Human cytomegalovirus infection impairs neural differentiation via repressing sterol regulatory element binding protein 2-mediated cholesterol biosynthesis.

Congenital human cytomegalovirus (HCMV) infection is a major cause of abnormalities and disorders in the central nervous system (CNS) and/or the peripheral nervous system (PNS). However, the complete pathogenesis of neural differentiation disorders caused by HCMV infection remains to be fully elucidated. Stem cells from human exfoliated deciduous teeth (SHEDs) are mesenchymal stem cells (MSCs) with a high proliferation and neurogenic differentiation capacity. Since SHEDs originate from the neural crest of the early embryonic ectoderm, SHEDs were hypothesized to serve as a promising cell line for investigating the pathogenesis of neural differentiation disorders in the PNS caused by congenital HCMV infection. In this work, SHEDs were demonstrated to be fully permissive to HCMV infection and the virus was able to complete its life cycle in SHEDs. Under neurogenic inductive conditions, HCMV infection of SHEDs caused an abnormal neural morphology. The expression of stem/neural cell markers was also disturbed by HCMV infection. The impairment of neural differentiation was mainly due to a reduction of intracellular cholesterol levels caused by HCMV infection. Sterol regulatory element binding protein-2 (SREBP2) is a critical transcription regulator that guides cholesterol synthesis. HCMV infection was shown to hinder the migration of SREBP2 into nucleus and resulted in perinuclear aggregations of SREBP2 during neural differentiation. Our findings provide new insights into the prevention and treatment of nervous system diseases caused by congenital HCMV infection.

Single walled carbon nanotubes band gap width measurement and the influence of nitrogen doping research.

The adjustment and measurement of the band gap width of single-walled carbon nanotubes are crucial for optimizing the design and enhancing the performance of carbon-based devices. This study utilizes the relationship between the band gap and temperature of semiconductor-based carbon nanotubes. The electrical conductivity of carbon nanotubes was obtained at various temperatures, and the corresponding band gap width (0.57 eV) was determined. The introduction of nitrogen results in a reduction of the band gap width and an increase in current flow between the device source and drain electrodes. Theoretical calculation demonstrated that nitrogen doping not only increases the conductivity of carbon nanotubes but also effectively inhibits the Schottky barrier between carbon nanotubes and metal electrodes. The Schottky barrier and the internal electric field can be effectively modulated via nitrogen doping in carbon nanotubes, which enhances the performance of carbon-based devices.

Identification and characterization of human cytomegalovirus-encoded circular RNAs.

Circular RNA (circRNA) exists extensively and plays essential roles in serving as microRNA (miRNA) or protein sponges and protein scaffolding in many organisms. However, the profiles and potential functions of the virus-encoded circRNA, including human cytomegalovirus (HCMV)-encoded circular RNAs, remain unclear. In the present study, HCMV-encoded circRNAs profile in human embryonic lung fibroblasts (HELF) with lytic infection was investigated using RNA deep sequencing and bioinformatics analysis. In total, 629 HCMV-encoded circRNAs were identified with various expression patterns in our results. The full sequences and alternative splicings of circUS12, circUL55, and circUL89 were verified by reverse transcriptase-PCR (RT-PCR) with divergent primers followed and Sanger sequencing. Transcription of circUL89 was validated by Northern blot. The HCMV-encoded circRNA-miRNA network analyses revealed the potential function of HCMV-encoded circRNAs during HCMV infection in HELFs. Collectively, HCMV infection deduced abundant HCMV-associated circRNAs during infection, and the HCMV-encoded circRNAs might play important roles in benefiting HCMV infection.

Human Cytomegalovirus Influences Host circRNA Transcriptions during Productive Infection.

