MicroRNA-548 down-regulates host antiviral response via direct targeting of IFN-λ1

Advances in anti-EV-A71 drug development research

BACKGROUND

Enterovirus A71 (EV-A71) is capable of causing hand, foot and mouth disease (HFMD), which may lead to neurological sequelae and even death. As EV-A71 is resistant to environmental changes and mutates easily, there is still a lack of effective treatments or globally available vaccines.

AIM OF REVIEW

For more than 50 years since the HFMD epidemic, related drug research has been conducted. Progress in this area can promote the further application of existing potential drugs and develop more efficient and safe antiviral drugs, and provide useful reference for protecting the younger generation and maintaining public health security.

KEY SCIENTIFIC CONCEPTS OF REVIEW

At present, researchers have identified hundreds of EV-A71 inhibitors based on screening repurposed drugs, targeted structural design, and rational modification of previously effective drugs as the main development strategies. This review systematically introduces the current potential drugs to inhibit EV-A71 infection, including viral inhibitors targeting key sites such as the viral capsid, RNA-dependent RNA polymerase (RdRp), 2C protein, internal ribosome entry site (IRES), 3C proteinase (3Cpro), and 2A proteinase (2Apro), starting from each stage of the viral life cycle. Meanwhile, the progress of host-targeting antiviral drugs and their development are summarized in terms of regulating host immunity, inhibiting autophagy or apoptosis, and regulating the cellular redox environment. In addition, the current clinical methods for the prevention and treatment of HFMD are summarized and discussed with the aim of providing support and recommendations for the treatment of enterovirus infections including EV-A71.

MicroRNAs in infectious diseases: potential diagnostic biomarkers and therapeutic targets

MicroRNAs (miRNAs) are conserved, short, non-coding RNAs that play a crucial role in the post-transcriptional regulation of gene expression. They have been implicated in the pathogenesis of cancer and neurological, cardiovascular, and autoimmune diseases. Several recent studies have suggested that miRNAs are key players in regulating the differentiation, maturation, and activation of immune cells, thereby influencing the host immune response to infection. The resultant upregulation or downregulation of miRNAs from infection influences the protein expression of genes responsible for the immune response and can determine the risk of disease progression. Recently, miRNAs have been explored as diagnostic biomarkers and therapeutic targets in various infectious diseases. This review summarizes our current understanding of the role of miRNAs during viral, fungal, bacterial, and parasitic infections from a clinical perspective, including critical functional mechanisms and implications for their potential use as biomarkers and therapeutic targets.

miR-548c-3p targets TRIM22 to attenuate the Peg–IFN–α therapeutic efficacy in HBeAg-positive patients with chronic hepatitis B

Chronic hepatitis B (CHB) patients treated with interferon shows encouraging results. However, its clinical efficacy is limited by significant individual differences in treatment responses. We identified an interferon-inducible effector, TRIM22, as the likely causal target of such differential responses. We found that TRIM22 was highly expressed in interferon-responsive patients and negatively correlated with HBV DNA and HBeAg serum levels. Stable cells overexpressing TRIM22 carried significantly less HBsAg, HBeAg, and HBV DNA, and cells with knocked-down TRIM22 by shRNA displayed higher levels of these markers than controls. Integrated bioinformatics analysis and subsequent experiments revealed that TRIM22 overexpression significantly increased the supernatant levels of IL-1β and IL-8, two important cytokines of NOD2/NF-κB pathway involved in interferon-induced antiviral activities. We identified three candidate microRNAs binding to 3'UTR of TRIM22 at various locations through typical imperfect paring using the TargetScan program. MiR-548c-3p appeared to be highly expressed, while the TRIM22 level was low in the suboptimal response group of CHB patients. The Luciferase reporter assay revealed an interaction between miR-548c-3p and the 3'UTR of TRIM22, leading to a controlled suppression of TRIM22 endogenous expression. This resulted in interferon's substantially weakened therapeutic efficacy, as indicated by the elevation of the serum levels of HBsAg, HBeAg and HBV DNA in miR-548c-3p-transfected HepAD38 cells. Our study demonstrated that a particular miR-548c-3p is the key negative regulator of TRIM22 in CHB patients with a weak response to interferon treatment, providing a novel marker and target in interferon-α therapy evaluation.

