miRNAs: The Key Regulator of COVID-19 Disease

Alternations in miR-155 and miR-200 serum levels can serve as biomarkers for COVID-19 in the post-mass vaccination era

BACKGROUND

Mass vaccination and natural immunity reduced the severity of COVID-19 cases. SARS-CoV-2 ongoing genome variations imply the use of confirmatory serologic biomarkers besides PCR for reliable diagnosis. MicroRNA molecules are intrinsic components of the innate immune system. The expression of miR155-5p and miR200c-3p was previously correlated with SARS-CoV-2 pathogenesis. This case-control study was conducted during the third peak of the COVID-19 pandemic in Egypt and aimed to calculate the accuracy of miR155-5p and miR200c-3p as biomarkers for COVID-19.

METHODS AND RESULTS

Thirty out of 400 COVID-19 patients at a main University hospital in Alexandria were included in the study along with 20 age-matched healthy controls. Plasma samples were collected for total and differential CBC. Relative quantitation of miR155-5p and miR200c-3p expression from WBCs was done by RT-qPCR. The expression of miR155-5p and miR200c-3p was positively correlated and was significantly downregulated in COVID-19 patients compared to the healthy control group (p ˂ 0.005). Both miR155-5p and miR200c-3p were of 76% and 74% accuracy as diagnostic biomarkers of COVID-19, respectively. Regarding the differentiation between mild and moderate cases, their accuracy was 80% and 70%, respectively.

CONCLUSIONS

miR155-5p and miR200c-3p expression can be used to confirm the diagnosis of COVID-19 and discriminate between mild and moderate cases, with a moderate degree of accuracy.

A Comparative Analysis of MicroRNA Expression in Mild, Moderate, and Severe COVID-19: Insights from Urine, Serum, and Nasopharyngeal Samples

COVID-19, caused by the SARS-CoV-2 virus, manifests with a wide range of clinical symptoms that vary from mild respiratory issues to severe respiratory distress. To effectively manage and predict the outcomes of the disease, it is important to understand the molecular mechanisms underlying its severity. This study focuses on analyzing and comparing the expression patterns of microRNAs (miRNAs) in serum, urine, and nasopharyngeal samples from patients with mild, moderate, and severe COVID-19. The aim is to identify potential associations with disease progression and discover suitable markers for diagnosis and prognosis. Our findings indicate the consistent upregulation of miR-21, miR-146a, and miR-155 in urine, serum, and nasopharyngeal samples from patients with mild COVID-19. In moderate cases, there were more significant changes in miRNA expression compared to mild cases. Specifically, miR-let-7 demonstrated upregulation, while miR-146b exhibited downregulation. The most notable alterations in miRNA expression profiles were observed in severe COVID-19 cases, with a significant upregulation of miR-223. Moreover, our analysis using Receiver-operating characteristic (ROC) curves demonstrated that miR-155, miR-let-7, and miR-223 exhibited high sensitivity and specificity, suggesting their potential as biomarkers for distinguishing COVID-19 patients from healthy individuals. Overall, this comparative analysis revealed distinct patterns in miRNA expression. The overlapping expression patterns of miRNAs in urine, serum, and nasopharyngeal samples suggest their potential utility in discriminating disease status.

TGF-β1 Inhibition of ACE2 Mediated by miRNA Uncovers Novel Mechanism of SARS-CoV-2 Pathogenesis

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for COVID-19, utilizes receptor binding domain (RBD) of spike glycoprotein to interact with angiotensin (Ang)-converting enzyme 2 (ACE2). Altering ACE2 levels may affect entry of SARS-CoV-2 and recovery from COVID-19. Decreased cell surface density of ACE2 leads to increased local levels of Ang II and may contribute to mortality resulting from acute lung injury and fibrosis during COVID-19. Studies published early during the COVID-19 pandemic reported that people with cystic fibrosis (PwCF) had milder symptoms, compared to people without CF. This finding was attributed to elevated ACE2 levels and/or treatment with the high efficiency CFTR modulators. Subsequent studies did not confirm these findings reporting variable effects of CFTR gene mutations on ACE2 levels. Transforming growth factor (TGF)-β signaling is essential during SARS-CoV-2 infection and dominates the chronic immune response in severe COVID-19, leading to pulmonary fibrosis. TGF-β1 is a gene modifier associated with more severe lung disease in PwCF but its effects on the COVID-19 course in PwCF is unknown. To understand whether TGF-β1 affects ACE2 levels in the airway, we examined miRNAs and their gene targets affecting SARS-CoV-2 pathogenesis in response to TGF-β1. Small RNAseq and micro(mi)RNA profiling identified pathways uniquely affected by TGF-β1, including those associated with SARS-CoV-2 invasion, replication, and the host immune responses. TGF-β1 inhibited ACE2 expression by miR-136-3p and miR-369-5p mediated mechanism in CF and non-CF bronchial epithelial cells. ACE2 levels were higher in two bronchial epithelial cell models expressing the most common CF-causing mutation in CFTR gene F508del, compared to controls without the mutation. After TGF-β1 treatment, ACE2 protein levels were still higher in CF, compared to non-CF cells. TGF-β1 prevented the modulator-mediated rescue of F508del-CFTR function while the modulators did not prevent the TGF-β1 inhibition of ACE2 levels. Finally, TGF-β1 reduced the interaction between ACE2 and the recombinant spike RBD by lowering ACE2 levels and its binding to RBD. Our data demonstrate novel mechanism whereby TGF-β1 inhibition of ACE2 in CF and non-CF bronchial epithelial cells may modulate SARS-CoV-2 pathogenicity and COVID-19 severity. By reducing ACE2 levels, TGF-β1 may decrease entry of SARS-CoV-2 into the host cells while hindering the recovery from COVID-19 due to loss of the anti-inflammatory and regenerative effects of ACE2. The above outcomes may be modulated by other, miRNA-mediated effects exerted by TGF-β1 on the host immune responses, leading to a complex and yet incompletely understood circuitry.

