To the tumor and beyond: Tales of a holistic miRNA delivery vehicle

Like the challenges and skepticism that faced the antibody therapeutics field over a decade ago, RNA therapeutics is facing the same. And, like the antibody therapeutics field, we are beginning to realize the clinical impact of RNA therapeutics amiss these challenges. This is most clearly highlighted with the recent approval of mRNA vaccines to prevent against SARS-CoV-2 and the first FDA approved RNAi drugs targeted to the liver. Unfortunately, RNA-based drugs targeted to cancer cells is lagging behind, even with countless years of work that has revealed the power of using RNAi for treating oncological diseases. Lack of success in this space is attributed to inability to deliver RNAi safely and effectively. A successful delivery agent requires multiple features. First, the agent must deliver the RNA specifically to the intended cells. Second, the agent must have a large therapeutic window, meaning that toxicity, if observed, should occur at doses that are orders of magnitude higher than the therapeutic dose. Third, if delivery of the RNA is by way of a specific ligand and receptor pair, as is the case herein, the RNA must successfully escape the endosome. Simply swelling the endosome is not enough if noncovalent interactions between the ligand and the receptor cannot be disrupted. Fourth, the RNA should include appropriate stabilizing modifications to increase intracellular half-life that will reduce dosing and cost. Through hard work and dedication in this space, we have come up with an inclusive, easily synthesized, intramolecular molecule that achieves all of these essential features. Moreover, the ligand used to achieve successful delivery is also being evaluated for imaging tumors localized in the central nervous system. Here, the challenges we face, the hurdles we have overcome, and the barriers that still remain to achieve success in revealing the clinical potential of miRNA as anti-cancer therapeutics will be presented.

Perinatal SARS-CoV-2 infection and vaccination: new insight

Cumulative data regardingCOVID-19 infection during pregnancy have demonstrated the ability of SARS-CoV-2 to infect the placenta. However, the mechanisms of SARS-CoV-2 placental viral entry are yet to be defined. SARS-CoV-2 infects cells by binding to the ACE2 receptor. However, SARS-CoV-2 cell entry also requires co-localization of spike protein cleavage by the serine protease TMPRSS2. However, the co-expression of ACE2 and TMPRSS2 in placental cells is debated, raising the question of whether potential non-canonical molecular mechanismsmay be involved in SARS-CoV-2 placental cells' viral entry. Although published data regarding the ability of the SARS-CoV- 2 to infect the fetus are contradicting, the placenta appears to be an immunological barrier to active SARS-CoV-2 infection and vertical transmission;however, the mechanism is unclear. Our experiments demonstrated the ability of the SARS-CoV-2 virus to directly infect the placenta and induce transcriptomic responses in COVID-positive mothers. These transcriptomic responses were characterized by differential expression of specific mRNAs and miRNAs associated with SARS-CoV-2 infection, with induction of specific placental miRNAs that can inhibit viral replication. Failure in such mechanisms may be associated with vertical transmission. Since the start of the COVID-19 pandemic, the COVID-19 mRNA vaccines have been widely used to reduce the morbidity and mortality of SARS-CoV-2 infection. Historically, non-live vaccines have not caused any harm to pregnant mothers;however, it is unclear whether our current understanding of the effects of non-live vaccines serves as a reliable precedent owing to the novel technology used to create these mRNA vaccines. Since there are no definitive data on the possible biodistribution of mRNA vaccines to the placenta, the likelihood of vaccine mRNA reaching the fetus remains uncertain. Little has been reported on the tissue localization of the lipid nanoparticles (LNPs) after intramuscular (IM) administration of the mRNA vaccine. The biodistribution of LNPs containing the mRNA vaccine has been investigated in animal models but not humans. In the murine model, the vaccine LNPs were rapidly disseminated to several organs, including the heart, liver, kidney, lung, and spleen, following IM administration. However, no traditional pharmacokinetic or biodistribution studies have been performed with the mRNA vaccines, including possible biodistribution to breast milk or the placenta.