Association Between Serum MicroRNAs and Abdominal Aortic Aneurysm Diagnosis and Growth

OBJECTIVE

This study aimed to examine the association between serum microRNAs (miRNAs) and diagnosis and growth of abdominal aortic aneurysm (AAA), and to test their diagnostic and prognostic value.

METHODS

The expression levels of 800 miRNA tags were assessed in 108 patients with AAA, 12 age and sex matched healthy controls (HCs), and 12 patients with peripheral artery disease (PAD) using NanoString technology. Findings were assessed in an independent sample of 66 patients with AAA and 29 age and sex matched HCs by reverse transcriptase polymerase chain reaction. AAA growth was assessed by a median of three (interquartile range [IQR] 2, 3) repeat ultrasound scans over a median follow up of 1.1 (IQR 1.0, 2.0) years. The association between the miRNA and AAA diagnosis and growth was examined by regression and linear mixed effects analyses. The diagnostic and prognostic potential of the miRNAs were examined using area under the receiver operator characteristic curve (AUC), net re-classification index (NRI), and Cox hazard analyses.

RESULTS

In comparison with HCs, a model combining clinical risk factors, let-7b-5p and miR-548n had an AUC of 98.0% (95% confidence interval [CI] 95.6 - 100.0; p = .003) for diagnosing AAA, which was a significant improvement over clinical risk factors alone (NRI 1.74; 95% CI 1.61 - 1.87; p < .001). Compared with PAD, a model combining clinical risk factors and miR-548n had an AUC of 99.6% (95% CI 98.9 - 100.0, p = .037) for diagnosing AAA, which was a significant improvement over clinical risk factors alone (NRI 1.79, 95% CI 1.68 - 1.91; p < .001). In the longitudinal cohort, none of the miRNAs were able to predict the likelihood of reaching surgical threshold diameter better than clinical risk factors alone.

CONCLUSION

Serum let-7b-5p and miR548n significantly improved the ability to diagnose AAA. None of the miRNAs had independent prognosis value in predicting AAA growth.

Association of Dengue Virus Serotypes 1&2 with Severe Dengue Having Deletions in Their 3′Untranslated Regions (3′UTRs)

Dengue virus infections are recorded as hyper-endemic in many countries, including India. Research pertaining to the reasons for frequent outbreaks and severe dengue is ongoing. Hyderabad city, India, has been recorded as a ‘hotspot’ for dengue virus infections. Dengue virus strains circulating over the past few years in Hyderabad city have been characterized at the molecular level to analyze the serotype/genotypes; 3′UTRs were further amplified and sequenced. The disease severity in patients infected with dengue virus strains with complete and 3′UTR deletion mutants was analyzed. Genotype I of the serotype 1 replaced genotype III, which has been circulating over the past few years in this region. Coincidentally, the number of dengue virus infections significantly increased in this region during the study period. Nucleotide sequence analysis suggested twenty-two and eight nucleotide deletions in the 3′UTR of DENV-1. The eight nucleotide deletions observed in the case of DENV-1 3′UTR were the first reported in this instance. A 50 nucleotide deletion was identified in the case of the serotype DENV-2. Importantly, these deletion mutants were found to cause severe dengue, even though they were found to be replication incompetent. This study emphasized the role of dengue virus 3′UTRs on severe dengue and emerging outbreaks.

