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

The potential of circulating microRNAs as novel diagnostic biomarkers of COVID-19: a systematic review and meta-analysis

INTRODUCTION

The COVID-19 pandemic has caused an unprecedented health threat globally, necessitating innovative and efficient diagnostic approaches for timely identification of infected individuals. Despite few emerging reports, the clinical utility of circulating microRNAs (miRNAs) in early and accurate diagnosis of COVID-19 is not well-evidenced. Hence, this meta-analysis aimed to explore the diagnostic potential of circulating miRNAs for COVID-19. The protocol for this study was officially recorded on PROSPERO under registration number CRD42023494959.

METHODS

Electronic databases including Embase, PubMed, Scopus, and other sources were exhaustively searched to recover studies published until 16th January, 2024. Pooled specificity, sensitivity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic ratio (DOR), positive predictive value (PPV), negative predictive value (NPV), and area under the curve (AUC) were computed from the metadata using Stata 14.0 software. Risk of bias appraisal of included articles was carried out using Review Manager (Rev-Man) 5.3 package through the modified QUADAS-2 tool. Subgroup, heterogeneity, meta-regression and sensitivity analyses were undertaken. Publication bias and clinical applicability were also evaluated via Deeks' funnel plot and Fagan nomogram (scattergram), respectively.

RESULT

A total of 43 studies from 13 eligible articles, involving 5175 participants (3281 COVID-19 patients and 1894 healthy controls), were analyzed. Our results depicted that miRNAs exhibit enhanced pooled specificity 0.91 (95% CI: 0.88-0.94), sensitivity 0.94 (95% CI: 0.91-0.96), DOR of 159 (95% CI: 87-288), and AUC values of 0.97 (95% CI: 0.95-0.98) with high pooled PPV 96% (95% CI: 94-97%) and NPV 88% (95% CI: 86-90%) values. Additionally, highest diagnostic capacity was observed in studies involving larger sample size (greater than 100) and those involving the African population, demonstrating consistent diagnostic effectiveness across various specimen types. Notably, a total of 12 distinct miRNAs were identified as suitable for both exclusion and confirmation of COVID-19 cases, denoting their potential clinical applicability.

CONCLUSION

Our study depicted that miRNAs show significantly high diagnostic accuracy in differentiating COVID-19 patients from healthy counterparts, suggesting their possible use as viable biomarkers. Nonetheless, thorough and wide-ranging longitudinal researches are necessary to confirm the clinical applicability of miRNAs in diagnosing COVID-19.

The roles played by hsa-miR-223-5p and mutations in the S gene of SARS-CoV-2 in COVID-19

BACKGROUND

Increased proinflammatory molecules are a main reason for severe symptoms in patients infected with SARS-CoV-2. This study evaluated mutations in the S gene of SARS-CoV-2 and the expression of hsa-miR-223-5p, interleukin 2 receptor α (IL-2Rα), and CCL16 chemokine in hospitalized SARS-CoV-2 infected patients.

DESIGN

This is a cross-sectional study.

METHODS

This study included 75 SARS-CoV-2-infected patients with severe symptoms and 75 age-sex-matched healthy controls. Real-time polymerase chain reaction techniques were used to evaluate the expression levels of hsa-miR-223-5p, IL-2Rα, and CCL16 chemokine. The Sanger technique was used to sequence the S gene of SARS-CoV-2 from positions 23,274 to 23,641.

RESULTS

The relative expression of hsa-miR-223-5p was significantly increased whereas that of IL-2Rα was significantly decreased in the SARS-CoV-2 infected patients. Two mutations were found in the S gene of SARS-CoV-2 at positions 23,403 (p.Asp23403Gly) and 23,525 (p.His23525Tyr) of the S gene of SARS-CoV-2.

CONCLUSION

Increased hsa-miR-223-5p may be a main cause for the downregulation of IL-2Rα, which is a main developer of T-regulatory lymphocytes. The mutations in the S gene of SARS-CoV-2-infected patients may affect immune responses to the molecule and alter the avidity of virus-human cell interactions.

Role of microRNAs in Immune Regulation with Translational and Clinical Applications

MicroRNAs (miRNAs) are 19-23 nucleotide long, evolutionarily conserved noncoding RNA molecules that regulate gene expression at the post-transcriptional level. In this review, involvement of miRNAs is summarized in the differentiation and function of immune cells, in anti-infective immune responses, immunodeficiencies and autoimmune diseases. Roles of miRNAs in anticancer immunity and in the transplantation of solid organs and hematopoietic stem cells are also discussed. Major focus is put on the translational clinical applications of miRNAs, including the establishment of noninvasive biomarkers for differential diagnosis and prediction of prognosis. Patient selection and response prediction to biological therapy is one of the most promising fields of application. Replacement or inhibition of miRNAs has enormous therapeutic potential, with constantly expanding possibilities. Although important challenges still await solutions, evaluation of miRNA fingerprints may contribute to an increasingly personalized management of immune dysregulation with a remarkable reduction in toxicity and treatment side effects. More detailed knowledge of the molecular effects of physical exercise and nutrition on the immune system may facilitate self-tailored lifestyle recommendations and advances in prevention.