Human cytomegalovirus (HCMV) is a double-strand DNA virus widely infected in human. Circular RNAs (circRNAs) are non-coding RNAs with most functions of which keep unknown, and the effects of HCMV productive infection on host circRNA transcriptions remain unclear. In this study, we profiled 283 host circRNAs that significantly altered by HCMV productive infection in human embryonic lung fibroblasts (HELF) by RNA deep sequencing and bioinformatics analysis. Among these, circSP100, circMAP3K1, circPLEKHM1, and circTRIO were validated for their transcriptions and sequences. Furthermore, characteristics of circSP100 were investigated by RT-qPCR and northern blot. It was implied that circSP100 was produced from the sense strand of the SP100 gene containing six exons. Kinetics of circSP100 and SP100 mRNA were significantly different after infection: circSP100 levels increased gradually along with infection, whereas SP100 mRNA levels increased in the beginning and dropped at 24 h post-infection (hpi). Meanwhile, a total number of 257 proteins, including 10 HCMV encoding proteins, were identified potentially binding to cytoplasmic circSP100 by RNA antisense purification (RAP) and mass spectrometry. Enrichment analysis showed these proteins were mainly involved in the spliceosome, protein processing, ribosome, and phagosome pathways, suggesting multiple functions of circSP100 during HCMV infection.

Levels of human cytomegalovirus miR-US25-1-5p and miR-UL112-3p in serum extracellular vesicles from infants with HCMV active infection are significantly correlated with liver damage.

Human cytomegalovirus (HCMV)-encoded microRNAs (miRNAs) are involved in posttranscriptional regulation of gene expression. Extracellular vesicles (EVs) can incorporate miRNAs. Relationship between HCMV infection and miRNAs in EVs remains unknown. EVs were isolated from supernatants of human embryonic lung fibroblasts (HELF) cells. Profiles of miRNAs in EVs were analyzed by deep sequencing. Dynamics of candidate viral miRNAs transportation via EVs was investigated using TaqMan PCR. Levels of candidate viral miRNAs in serum EVs from infants with HCMV active infection were detected and analyzed with their clinical index levels. A total of 16 HCMV miRNAs were found in EVs from infected HELF. Levels of miR-US25-1-5p and miR-UL112-3p in EVs increased at 6 h post-infection and were correlated with those in cells (for miR-US25-1-5p: r2 = 0.9375, p value < 0.05; for miR-UL112-3p: r2 = 0.7557, p value < 0.05). Viral miRNAs were transported into recipient cells at 2 h post-incubation. Moreover, levels of miR-US25-1-5p in serum EVs showed positive correlations with serum levels of γ-glutamyl transpeptidase, direct bilirubin, and total bile acid. Levels of miR-UL112-3p in serum EVs showed a positive correlation with serum levels of direct bilirubin. HCMV miRNAs could be transported to uninfected cells via EVs. Levels of miR-US25-1-5p and miR-UL112-3p in serum EVs from infants with HCMV active infection were significantly correlated with liver damage.

Association of GSTT1, GSTM1 and CYP1A1 polymorphisms with susceptibility to systemic lupus erythematosus in the Chinese population.

BACKGROUND: GSTT1, GSTM1, CYP1A1 are enzymes responsible for the detoxification of the toxicant which may be involved in the development of systemic lupus erythematosus (SLE). We examined the relationship between the risk of SLE and the polymorphisms of these genes in the Chinese population. METHODS: Samples from 298 SLE patients and 284 healthy controls were collected. Polymerase chain reaction-restriction fragments length polymorphism (PCR-RFLP) was used to analyze the genotypes of CYP1A1 m2 and m4, while multiplex PCR was used to analyze the genotypes of GSTT1 and GSTM1. RESULTS: Statistically significant difference was observed in genotypes for GSTM1 (p=0.003, OR 1.66 [95% CI 1.19-2.32]), but not for GSTT1 (p=0.119, OR 0.77 [95% CI 0.56-1.07]), in the SLE patients as compared with the controls. Combinational analysis for double-null deletion of both GSTT1 and GSTM1 showed no significant difference (p=0.863, OR 1.03 [95% CI 0.70-1.52]). Significant difference was observed in the genotype frequencies (p=0.013), but not in the allele frequencies (p=0.444, OR 0.90 [95% CI 0.70-1.17]), of CYP1A1 m2. All candidates have a wild-type genotype for CYP1A1 m4. CONCLUSIONS: Polymorphisms of GSTM1 are associated with SLE in the Chinese population.