MicroRNAs: The Master Regulators of the Breast Cancer Tumor Microenvironment

Breast cancer is the most commonly diagnosed cancer globally and is among the leading causes of cancer deaths worldwide. Breast cancer mortality rates are increasing due to delays in diagnosis, prognosis, and treatment caused by the coronavirus disease 2019 (COVID-19) pandemic. Identification and validation of blood-based breast cancer biomarkers for early detection is a top priority worldwide. MicroRNAs (miRNAs) show the potential to serve as breast cancer biomarkers. miRNAs are small, endogenously produced RNAs that regulate growth and development. However, oncogenic miRNAs also play a major role in tumor growth and can alter the tumor microenvironment (TME) in favor of cancer metastasis. The TME represents a complex network of diverse cancerous and noncancerous cell types, secretory proteins, growth factors, and miRNAs. Complex interactions within the TME can promote cancer progression and metastasis via multiple mechanisms, including oxidative stress, hypoxia, angiogenesis, lymphangiogenesis, and cancer stem cell regulation. Here, we decipher the mechanisms of miRNA regulating the TME, intending to use that knowledge to identify miRNAs as therapeutic targets in breast cancer and use miRNAs as blood-based biomarkers. © Springer Nature Singapore Pte Ltd. 2022.

NEI 2022 Abstracts

The proceedings contain 96 papers. The topics discussed include: practical pharmacotherapy for opioid use disorder in the age of fentanyl;can COVID-19 cause acute psychosis in pediatric patients? a case report;a survey of bullying experiences in a child and adolescent psychiatric clinic population;acute emergence of suicidal thoughts following Lemborexant initiation: an adverse reaction case report;assessing the unmet clinical need and opportunity for digital therapeutic intervention in schizophrenia: perspective from people with schizophrenia;rapid antidepressant effects and MADRS item improvements with AXS-05 (DEXTROMETHORPHAN-BUPROPION), an oral NMDA receptor antagonist in major depressive disorder: results from two randomized double-blind, controlled trials;targeting lncRNA NEAT1 impedes Alzheimers disease progression via MicroRNA-193a mediated CREB/BDNF and NRF2/NQO1 pathways;and impact of AXS-05 (DEXTROMETHORPHAN-BUPROPION), an Oral NMDA receptor antagonist, on Anhedonic symptoms in major depressive disorder.

Exosomal miR-145 and miR-885 regulate thrombosis in COVID-19.

We hypothesized that exosomal microRNAs (miRNAs) could be implied in the pathogenesis of thromboembolic complications in COVID-19. We isolated circulating exosomes from COVID-19 patients and then we divided our population in two arms based on the D-dimer level on hospital admission. We observed that exosomal miR-145 and miR-885 significantly correlate with D-Dimer levels. Moreover, we demonstrate that human endothelial cells express the main cofactors needed for SARS-CoV-2 internalization, including ACE2, TMPRSS2, and CD-147. Interestingly, human endothelial cells treated with serum from COVID-19 patients release significantly less miR-145 and miR-885, exhibit increased apoptosis, and display significantly impaired angiogenetic properties compared to cells treated with non-COVID-19 serum. Taken together, our data indicate that exosomal miR-145 and miR-885 are essential in modulating thromboembolic events in COVID-19. Significance Statement In this work, we demonstrate for the first time that two specific microRNA (namely miR-145 and miR-885) contained in circulating exosomes are functionally involved in thromboembolic events in COVID-19. Our findings are especially relevant to the general audience when considering the emerging prominence of post-acute sequelae of COVID-19 systemic manifestations known as Long-COVID.

Systems genetics identifies miRNA-mediated regulation of host response in COVID-19.

BACKGROUND: Individuals infected with SARS-CoV-2 vary greatly in their disease severity, ranging from asymptomatic infection to severe disease. The regulation of gene expression is an important mechanism in the host immune response and can modulate the outcome of the disease. miRNAs play important roles in post-transcriptional regulation with consequences on downstream molecular and cellular host immune response processes. The nature and magnitude of miRNA perturbations associated with blood phenotypes and intensive care unit (ICU) admission in COVID-19 are poorly understood. RESULTS: We combined multi-omics profiling-genotyping, miRNA and RNA expression, measured at the time of hospital admission soon after the onset of COVID-19 symptoms-with phenotypes from electronic health records to understand how miRNA expression contributes to variation in disease severity in a diverse cohort of 259 unvaccinated patients in Abu Dhabi, United Arab Emirates. We analyzed 62 clinical variables and expression levels of 632 miRNAs measured at admission and identified 97 miRNAs associated with 8 blood phenotypes significantly associated with later ICU admission. Integrative miRNA-mRNA cross-correlation analysis identified multiple miRNA-mRNA-blood endophenotype associations and revealed the effect of miR-143-3p on neutrophil count mediated by the expression of its target gene BCL2. We report 168 significant cis-miRNA expression quantitative trait loci, 57 of which implicate miRNAs associated with either ICU admission or a blood endophenotype. CONCLUSIONS: This systems genetics study has given rise to a genomic picture of the architecture of whole blood miRNAs in unvaccinated COVID-19 patients and pinpoints post-transcriptional regulation as a potential mechanism that impacts blood traits underlying COVID-19 severity. The results also highlight the impact of host genetic regulatory control of miRNA expression in early stages of COVID-19 disease.