Exosomes Released by Influenza-Virus-Infected Cells Carry Factors Capable of Suppressing Immune Defense Genes in Naïve Cells

Background: Exosomes are involved in intercellular communication and can transfer regulatory molecules between cells. Consequently, they can participate in host immune response regulation. For the influenza A virus (IAV), there is very limited information on changes in exosome composition during cell infection shedding light on the potential role of these extracellular membrane vesicles. Thus, the aim of our work was to study changes in exosomal composition following IAV infection of cells, as well as to evaluate their effect on uninfected cells. Methods: To characterize changes in the composition of cellular miRNAs and mRNAs of exosomes during IAV infection of A549 cells, NGS was used, as well as PCR to identify viral genes. Naïve A549 cells were stimulated with infected-cell-secreted exosomes for studying their activity. Changes in the expression of genes associated with the cell's immune response were shown using PCR. The effect of exosomes on IAV replication was shown in MDCK cells using In-Cell ELISA and PCR of the supernatants. Results: A change in the miRNA composition (miR-21-3p, miR-26a-5p, miR-23a-5p, miR-548c-5p) and mRNA composition (RPL13A, MKNK2, TRIB3) of exosomes under the influence of the IAV was shown. Many RNAs were involved in the regulation of the immune response of the cell, mainly by suppressing it. After exosome stimulation of naïve cells, a significant decrease in the expression of genes involved in the immune response was shown (RIG1, IFIT1, MDA5, COX2, NFκB, AnxA1, PKR, IL6, IL18). When infecting MDCK cells, a significant decrease in nucleoprotein levels was observed in the presence of exosomes secreted by mock-infected cells. Viral levels in supernatants also decreased. Conclusions: Exosomes secreted by IAV-infected cells could reduce the immune response of neighboring intact cells, leading to more effective IAV replication. This may be associated both with regulatory functions of cellular miRNAs and mRNAs carried by exosomes, or with the presence of viral mRNAs encoding proteins with an immunosuppressive function.

Cytokines and microRNAs in SARS-CoV-2: What do we know?

The coronavirus disease 2019 (COVID-19) pandemic constitutes a global health emergency. Currently, there are no completely effective therapeutic medications for the management of this outbreak. The cytokine storm is a hyperinflammatory medical condition due to excessive and uncontrolled release of pro-inflammatory cytokines in patients suffering from severe COVID-19, leading to the development of acute respiratory distress syndrome (ARDS) and multiple organ dysfunction syndrome (MODS) and even mortality. Understanding the pathophysiology of COVID-19 can be helpful for the treatment of patients. Evidence suggests that the levels of tumor necrosis factor alpha (TNF-α) and interleukin (IL)-1 and IL-6 are dramatically different between mild and severe patients, so they may be important contributors to the cytokine storm. Several serum markers can be predictors for the cytokine storm. This review discusses the cytokines involved in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, focusing on interferons (IFNs) and ILs, and whether they can be used in COVID-19 treatment. Moreover, we highlight several microRNAs that are involved in these cytokines and their role in the cytokine storm caused by COVID-19.

SP1/miR-92a-1-5p/SOCS5: A novel regulatory axis in feline panleukopenia virus replication

MicroRNAs (miRNAs) are vital post-transcriptional regulators that participate in host-pathogen interactions by modulating the expression of cellular factors. Previous studies have demonstrated that feline panleukopenia virus (FPV) alters miRNA expression levels within host cells. However, the relationship between FPV replication and host miRNAs remains unclear. Here, we demonstrated that FPV infection significantly altered cellular miR-92a-1-5p expression in F81 cells by upregulating the expression of specificity protein 1 (SP1). Furthermore, we observed that miR-92a-1-5p enhanced interferon (IFN-α/β) expression by targeting the suppressors of cytokine signaling 5 (SOCS5) that negatively regulates NF-κB signaling and inhibits FPV replication in host cells. These findings revealed that miR-92a-1-5p plays a crucial role in host defense against FPV infection.

Roles of Non-Coding RNAs in Virus-Host Interaction About Pathogenesis of Hand-Foot-Mouth Disease

Noncoding RNAs (ncRNAs) represent the largest and main transcriptome products and play various roles in the biological activity of cells and pathological processes. Accumulating evidence shows that microRNA (miRNA), long non-coding RNA (lncRNA), and circular RNA (circRNA) are important ncRNAs that play vital regulatory roles during viral infection. Hand-foot-mouth disease (HFMD) virus causes hand-foot-mouth disease, and is also associated with various serious complications and high mortality. However, there is currently no effective treatment. In this review, we focus on advances in the understanding of the modulatory role of ncRNAs during HFMD virus infection. Specifically, we discuss the generation, classification, and regulatory mechanisms of miRNA, lncRNA, and circRNA in the interaction between virus and host, with a particular focus on their influence with viral replication and infection. Analysis of these underlying mechanisms can help provide a foundation for the development of ncRNA-based antiviral therapies.

