RESUMEN
miRNAs, small non-coding RNAs that regulate gene expression, are involved in various pathological processes, including viral infections. Virus infections may interfere with the miRNA pathway through the inhibition of genes involved in miRNA biogenesis. A reduction in the number and the levels of miRNAs expressed in nasopharyngeal swabs of patients with severe COVID-19 was lately observed by us, pointing towards the potential of miRNAs as possible diagnostic or prognostic biomarkers for predicting outcomes among patients with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. The objective of the present study was to investigate whether SARS-CoV-2 infection influences the expression levels of messenger RNAs (mRNAs) of key genes involved in miRNA biogenesis. mRNA levels of AGO2, DICER1, DGCR8, DROSHA, and Exportin-5 (XPO5) were measured by quantitative reverse-transcription polymerase chain reaction (RT-qPCR) in nasopharyngeal swab specimens from patients with COVID-19 and controls, as well as in cells infected with SARS-CoV-2 in vitro. Our data showed that the mRNA expression levels of AGO2, DICER1, DGCR8, DROSHA, and XPO5 were not significantly different in patients with severe COVID-19 when compared to patients with non-severe COVID-19 and controls. Similarly, the mRNA expression of these genes was not affected by SARS-CoV-2 infection in NHBE and Calu-3 cells. However, in Vero E6 cells, AGO2, DICER1, DGCR8, and XPO5 mRNA levels were slightly upregulated 24 h after infection with SARS-CoV-2. In conclusion, we did not find evidence for downregulation of mRNA levels of miRNA biogenesis genes during SARS-CoV-2 infection, neither ex vivo nor in vitro.
Asunto(s)
COVID-19 , MicroARNs , Humanos , MicroARNs/genética , MicroARNs/metabolismo , COVID-19/genética , SARS-CoV-2/genética , SARS-CoV-2/metabolismo , Proteínas de Unión al ARN/metabolismo , ARN Mensajero/genética , Ribonucleasa III/genética , Ribonucleasa III/metabolismo , ARN Helicasas DEAD-box/genética , ARN Helicasas DEAD-box/metabolismo , Carioferinas/genéticaRESUMEN
BACKGROUND: The aim of this study was to evaluate the expression of four up/down-regulated inflammatory miRNAs and their mRNA targets in the serum samples of COVID-19 patients with different grades. Also, we investigated the relative expression of these miRNAs and mRNAs during hospitalization. METHODS: In this cross-sectional study, 5 mL of blood sample were taken from COVID-19 patients with different grades and during hospitalization from several health centers of Yazd, Tehran, and Zahedan province of Iran from December 20, 2020 to March 2, 2021. The relative expression of miRNAs and mRNAs was evaluated by q-PCR. RESULTS: We found that the relative expression of hsa-miR-31-3p, hsa-miR-29a-3p, and hsa-miR-126-3p was significantly decreased and the relative expression of their mRNA targets (ZMYM5, COL5A3, and CAMSAP1) was significantly increased with the increase of disease grade. Conversely, the relative expression of hsa-miR-17-3p was significantly increased and its mRNA target (DICER1) was significantly decreased with the increase of disease grade. This pattern was exactly seen during hospitalization of COVID-19 patients who did not respond to treatment. In COVID-19 patients who responded to treatment, the expression of selected miRNAs and their mRNA targets returned to the normal level. A negative significant correlation was seen between (1) the expression of hsa-miR-31-3p and ZMYM5, (2) hsa-miR-29a-3p and COL5A3, (3) hsa-miR-126-3p and CAMSAP1, and (4) hsa-miR-17-3p and DICER1 in COVID-19 patients with any grade (P < 0.05) and during hospitalization. CONCLUSIONS: In this study, we gained a more accurate understanding of the expression of up/down-regulated inflammatory miRNAs in the blood of COVID-19 patients. The obtained data may help us in the diagnosis and prognosis of COVID-19. TRIAL REGISTRATION: The ethics committee of Zahedan University of Medical Sciences, Zahedan, Iran. (Ethical Code: IR.ZAUMS.REC.1399.316) was registered for this project.
Asunto(s)
COVID-19/genética , Perfilación de la Expresión Génica , MicroARNs/genética , ARN Mensajero/genética , COVID-19/sangre , COVID-19/virología , Proteínas Portadoras/genética , Colágeno/genética , Estudios Transversales , ARN Helicasas DEAD-box/genética , Hospitalización/estadística & datos numéricos , Humanos , Irán , Proteínas Asociadas a Microtúbulos/genética , Proteínas Nucleares/genética , Ribonucleasa III/genética , SARS-CoV-2/fisiología , Índice de Severidad de la EnfermedadRESUMEN
In mammals, early resistance to viruses relies on interferons, which protect differentiated cells but not stem cells from viral replication. Many other organisms rely instead on RNA interference (RNAi) mediated by a specialized Dicer protein that cleaves viral double-stranded RNA. Whether RNAi also contributes to mammalian antiviral immunity remains controversial. We identified an isoform of Dicer, named antiviral Dicer (aviD), that protects tissue stem cells from RNA viruses-including Zika virus and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-by dicing viral double-stranded RNA to orchestrate antiviral RNAi. Our work sheds light on the molecular regulation of antiviral RNAi in mammalian innate immunity, in which different cell-intrinsic antiviral pathways can be tailored to the differentiation status of cells.