentially expressed miRNAs and mRNAs indicated that miR-7013-5p targets Nr4a3 gene. Using miRmimics, we corroborated that miR-7013-5p downregulates Nr4a3 mRNA and protein levels. Our data identify a profound dysregulation of neural transcription factors with an overexpression of miR-7013-5p that results in decreased Nr4a3 expression, likely a main contributor to ZIKV-induced neuronal dysfunction.

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

“…A number of studies have previously investigated the involvement of miRNAs in ZIKV infection [24,[62][63][64][65][66][67][68][69][70][71][72][73][74][75][76][77]. These studies have variously identified the regulation of miR-302b, miR-302c, miR-194 and miR-30c in ZIKV-infected human NPCs in vitro [73], miR-146a in ZIKV-infected human microglial cells [75], hsa-miR-101-3p in ZIKV-infected human brain microvascular endothelial cells [67], mir-204 in human fetal neural stem cells as a consequence of ZIKV E protein expression [66], miR-7013-5p in ZIKV-infected fetal mouse neurons [62], miR-9 in ZIKV-infected mice [24] and miR-30e-3p, miR-30e-5p and miR-17-5p in ZIKV-infected astrocytes [70].…”

ZIKV infection differentially affects the transcriptional profiles in HTR8 and U251 cells

“…Consistently, previous studies have suggested that overactive immune and cytokine responses are associated with the impairment of astrocytes induced by ZIKV ( Li et al., 2018 ). In addition, pro-inflammatory cytokines, chemokines, and nitric oxide produced by glial cells may be a contributing mechanism of ZIKV causing foetal brain damage ( Bobermin et al., 2020 ), by enhancing neuronal damage and cell death caused by direct ZIKV infection of neurons ( Alpuche-Lazcano et al., 2021 ; Hughes et al., 2016 ; Lin et al., 2017 ; Oh et al., 2017 ). Thus, the DEGs identified in this study should be studied in detail to determine their roles in ZIKV pathogenesis.…”

“…Studies conducted in animal models have suggested that the main mechanism by which ZIKV causes brain damage in the foetus is through direct neuronal infection. These studies have consistently demonstrated that ZIKV can infect the neurons, resulting in cell death and impaired neurodevelopment, ultimately leading to the development of microcephaly ( Alpuche-Lazcano et al., 2021 ; Hughes et al., 2016 ; Lin et al., 2017 ; Oh et al., 2017 ). In addition to neural cells, studies have shown that glial cells, including microglia and astrocytes, are also significant targets of ZIKV infection in the brain ( Jorgačevski et al., 2019 ; Manet et al., 2022 ; van den Pol et al., 2017 ).…”