Single cell gene expression profiling of nasal ciliated cells reveals distinctive biological processes related to epigenetic mechanisms in patients with severe COVID-19

Objective

To explore the molecular processes associated with cellular regulatory programs in patients with COVID-19, including gene activation or repression mediated by epigenetic mechanisms. We hypothesized that a comprehensive gene expression profiling of nasopharyngeal epithelial cells might expand our understanding of the pathogenic mechanisms of severe COVID-19.

Methods

We used single-cell RNA sequencing (scRNAseq) profiling of ciliated cells (n = 12,725) from healthy controls (SARS-CoV-2 negative n = 13) and patients with mild/moderate (n = 13) and severe (n = 14) COVID-19. ScRNAseq data at the patient level were used to perform gene set and pathway enrichment analyses. We prioritized candidate miRNA-target interactions and epigenetic mechanisms.

Results

We found that mild/moderate COVID-19 compared to healthy controls had upregulation of gene expression signatures associated with mitochondrial function, misfolded proteins, and membrane permeability.

In addition, we found that compared to mild/moderate disease, severe COVID-19 had downregulation of epigenetic mechanisms, including DNA and histone H3K4 methylation and chromatin remodelling regulation. Furthermore, we found 11-ranked miRNAs that may explain miRNA-dependent regulation of histone methylation, some of which share seed sequences with SARS-CoV-2 miRNAs.

Conclusion

Our results may provide novel insights into the epigenetic mechanisms mediating the clinical course of SARS-CoV-2 infection.

Potential of MicroRNAs As Biomarkers and Therapeutic Targets in Respiratory Viruses: A Literature Review

MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression through recognition of cognate sequences and interference of transcriptional, translational, or epigenetic processes. Hundreds of miRNA genes have been found in diverse viruses, and many of these are phylogenetically conserved. Respiratory viruses are the most frequent causative agents of disease in humans, with a significant impact on morbidity and mortality worldwide. Recently, the role of miRNAs in respiratory viral gene regulation, as well as host gene regulation during disease progression, has become a field of interest. This review highlighted the importance of various miRNAs and their potential role in fighting with respiratory viruses as therapeutic molecules with a focus on COVID-19.

Role of Non-Coding RNA in Neurological Complications Associated With Enterovirus 71

Enterovirus 71 (EV71) is the main pathogenic virus that causes hand, foot, and mouth disease (HFMD). Studies have reported that EV71-induced infections including aseptic meningitis, acute flaccid paralysis, and even neurogenic pulmonary edema, can progress to severe neurological complications in infants, young children, and the immunosuppressed population. However, the mechanisms through which EV71 causes neurological diseases have not been fully explored. Non-coding RNAs (ncRNAs), are RNAs that do not code for proteins, play a key role in biological processes and disease development associated with EV71. In this review, we summarized recent advances concerning the impacts of ncRNAs on neurological diseases caused by interaction between EV71 and host, revealing the potential role of ncRNAs in pathogenesis, diagnosis and treatment of EV71-induced neurological complications.

MicroRNA548ac expression level in relation to BDCAF scored Behçet’s disease activity and history of treatment response

Background

Behçet’s disease gives a challenge to be diagnosed and followed up due to lack of specific biomarkers. MicroRNAs showed relations to different disease states including immunological and inflammatory illnesses. In this study, we are estimating microRNA548ac levels for the first time to be tested in the disease to see if there is a link to disease activity and if microRNA548ac can be used as a biomarker for activity or remission and prognosis of Behçet’s disease. MicroRNA548ac has been shown to have a role in autoimmunity and some inflammatory conditions. Blood samples were taken from patients to measure white blood cells expression of microRNA548ac, and compared to its expression in healthy subjects, disease activity was assessed by usage of Behçet’s Disease Current Activity Form (BDCAF).