Circulating microRNA profile in response to remdesivir treatment in coronavirus disease 2019 (COVID-19) patients

Coronavirus disease 2019 (COVID-19), a serious infectious disease caused by the recently discovered severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused a major global health crisis. Although no specific antiviral drugs have been proven to be fully effective against COVID-19, remdesivir (GS-5734), a nucleoside analogue prodrug, has shown beneficial effects when used to treat severe hospitalized COVID-19 cases. The molecular mechanism underlying this beneficial therapeutic effect is still vaguely understood. In this study, we assessed the effect of remdesivir treatment on the pattern of circulating miRNAs in the plasma of COVID-19 patients, which was analyzed using MiRCURY LNA miRNA miRNome qPCR Panels and confirmed by quantitative real-time RT-PCR (qRT-PCR). The results revealed that remdesivir treatment can restore the levels of miRNAs that are upregulated in COVID-19 patients to the range observed in healthy subjects. Bioinformatics analysis revealed that these miRNAs are involved in diverse biological processes, including the transforming growth factor beta (TGF-β), hippo, P53, mucin-type O-glycan biosynthesis, and glycosaminoglycan biosynthesis signaling pathways. On the other hand, three miRNAs (hsa-miR-7-5p, hsa-miR-10b-5p, and hsa-miR-130b-3p) were found to be upregulated in patients receiving remdesivir treatment and in patients who experienced natural remission. These upregulated miRNAs could serve as biomarkers of COVID-19 remission. This study highlights that the therapeutic potential of remdesivir involves alteration of certain miRNA-regulated biological processes. Targeting of these miRNAs should therefore be considered for future COVID-19 treatment strategies.

MicroRNA (miRNA) Complexity in Alzheimer's Disease (AD)

AD is a complex, progressive, age-related neurodegenerative disorder representing the most common cause of senile dementia and neurological dysfunction in our elderly domestic population. The widely observed heterogeneity of AD is a reflection of the complexity of the AD process itself and the altered molecular-genetic mechanisms operating in the diseased human brain and CNS. One of the key players in this complex regulation of gene expression in human pathological neurobiology are microRNAs (miRNAs) that, through their actions, shape the transcriptome of brain cells that normally associate with very high rates of genetic activity, gene transcription and messenger RNA (mRNA) generation. The analysis of miRNA populations and the characterization of their abundance, speciation and complexity can further provide valuable clues to our molecular-genetic understanding of the AD process, especially in the sporadic forms of this common brain disorder. Current in-depth analyses of high-quality AD and age- and gender-matched control brain tissues are providing pathophysiological miRNA-based signatures of AD that can serve as a basis for expanding our mechanistic understanding of this disorder and the future design of miRNA- and related RNA-based therapeutics. This focused review will consolidate the findings from multiple laboratories as to which are the most abundant miRNA species, both free and exosome-bound in the human brain and CNS, which miRNA species appear to be the most prominently affected by the AD process and review recent developments and advancements in our understanding of the complexity of miRNA signaling in the hippocampal CA1 region of AD-affected brains.

