Project description:Congenital human cytomegalovirus (HCMV) infection is one of the leading prenatal causes of mental retardation and congenital deformities world-wide. Access to cultured human neuronal lineages, necessary to understand the species specific pathogenic effects of HCMV has been limited by difficulties in sustaining primary cultures. Neuronal cells derived from human induced pluripotent stem (iPS) cells now provide a novel opportunity to investigate HCMV pathogenesis. We derived iPS cells from human adult fibroblasts and induced neural lineages to investigate their permissiveness to infection with HCMV strain Ad169. Analysis of iPS cells and nearly pure populations of iPS-derived neural stem cells (NSCs), neuroprogenitor cells (NPCs) and neurons suggests that (i) iPS cells are not permissive to HCMV infection; (ii) Neural stem cells have impaired differentiation when infected by HCMV; (iii) NPCs are fully permissive for HCMV infection; the supernatant from infected neural stem cells and NPCs (but not mock infected cells) induced cytopathic effects in human fibroblasts; (iv) most iPS-derived neurons are not permissive to HCMV infection; and (v) infected neurons have impaired calcium influx in response to glutamate. Our approach offers powerful cellular models to investigate the effect of neurotropic viral agents on human neurodevelopment. Adherent monolayer culture of neural progenitor cells (NPCs) were either infected with HCMV Ad169 in triplicate, with each individual sample harvested separately to provide biological replicates for expression analysis. Infected and mock-infected cells were harvested 24 h p.i. RNA. NPCs were 70-80% confluence.
Project description:Congenital human cytomegalovirus (HCMV) infection is the leading infectious cause of birth defects, including neurodevelopmental disorders. HCMV infection mainly targets neural progenitor cells (NPCs) in fetal brains, inducing abnormal differentiation by altering key regulatory pathways. HCMV expresses a series of viral miRNAs during infection, but their roles, particularly in NPCs, are not fully understood. In this study, we characterized expression profiles of both cellular and viral miRNAs in HCMV-infected NPCs by microarray analysis during early infection time points and investigated the primary effects of these miRNAs on regulating NPC fate. While expression of most cellular miRNAs was unaffected by HCMV infection, one cellular miRNA was upregulated and six were downregulated from 2 to 24 h post infection. Moreover, of 17 HCMV miRNAs evaluated, six were differentially expressed in HCMV-infected NPCs during early infection time points.
Project description:In this study, proteomic analysis on ZIKV-infected primary human fetal neural progenitor cells (NPCs) revealed that virus infection altered levels of cellular proteins involved in NPC proliferation, differentiation and migration.
Project description:Congenital human cytomegalovirus (HCMV) infection is one of the leading prenatal causes of mental retardation and congenital deformities world-wide. Access to cultured human neuronal lineages, necessary to understand the species specific pathogenic effects of HCMV has been limited by difficulties in sustaining primary cultures. Neuronal cells derived from human induced pluripotent stem (iPS) cells now provide a novel opportunity to investigate HCMV pathogenesis. We derived iPS cells from human adult fibroblasts and induced neural lineages to investigate their permissiveness to infection with HCMV strain Ad169. Analysis of iPS cells and nearly pure populations of iPS-derived neural stem cells (NSCs), neuroprogenitor cells (NPCs) and neurons suggests that (i) iPS cells are not permissive to HCMV infection; (ii) Neural stem cells have impaired differentiation when infected by HCMV; (iii) NPCs are fully permissive for HCMV infection; the supernatant from infected neural stem cells and NPCs (but not mock infected cells) induced cytopathic effects in human fibroblasts; (iv) most iPS-derived neurons are not permissive to HCMV infection; and (v) infected neurons have impaired calcium influx in response to glutamate. Our approach offers powerful cellular models to investigate the effect of neurotropic viral agents on human neurodevelopment.
Project description:Zika virus (ZIKV) is a mosquito-borne virus that can have dramatic neurodevelopmental consequences when infection occurs in utero. Previous studies demonstrated that ZIKV downregulates the master regulator of nonsense mediated decay, UPF1. To examine whether this process contributes to disruption of neural development, we investigated the effect of ZIKV infection on UPF1 interaction with host RNA in neural progenitor cells. Here, we show that ZIKV-mediated disruption of UPF1 function in neural progenitor cells causes retention of mRNA in the nucleus, resulting in decreased protein levels of specific transcripts involved in neural differentiation.
Project description:Stem and progenitor cells maintain the tissue they reside in for life by regulating the balance between proliferation and differentiation. How this is done is not well understood. Here, we report that the human exosome maintains progenitor cell function. The expression of several subunits of the exosome were found to be enriched in epidermal progenitor cells, which were required to retain proliferative capacity and to prevent premature differentiation. Loss of PM/Scl-75 also known as EXOSC9, a key subunit of the exosome complex, resulted in loss of cells from the progenitor cell compartment, premature differentiation, and loss of epidermal tissue. EXOSC9 promotes self-renewal and prevents premature differentiation by maintaining transcript levels of a transcription factor necessary for epidermal differentiation, GRHL3, at low levels through mRNA degradation. These data demonstrate that control of differentiation specific transcription factors through mRNA degradation is required for progenitor cell maintenance in mammalian tissue. Refer to publication (Mistry et. Cell Stem Cell 2012) for more detail For gene expression profiling, cultured primary human keratinocytes were knocked down for EXOSC9, EXOSC9 and GRHL3, or control. RNA was harvested from the cells 5 days after knockdown. Microarray analysis using Affymetrix HG-U133 2.0 plus arrays was performed on duplicate samples. Significantly changed genes were identified as previously described(Sen et al., 2010).