Circulating Small RNA Profiling of Patients with Alveolar and Cystic Echinococcosis.

Alveolar (AE) and cystic (CE) echinococcosis are two parasitic diseases caused by the tapeworms Echinococcus multilocularis and E. granulosus sensu lato (s. l.), respectively. Currently, AE and CE are mainly diagnosed by means of imaging techniques, serology, and clinical and epidemiological data. However, no viability markers that indicate parasite state during infection are available. Extracellular small RNAs (sRNAs) are short non-coding RNAs that can be secreted by cells through association with extracellular vesicles, proteins, or lipoproteins. Circulating sRNAs can show altered expression in pathological states; hence, they are intensively studied as biomarkers for several diseases. Here, we profiled the sRNA transcriptomes of AE and CE patients to identify novel biomarkers to aid in medical decisions when current diagnostic procedures are inconclusive. For this, endogenous and parasitic sRNAs were analyzed by sRNA sequencing in serum from disease negative, positive, and treated patients and patients harboring a non-parasitic lesion. Consequently, 20 differentially expressed sRNAs associated with AE, CE, and/or non-parasitic lesion were identified. Our results represent an in-depth characterization of the effect E. multilocularis and E. granulosus s. l. exert on the extracellular sRNA landscape in human infections and provide a set of novel candidate biomarkers for both AE and CE detection.

Impact of COVID-19 on cognitive change

We hypothesize that cognitive impairment in humans after COVID-19 is due to a change in the epigenetic regulation of brain neurons due to the activation of retroelements under the influence of SARS-CoV-2 virus. In order to confirm the role of transposons in changing the functioning of the brain in patients with COVID-19, the scientific literature and the results of meta-analyses over the past 3 years were studied. As a result, we found that SARS-CoV-2 affects the brain not only through its direct effect, induction of inflammation and coagulopathy, but also through the activation of retroelements, the transcripts of which are processed into microRNAs. This is reflected in changes in the epigenetic regulation of genes in brain neurons, which is reflected in cognitive functions. The mechanisms of integration of the cDNA of SARS-CoV-2 virus into the human genome with the help of retroelement enzymes are described, which is reflected in the development of long-term changes in cognitive functions after COVID-19.

Deregulated miRNA expression is associated with endothelial dysfunction in post-mortem lung biopsies of COVID-19 patients.

MicroRNAs (miRNAs) are critical modulators of endothelial homeostasis, which highlights their involvement in vascular diseases, including the ones caused by virus infections. Our main objective was to identify miRNAs involved in the endothelial function and determine their expression in post-mortem lung biopsies of COVID-19 patients with severe respiratory injuries and thrombotic events. Based on functional enrichment analysis, miR-26a-5p, miR-29b-3p, and miR-34a-5p were identified as regulators of mRNA targets involved in endothelial, and inflammatory signaling pathways as well as in viral diseases. A miRNA/mRNA network, constructed based on protein-protein interactions of the miRNA targets and the inflammatory biomarkers characterized in the patients, revealed a close interconnection of these miRNAs with relevance to the endothelial activation/dysfunction. Reduced expression levels of selected miRNAs were observed in the lung biopsies of COVID-19 patients (n=9) compared to the Controls (n=10)(P<0.01-0.0001). MiR-26a-5p and miR-29b-3p presented the best power to discriminate these groups (AUC=0.8286, and AUC=0.8125, respectively). The correlation analysis of the miRNAs with inflammatory biomarkers in the COVID-19 patients was significant for miR-26a-5p [IL-6 (r2=0.5414), and ICAM-1(r2=0.5624)], and miR-29b-3p [IL-4 (r2=0.8332), and IL-8 (r2=0.2654)]. Altogether, these findings demonstrate the relevance and the non-random involvement of miR-26a-5p, miR-29b-3p, and miR-34a-5p in endothelial dysfunction and inflammatory response in patients with SARS-CoV-2 infection and the occurrence of severe lung injury and immunothrombosis.