Results

MicroRNA548ac expression decreased but not significantly with increased Behçet’s disease activity, and expression was having a significant positive correlation with increased treatment response history.

Conclusions

MicroRNA548ac appeared not to be related to disease activity which needs confirmation in further studies, but it may predict response to treatment so that patients having higher expression of microRNA548ac may have a better response to treatment. Here, microRNA548ac could be used as a disease biomarker for disease prognosis.

Host Genetic Associations with Salivary Microbiome in Oral Cancer

Despite the growing recognition of a host genetic effect on shaping gut microbiota composition, the genetic determinants of oral microbiota remain largely unexplored, especially in the context of oral diseases. Here, we performed a microbiome genome-wide association study in 2 independent cohorts of patients with oral squamous cell carcinoma (OSCC, n = 144 and 67) and an additional group of noncancer individuals (n = 104). Besides oral bacterial dysbiosis and signatures observed in OSCC, associations of 3 loci with the abundance of genus-level taxa and 4 loci with β diversity measures were detected (q < 0.05) at the discovery stage. The most significant hit (rs10906082 with the genus Lachnoanaerobaculum, P = 3.55 × 10^-9 at discovery stage) was replicated in a second OSCC cohort. Moreover, the other 2 taxonomical associations, rs10973953 with the genus Kingella (P = 1.38 × 10^-9) and rs4721629 with the genus Parvimonas (P = 3.53 × 10^-8), were suggestive in the meta-analysis combining 2 OSCC cohorts. Further pathway analysis revealed that these loci were enriched for genes in regulation of oncogenic and angiogenic responses, implicating a genetic anchor to the oral microbiome in estimation of casual relationships with OSCC. Our findings delineate the role of host genotypes in influencing the structure of oral microbial communities.

HCV eradication with DAAs differently affects HIV males and females: A whole miRNA sequencing characterization

Gender-specific consequences after HCV eradication are unexplored. MicroRNAs (miRNAs) play a crucial role in the immune response against viral infections. However, few have highlighted miRNA role in sex-biased disease or therapy response. We aim to assess gender differences reflected in the miRNA expression of HIV/HCV-coinfected patients who achieve sustained virological response (SVR) with direct acting antivirals (DAAs). We conducted a prospective study of miRNA expression in PBMCs from 28 chronic HIV/HCV-coinfected patients (HIV/HCV) at baseline and after achieving SVR with DAAs. Sixteen HIV-monoinfected patients (HIV) and 36 healthy controls (HC) were used as controls. Identification of significant differentially expressed (SDE) miRNAs was performed with generalized linear model and mixed GLMs. We also explored putative dysregulated biological pathways. At baseline, the HIV/HCV patients showed differences in the miRNA profile concerning the HIV group (165 and 102 SDE miRNAs for males and females, respectively). Gender-stratified analysis of HIV/HCV group at baseline versus at SVR achievement showed higher differences in males (80 SDE miRNAs) than in females (55 SDE miRNAs). After SVR, HIV/HCV group showed similar values to HIV individuals, especially in females (1 SDE miRNA). However, ten miRNAs in males remained dysregulated, which were mainly involved in cancer, fatty acid, and inflammatory pathways. Taken together, our results show gender-biased dysregulation in the miRNA expression profile of PBMCs after HCV eradication with DAAs. These differences were normalized in females, while miRNA profile and their target-related pathways in males lack of normalization, which may be related to a high-risk of developing liver-related complications.