Differentially-regulated miRNAs in COVID-19: A systematic review

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is responsible for coronavirus disease of 2019 (COVID-19) that infected more than 760 million people worldwide with over 6.8 million deaths to date. COVID-19 is one of the most challenging diseases of our times due to the nature of its spread, its effect on multiple organs, and an inability to predict disease prognosis, ranging from being completely asymptomatic to death. Upon infection, SARS-CoV-2 alters the host immune response by changing host-transcriptional machinery. MicroRNAs (miRNAs) are regarded as post-transcriptional regulators of gene expression that can be perturbed by invading viruses. Several in vitro and in vivo studies have reported such dysregulation of host miRNA expression upon SARS-CoV-2 infection. Some of this could occur as an anti-viral response of the host to the viral infection. Viruses themselves can counteract that response by mounting their own pro-viral response that facilitates virus infection, an aspect which may cause pathogenesis. Thus, miRNAs could serve as possible disease biomarkers in infected people. In the current review, we have summarised and analysed the existing data about miRNA dysregulation in patients infected with SARS-CoV-2 to determine their concordance between studies, and identified those that could serve as potential biomarkers during infection, disease progression, and death, even in people with other co-morbidities. Having such biomarkers can be vital in not only predicting COVID-19 prognosis, but also the development of novel miRNA-based anti-virals and therapeutics which can become invaluable in case of the emergence of new viral variants with pandemic potential in the future.

SARS-CoV-2 Transplacental Transmission: A Rare Occurrence? An Overview of the Protective Role of the Placenta

The outbreak of the coronavirus disease 2019 (COVID-19) pandemic, caused by novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in a global public health crisis, causing substantial concern especially to the pregnant population. Pregnant women infected with SARS-CoV-2 are at greater risk of devastating pregnancy complications such as premature delivery and stillbirth. Irrespective of the emerging reported cases of neonatal COVID-19, reassuringly, confirmatory evidence of vertical transmission is still lacking. The protective role of the placenta in limiting in utero spread of virus to the developing fetus is intriguing. The short- and long-term impact of maternal COVID-19 infection in the newborn remains an unresolved question. In this review, we explore the recent evidence of SARS-CoV-2 vertical transmission, cell-entry pathways, placental responses towards SARS-CoV-2 infection, and its potential effects on the offspring. We further discuss how the placenta serves as a defensive front against SARS-CoV-2 by exerting various cellular and molecular defense pathways. A better understanding of the placental barrier, immune defense, and modulation strategies involved in restricting transplacental transmission may provide valuable insights for future development of antiviral and immunomodulatory therapies to improve pregnancy outcomes.

Evaluation of the Relationship Between Serum miR-200b-3p and miR-214-3p Expression Levels with Soluble ACE2 and TMPRSS2 in COVID-19 Patients

Background

The emergence and rapid global spread of the coronavirus disease 2019 (COVID-19) has presented a significant global health challenge. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infects human host cells through the interaction of angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2), which serve as main regulators for viral entry. Specifically, ACE2 and TMPRSS2 genes are influenced by two microRNAs: miR-200b-3p and miR-214-3p, respectively. The objective of this study was to explore the association between the serum levels of miR-200b-3p and miR-214-3p and the presence of circulating ACE2 and TMPRSS2 in severe and non-severe cases of COVID-19.

Objectives

This study sought to examine the potential utility of microRNAs as biomarkers for assessing disease severity and progression. Additionally, the study aimed to elucidate the interplay between microRNAs and the ACE2 and TMPRSS2 proteins, which play crucial roles in facilitating SARS-CoV-2 viral entry and infection.

Methods

This practical-foundational study involved the collection of samples from 61 hospitalized patients with confirmed COVID-19 and 31 healthy individuals. Subsequently, the enzyme-linked immunosorbent assay (ELISA) technique was utilized to measure the concentrations of ACE2 and TMPRSS2 in the blood samples. Additionally, the expression levels of serum miR-200b-3p and miR-214-3p were analyzed using real-time polymerase chain reaction (PCR). The statistical analysis of the data was conducted using GraphPad Prism software (version 8.02) and SPSS software (version 19.0), ensuring the accurate interpretation of results.

Results

The findings revealed significant increases in the peripheral blood concentrations of ACE2 and TMPRSS2 in patients with non-severe COVID-19, compared to healthy individuals (P < 0.001 and P < 0.01, respectively). Similarly, patients with severe COVID-19 exhibited higher serum levels of ACE2 and TMPRSS2 than healthy subjects (P < 0.0001). Additionally, the serum levels of miR-200b-3p and miR-214-3p were decreased in both non-severe and severe COVID-19 patients, compared to healthy individuals (P < 0.01 and P < 0.0001, respectively). Moreover, a decrease in the serum levels of both miR-200b-3p and miR-214-3p was observed in patients with severe COVID-19, compared to those with non-severe cases (P < 0.001). Furthermore, this study identified a negative correlation between miR-200b-3p and ACE2 serum levels and between miR-214-3p and TMPRSS2 peripheral blood levels.

Conclusions

The above-mentioned findings suggest that miR-200b-3p and miR-214-3p might be potential biomarkers for disease severity and prognosis in COVID-19 patients.