Prediction models based on miRNA-disease relationship: Diagnostic relevance to multiple diseases including COVID-19.

BACKGROUND: Small, non-coding microRNAs, usually of 20-25 nucleotides, are known to regulate the post-transcriptional gene expression, which has a significant role in human biological processes, including immune-biogenesis, homeostasis and infection control as differential expression of such miRNAs is responsible for fine-tuning the organismic development. METHODS: A search of bibliographic databases was carried out with a focused question on microRNA-Disease Prediction. A deductive qualitative content analysis approach was further employed to assess the research's overall outcomes, review articles on prediction tools in miRNA-Diseases, and analyse the interventions. RESULTS: Diagnosis and therapeutics of diseases and miRNA prediction methods hold importance in identifying the regulatory mechanisms. Collections of efficient miRNA prediction methods to identify miRNA-mRNA-disease regulatory relationships have been presented through this review, consolidating the potential of miRNAs as a diagnostic and prognostic biomarker of multiple diseases, including COVID-19. CONCLUSIONS: The role of miRNA in the aetiology and pathogenesis of wide-range of pathologies, including viral, bacterial to chronic diseases such as cancer, is quite feasible through the modern tools in bioinformatics which has been elaborated focusing upon miRNA-disease prediction methods and their application potential establishing miRNAs as a robust and reliable biomarker in clinico-medical studies.

CBD Treatment Improves Fatal Inflammatory Response Exhibited in SEB-Induced ARDS

The novel SARS-CoV-2 virus known to cause the COVID-19 outbreak has resulted in a global healthcare crisis that has persisted the past 3 years. Thus, understanding the mechanisms underlying this disease are vital at this time. While there are issues of research infrastructure to handle the virus and because of the refractoriness of rodents to this disease, the availability of these tools is still limited. The cytokine storm and fatality presented in patients with severe COVID-19 can be mimicked with Staphylococcal enterotoxin B (SEB)-induced Acute Respiratory Distress Syndrome (ARDS). Within ~7 days, the survival rate drops to 0% for C3H/HeJ mice exposed to a dual dose of SEB. In this study, we administered cannabidiol (CBD) intraperitoneally for 3 days pre- and post-SEB dosing and found that the clinical outcomes improved significantly. Initial evaluation of scRNASeq data from lungs comparing naive to SEB-induced ARDS mice illustrated an increase in infiltrating immune cells, and a loss in pulmonary epithelial cells in the latter group. When evaluating the effect of CBD treatment on SEB-induced ARDS, we were able to demonstrate that CBD reduced the macrophage population. To characterize the mechanism by which CBD treatment ameliorated the inflammatory response, we found that CBD treated mice had significant reduction in infiltrating immune cells and alveolar thickening. This same histology and infiltration is presented in ARDS. MicroRNA expression analysis showed a significant increase in the expression mmu-miR-298-5p and mmu-miR- 566 with CBD treatment. Ingenuity Pathway Analysis (IPA) indicated that the dysregulated miRNAs were also implicated in pathways associated with macrophage activation, respiratory disease and inflammation, interferon stimulated genes, as well as genes which have been upregulated in the disease state of this model. These targets include but are not limited to Cebpb, Efhd2, Stat3, Socs3, Cxcl5, Gbp2, and Birc3. This finding offers insights for the development of preventive and therapeutic strategies in the treatment of ARDS, including that induced in COVID-19. Supported by NIH grants P01AT003961, P20GM103641, R01ES003961, R01AI129788, R01AI123947, R01AI160896 to MN and PSN and K99GM147910 to KW.Copyright © 2023 The American Society for Biochemistry and Molecular Biology, Inc.