Virus-Induced Tumorigenesis and IFN System

Oncogenic viruses favor the development of tumors in mammals by persistent infection and specific cellular pathways modifications by deregulating cell proliferation and inhibiting apoptosis. They counteract the cellular antiviral defense through viral proteins as well as specific cellular effectors involved in virus-induced tumorigenesis. Type I interferons (IFNs) are a family of cytokines critical not only for viral interference but also for their broad range of properties that go beyond the antiviral action. In fact, they can inhibit cell proliferation and modulate differentiation, apoptosis, and migration. However, their principal role is to regulate the development and activity of most effector cells of the innate and adaptive immune responses. Various are the mechanisms by which IFNs exert their effects on immune cells. They can act directly, through IFN receptor triggering, or indirectly by the induction of chemokines, the secretion of further cytokines, or by the stimulation of cells useful for the activation of particular immune cells. All the properties of IFNs are crucial in the host defense against viruses and bacteria, as well as in the immune surveillance against tumors. IFNs may be affected by and, in turn, affect signaling pathways to mediate anti-proliferative and antiviral responses in virus-induced tumorigenic context. New data on cellular and viral microRNAs (miRNAs) machinery, as well as cellular communication and microenvironment modification via classical secretion mechanisms and extracellular vesicles-mediated delivery are reported. Recent research is reviewed on the tumorigenesis induced by specific viruses with RNA or DNA genome, belonging to different families (i.e., HPV, HTLV-1, MCPyV, JCPyV, Herpesviruses, HBV, HCV) and the IFN system involvement.

IKKε isoform switching governs the immune response against EV71 infection

The reciprocal interactions between pathogens and hosts are complicated and profound. A comprehensive understanding of these interactions is essential for developing effective therapies against infectious diseases. Interferon responses induced upon virus infection are critical for establishing host antiviral innate immunity. Here, we provide a molecular mechanism wherein isoform switching of the host IKKε gene, an interferon-associated molecule, leads to alterations in IFN production during EV71 infection. We found that IKKε isoform 2 (IKKε v2) is upregulated while IKKε v1 is downregulated in EV71 infection. IKKε v2 interacts with IRF7 and promotes IRF7 activation through phosphorylation and translocation of IRF7 in the presence of ubiquitin, by which the expression of IFNβ and ISGs is elicited and virus propagation is attenuated. We also identified that IKKε v2 is activated via K63-linked ubiquitination. Our results suggest that host cells induce IKKε isoform switching and result in IFN production against EV71 infection. This finding highlights a gene regulatory mechanism in pathogen-host interactions and provides a potential strategy for establishing host first-line defense against pathogens.

The Upregulation of a Novel Long Noncoding RNA AK097647 Promotes Enterovirus 71 Replication and Decreases IFN-λ1 Secretion

BACKGROUND

Enterovirus 71 (EV71) infects millions of children every year in China and has become a challenge to public health. However, there is no effective treatment for EV71 infection. Long noncoding RNAs (lncRNAs) have been found to play various roles in virus replication and infection.

OBJECTIVE

We aimed to explore the role of a novel long noncoding RNA AK097647 (lncRNA-AK097647) during EV71 infection.

METHODS

To assess the role of lncRNA-AK097647 during EV71 infection, siRNAs were used to silence lncRNA-K097647 expression. RT-qPCR assay and Western blotting were applied to measure the mRNA and protein levels of EV71 VP1 and the phosphorylation of NF-κB. ELISA was used to detect the level of IFN-λ1 expression.

RESULTS

The novel lncRNA-AK097647 was upregulated in human rhabdomyosarcoma cells and the blood of hand, foot, and mouth disease patients infected with EV71, as demonstrated by RT-qPCR. Interestingly, RNAi-mediated knockdown of lncRNA-AK097647 dramatically increased the level of IFN-λ1 expression, resulting in the suppression of EV71 replication. In contrast, overexpression of lncRNA-AK097647 decreased the level of IFN-λ1 expression and resulted in increased EV71 replication. In addition, we found that lncRNA-AK097647 could inhibit the phosphorylation of NF-κB.

CONCLUSION

These results suggest a novel mechanism by which EV71 evades the IFN-mediated host antiviral response by increasing lncRNA-AK097647 expression.