Inflammasome but Not Ifn-I/Iii Response Is Altered in Children with Long Covid

Background: Severe COVID-19 is less common in children than in adults. Increasing evidence show that distinct immune-pathological changes can persist weeks or months after SARS-CoV2 infection, leading to Long COVID (LC). We investigated the systemic type I/III interferon (IFN-I/III) and inflammation response in peripheral blood mononuclear cells (PBMCs) of children with and without LC symptoms. Method(s): Blood samples were collected from children attending Umberto I hospital of Rome, within 3-6 months after a SARS-CoV-2 positive test and from control children. RNA was extracted from PBMCs for determining the levels of IFN-I (IFN-Alpha2, -Beta, -Epsilon and -Omega), IFN-III (IFN-Lambda1-3), NLRP3 and IL-1beta genes, and miR-141 expression by quantitative RealTime-PCR assays, normalized to housekeeping GUS gene and RNU6B, respectively. Result(s): 28 participants (M 12.5y SD 3.0) with LC symptoms, 28 participants (M 11.8y SD 3.0) without LC symptoms and 18 children who've never had SARS-CoV- 2 infection (M 10.5y SD 3.1) were enrolled. Comparing the three study groups, we found reduced levels of IFN-Lambda1, IFN-Lambda2 and IFN-Lambda3 (p=0.006, p< 0.001, p=0.012, respectively;Kruskal-Wallis (KW) test) mRNA in patients who have had SARS-CoV-2 infection as opposed to control group, whereas transcript levels of IFN-Epsilon (p= 0.019;KW test) were increased in the former with respect to the latter group;as well, remaining IFN-I genes analyzed showed a tendency to be up-regulated. As far as NLRP3 and IL-1beta levels was concerned, these genes were increased in LC patients (p< 0.001 for both genes;KW test). Additionally, miR-141, which has been reported to regulate inflammasome response, was overexpressed in LC patients (p< 0.001;Mann-Whitney test). Conclusion(s): These results showed a decreased levels of IFN-III mRNAs and an overexpression of IFN-Epsilon in children after 3-6 months of SARS-CoV-2 infection regardless of development of LC symptoms, suggesting that SARSCoV- 2 could have caused dysregulation of IFN response through unknown mechanisms (e.g. epigenetic modifications). Also, we found an overexpression of miR-141, NLRP3 and IL-1beta mRNAs in LC patients, indicating that a prolonged activation of inflammasome pathways could be associated with the development of LC symptoms.

Plasma-derived exosomal miRNA as potential biomarker for diagnosis and prognosis of vector-borne diseases: A review.

Early disease diagnosis is critical for better management and treatment outcome of patients. Therefore, diagnostic methods should ideally be accurate, consistent, easy to perform at low cost and preferably non-invasive. In recent years, various biomarkers have been studied for the detection of cardiovascular diseases, cerebrovascular diseases, infectious diseases, diabetes mellitus and malignancies. Exosomal microRNA (miRNA) are small non-coding RNA molecules that influence gene expression after transcription. Previous studies have shown that these types of miRNAs can potentially be used as biomarkers for cancers of the breast and colon, as well as diffuse large B-cell lymphoma. It may also be used to indicate viral and bacterial infections, such as the human immunodeficiency virus (HIV), tuberculosis and hepatitis. However, its use in the diagnosis of vector-borne diseases is rather limited. Therefore, this review aims to introduce several miRNAs derived from exosomal plasma that may potentially serve as a disease biomarker due to the body's immune response, with special focus on the early detection of vector-borne diseases.

Systematic levels of IL-29 and microRNA185-5p were not associated with severe COVID-19 in the Iranian population.

BACKGROUND: Increased systematic pro-inflammatory cytokines is the main cause of the inflammatory conditions of the hospitalized severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infected patients. In this project, serum levels of IL-29 and whole blood levels of microRNA-185-5p (miR-185-5p) were evaluated in the hospitalized SARS-CoV-2 infected patients. METHODS: This project was performed on the 60 hospitalized SARS-CoV-2 infected patients and 60 healthy controls to evaluate IL-29 and miR185-5p expression levels. IL-29 expression was explored using enzyme linked immunoassay (ELISA), while miR185-5p was evaluated using Real-Time PCR techniques. RESULTS: The results demonstrated that neither IL-29 serum levels nor relative expressions of miR-185-5p were significantly different between patients and healthy controls. CONCLUSION: Due to the results that are presented here, systematic levels of IL-29 and miR-185-5p cannot be considered as the main risk factors for induction of inflammation in the hospitalized SARS-CoV-2 infected patients.

Exploration of Potential Biomarkers and Mechanisms for COVID-19 and Asthma Based on Microarray Analysis

Aims: The aim of this study is to investigate the potential mechanisms of coronavirus disease (COVID-19) and asthma comor-bidities.Methods: GSE147507 and GSE143303 datasets were obtained from the Gene Expression Omnibus (GEO) database, the differ-ential expressed genes (DEGs) were identified, and the overlapping DEGs were obtained by determining the DEG intersection between the two datasets. A series of analyses of the shared DEGs were performed, including enrichment analysis, protein -protein interaction (PPI) network construction, construction of transcription factor (TF)/microRNA (miRNA)-gene interaction networks, drug-gene and disease-gene interactions, and receiver operating characteristic curve (ROC) analysis.Results: A total of 135 overlapping DEGs were obtained by determining the DEGs intersection between the GSE147507 and GSE143303 datasets. These overlapped DEGs were significantly enriched in the regulation of DNA-templated transcription, initi-ation, clathrin-sculpted gamma-aminobutyric acid transport vesicle, DNA binding, and eight KEGG (kyoto encyclopedia of genes and genomes) pathways. The PPI network revealed that HSPA8, SRSF1, NDUFAB1, PTEN, CCT8, HIST1H2BK, HIST2H2BE, DLAT, EIF3G, and WAC, with high scores, were the hub genes. In addition, 65 TFs (transcription factors) and 369 miRNAs tar-geted overlapping DEGs. Finally, these overlapped DEGs were also related to other diseases, such as hyperglycemia, metabolic acidosis, and lung neoplasm, and the top 10 drugs with the most significant potential included lanatoside C, digoxin, GW-8510, doxorubicin, daunorubicin, proscillaridin, anisomycin, helveticoside, ouabain, and bisacodyl. The ROC analysis results shown that these hub genes had good diagnostic performance.Conclusions: HSPA8, SRSF1, NDUFAB1, PTEN, CCT8, HIST1H2BK, HIST2H2BE, DLAT, EIF3G, WAC, FOXC1, GATA2, hsa-miR-93-5p, and hsa-miR-17-5p may play vital roles in COVID-19 (corona virus disease-2019)/asthma comorbidity. Lanatoside C, digoxin, GW-8510, doxorubicin, daunorubicin, proscillaridin, anisomycin, helveticoside, ouabain, and bisacodyl may serve as drug targets against COVID-19/asthma comorbidity.

Nanopore single-molecule analysis of biomarkers: Providing possible clues to disease diagnosis

Biomarker detection has attracted increasing interest in recent years due to the minimally or non-invasive sampling process. Single entity analysis of biomarkers is expected to provide real-time and accurate biological information for early disease diagnosis and prognosis, which is critical to the effective disease treatment and is also important in personalized medicine. As an innovative single entity analysis method, nanopore sensing is a pioneering single-molecule detection technique that is widely used in analytical bioanalytical fields. In this review, we overview the recent progress of nanopore biomarker detection as new approaches to disease diagnosis. In highlighted studies, nanopore was focusing on detecting biomarkers of different categories of communicable and noncommunicable diseases, such as pandemic COVID-19, AIDS, cancers, neurologic diseases, etc. Various sensitive and selective nanopore detecting strategies for different types of biomarkers are summarized. In addition, the challenges, opportunities, and direction for future development of nanopore-based biomarker sensors are also discussed.Copyright © 2023 Elsevier B.V.

Thrombosis-related miR-16-5p predicts the disease severity in patients hospitalised for COVID-19