The Epigenetic Modulation of Cancer and Immune Pathways in Hepatitis B Virus-Associated Hepatocellular Carcinoma: The Influence of HBx and miRNA Dysregulation

Hepatitis B virus (HBV)-associated hepatocellular carcinoma (HBV-HCC) pathogenesis is fueled by persistent HBV infection that stealthily maintains a delicate balance between viral replication and evasion of the host immune system. HBV is remarkably adept at using a combination of both its own, as well as host machinery to ensure its own replication and survival. A key tool in its arsenal, is the HBx protein which can manipulate the epigenetic landscape to decrease its own viral load and enhance persistence, as well as manage host genome epigenetic responses to the presence of viral infection. The HBx protein can initiate epigenetic modifications to dysregulate miRNA expression which, in turn, can regulate downstream epigenetic changes in HBV-HCC pathogenesis. We attempt to link the HBx and miRNA induced epigenetic modulations that influence both the HBV and host genome expression in HBV-HCC pathogenesis. In particular, the review investigates the interplay between CHB infection, the silencing role of miRNA, epigenetic change, immune system expression and HBV-HCC pathogenesis. The review demonstrates exactly how HBx-dysregulated miRNA in HBV-HCC pathogenesis influence and are influenced by epigenetic changes to modulate both viral and host genome expression. In particular, the review identifies a specific subset of HBx induced epigenetic miRNA pathways in HBV-HCC pathogenesis demonstrating the complex interplay between HBV infection, epigenetic change, disease and immune response. The wide-ranging influence of epigenetic change and miRNA modulation offers considerable potential as a therapeutic option in HBV-HCC.

The microRNA analysis portal is a next-generation tool for exploring and analyzing miRNA-focused data in the literature

MicroRNAs constitute a class of noncoding small RNAs involved in the posttranscriptional regulation of many biological pathways. In recent years, microRNAs have also been associated with regulation across kingdoms, demonstrating that exogenous miRNAs can function in mammals in a fashion similar to mammalian miRNAs. The growing interest in microRNAs and the increasing amount of literature and molecular and biomedical data available make it difficult to identify records of interest and keep up to date with novel findings. For these reasons, we developed the microRNA Analysis Portal (MAP). MAP selects relevant miRNA-focused articles from PubMed, links biomedical and molecular data and applies bioinformatics modules. At the time of this writing, MAP represents the richest, most complete and integrated database focused on microRNAs. MAP also integrates an updated version of MirCompare (2.0), a computational platform used for selecting plant microRNAs on the basis of their ability to regulate mammalian genes. Both MAP and MirCompare functionalities were used to predict that microRNAs from Moringa oleifera have putative roles across kingdoms by regulating human genes coding for proteins of the immune system. Starting from a selection of 94 human microRNAs, MirCompare selected 6 Moringa oleifera functional homologs. The subsequent prediction of human targets and areas of functional enrichment highlighted the central involvement of these genes in regulating immune system processes, particularly the host-virus interaction processes in hepatitis B, cytomegalovirus, papillomavirus and coronavirus. This case of use showed how MAP can help to perform complex queries without any computational background. MAP is available at http://stablab.uniroma2.it/MAP .

Identification of a MicroRNA Signature Associated With Lymph Node Metastasis in Endometrial Endometrioid Cancer

Background

Lymph node metastasis (LNM) is an important prognostic factor in endometrial cancer. Anomalous microRNAs (miRNAs) are associated with cell functions and are becoming a powerful tool to characterize malignant transformation and metastasis. The aim of this study was to construct a miRNA signature to predict LNM in endometrial endometrioid carcinoma (EEC).

Method

Candidate target miRNAs related to LNM in EEC were screened by three methods including differentially expressed miRNAs (DEmiRs), weighted gene co-expression network analysis (WGCNA), and decision tree algorithms. Samples were randomly divided into the training and validation cohorts. A miRNA signature was built using a logistic regression model and was evaluated by the area under the curve (AUC) of receiver operating characteristic curve (ROC) and decision curve analysis (DCA). We also conducted pathway enrichment analysis and miRNA-gene regulatory network to look for potential genes and pathways engaged in LNM progression. Survival analysis was performed, and the miRNAs were tested whether they expressed differently in another independent GEO database.