Introduction: SARS-CoV-2 tropism for the ACE2 receptor, along with the multifaceted inflammatory reaction, is likely to drive the generalized hypercoagulable state seen in patients with COVID-19. Methodology: Using the original bioinformatic workflow and network medicine approaches we reanalyzed four coronavirus-related expression datasets and performed co-expression analysis focused on thrombosis and ACE2 related genes. We identified microRNAs (miRNAs) which play role in ACE2-related thrombosis in coronavirus infection and further, we validated the expressions of those miRNAs in 79 hospitalized COVID-19 patients and 32 healthy volunteers by PCR and monitored miRNAs patterns during the acute phase of COVID-19, as well as the prognostic potential of these miRNAs as biomarkers. Result(s): We identified EGFR, HSP90AA1, APP, TP53, PTEN, UBC, FN1, ELAVL1 and CALM1 as regulatory genes which could play a pivotal role in COVID-19 related thrombosis. We also found miR-16-5p, miR-27a-3p, Let- 7b-5p and miR-155-5p as regulators in coagulation and thrombosis process. We observed in separate cohort of COVID-19 patients and healthy controls that (i) expression of miR-16-5p, miR-27a-3p and miR-155-5p increased during observation, compared to the baseline measurement;(ii) a low baseline miR-16-5p expression presents predictive utility in assessment of the hospital length of stay or death in follow-up as a composite endpoint (AUC: 0.810, 95% CI, 0.71-0.91, p<0.0001);(iii) low baseline expression of miR-16-5p and diabetes mellitus are independent predictors of increased length of stay or death according to a multivariate analysis (OR: 9.417;95% CI, 2.647-33.506;p=0.0005 and OR: 6.257;95% CI, 1.049- 37.316;p=0.044, respectively). Conclusion(s): This study enabled us to better characterize changes in gene expression and signaling pathways related to COVID-19 thrombosis. In this study we identified, characterized and validated miRNAs which could serve as novel, thrombosis-related biomarkers of the COVID-19, can be used for early stratification of patients and prediction of severity of infection development in an individual. (Figure Presented) .

Expression changes of circulating ACE2 regulating-microRNA profiles in patients with COVID-19 during hospitalisation

Background: Various miRNAs, as well as their target genes are involved in the complex pathophysiology of inflammation, immune response, coagulation and CVDs. Thus, they may be useful for diagnosis, prognosis and as a potential therapeutic strategy in multiple pathologies. Aim(s): According to our previously published bioinformatics analysis, we aimed to analyze the diagnostic and predictive utility of miRNAs regulating ACE2 network (miR-26b-5p, miR-10b-5p, miR-302c-5p, hsa-miR-200b-3p, hsa-miR-124-3p) in patients with COVID-19. Result(s): The expression levels of miR-26b-5p in COVID-19 patients were found lower at the baseline, 7 and 21-days after admission. compared to the healthy controls (p<0.0001 for all time points). Similarly, miR-10b-5p expression levels were lower at the baseline and 21-days post admission in COVID-19 patients when compared to the healthy individuals (p=0.001 in both time points). Moreover, expression levels of this miRNA were higher 7- days post-admission when compared to the baseline (p=0.003). According to the ROC curve analysis, low miR-200b-3p expression presents predictive utility in assessment of the hospital length of stay and/or death (AUC: 0.730, p=0.002). According to the multivariable logistic regression model, low delta miR-200p expression, together with diabetes mellitus (DM), are independent predictors of increased hospital length of stay and/or death (OR: 5.775;95% CI, 1.572-21.214;p=0.008 and OR: 4.888;95% CI, 1.001-23.858;p=0.050, respectively). Conclusion(s): This study enabled us to better characterize changes in gene expression and signaling pathways related to COVID-19 thrombosis. In this study we identified, characterized and validated miRNAs which could serve as novel, thrombosis-related biomarkers of the COVID-19, can be used for early stratification of patients and prediction of severity of infection development in an individual. (Figure Presented) .

In silico identification of potential miRNAs -mRNA inflammatory networks implicated in the pathogenesis of COVID-19

COVID-19 has been found to affect the expression profile of several mRNAs and miRNAs, leading to dysregulation of a number of signaling pathways, particularly those related to inflammatory responses. In the current study, a systematic biology procedure was used for the analysis of high-throughput expression data from blood specimens of COVID-19 and healthy individuals. Differentially expressed miRNAs in blood specimens of COVID-19 vs. healthy specimens were then identified to construct and analyze miRNA-mRNA networks and predict key miRNAs and genes in inflammatory pathways. Our results showed that 171 miRNAs were expressed as outliers in box plot and located in the critical areas according to our statistical analysis. Among them, 8 miRNAs, namely miR-1275, miR-4429, miR-4489, miR-6721-5p, miR-5010-5p, miR-7110-5p, miR-6804-5p and miR-6881-3p were found to affect expression of key genes in NF-KB, JAK/STAT and MAPK signaling pathways implicated in COVID-19 pathogenesis. In addition, our results predicted that 25 genes involved in above-mentioned inflammatory pathways were targeted not only by these 8 miRNAs but also by other obtained miRNAs (163 miRNAs). The results of the current in silico study represent candidate targets for further studies in COVID-19.Copyright © 2023 Elsevier B.V.