Result

Thirty-one candidate miRNAs were screened and a final 15-miRNA signature was constructed by logistic regression. The model showed good calibration in the training and validation cohorts, with AUC of 0.824 (95% CI, 0.739-0.912) and 0.821 (95% CI, 0.691-0.925), respectively. The DCA demonstrated the miRNA signature was clinically useful. Hub miRNAs in signature seemed to contribute to EEC progression via mitotic cell cycle, cellular protein modification process, and molecular function. MiR-34c was statistically significant in survival that a higher expression of miR-34c indicated a higher survival time. MiR-34c-3p, miR-34c-5p, and miR-34b-5p were expressed differentially in GSE75968.

Conclusion

The miRNA signature could work as a noninvasive method to detect LNM in EEC with a high prediction accuracy. In addition, miR-34c cluster may be a key biomarker referring LNM in endometrial cancer.

Essential Role of Non-Coding RNAs in Enterovirus Infection: From Basic Mechanisms to Clinical Prospects

Enteroviruses (EVs) are common RNA viruses that can cause various types of human diseases and conditions such as hand, foot, and mouth disease (HFMD), myocarditis, meningitis, sepsis, and respiratory disorders. Although EV infections in most patients are generally mild and self-limiting, a small number of young children can develop serious complications such as encephalitis, acute flaccid paralysis, myocarditis, and cardiorespiratory failure, resulting in fatalities. Established evidence has suggested that certain non-coding RNAs (ncRNAs) such as microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs) are involved in the occurrence and progression of many human diseases. Recently, the involvement of ncRNAs in the course of EV infection has been reported. Herein, the authors focus on recent advances in the understanding of ncRNAs in EV infection from basic viral pathogenesis to clinical prospects, providing a reference basis and new ideas for disease prevention and research directions.

Current and Future Perspectives of PD-1/PDL-1 Blockade in Cancer Immunotherapy

Cancer immunotherapy, which reactivates weakened immune cells of cancer patients, has yielded great success in recent years. Among immunotherapeutic agents, immune checkpoint inhibitors have been of particular interest and have gained approval by the FDA for treatment of cancers. Immune checkpoint blockade through targeting programmed cell death protein-1 (PD-1) has demonstrated promising antitumor effects in cancer immunotherapy of many different solid and hematologic malignancies. However, despite promising results, a favorable response is observed only in a fraction of patients, and there is still lack of a single therapy modality with curative ability. In this paper, we review the current and future perspectives of PD-1/L1 blockade in cancer immunotherapy, with a particular focus on predictive biomarkers of response to therapy. We also discuss the adverse events associated with PD-1/L1/2 inhibitors, ranging from severe life-threatening conditions such as autoimmune myocarditis to mild and moderate reactions such as skin rashes, and explore the potential strategies for improving the efficacy of immunotherapy with PD-1/L1 checkpoint inhibitors.

Five Circular RNAs in Metabolism Pathways Related to Prostate Cancer

Prostate cancer (PCa) is the most common malignant tumor in men, and its incidence increases with age. Serum prostate-specific antigen and tissue biopsy remain the standard for diagnosis of suspected PCa. However, these clinical indicators may lead to aggressive overtreatment in patients who have been treated sufficiently with active surveillance. Circular RNAs (circRNAs) have been recently recognized as a new type of regulatory RNA that is not easily degraded by RNases and other exonucleases because of their covalent closed cyclic structure. Thus, we utilized high-throughput sequencing data and bioinformatics analysis to identify specifically expressed circRNAs in PCa and filtered out five specific circRNAs for further analysis—hsa_circ_0006410, hsa_circ_0003970, hsa_circ_0006754, hsa_circ_0005848, and a novel circRNA, hsa_circ_AKAP7. We constructed a circRNA-miRNA regulatory network and used miRNA and differentially expressed mRNA interactions to predict the function of the selected circRNAs. Furthermore, survival analysis of their cognate genes and PCR verification of these five circRNAs revealed that they are closely related to well-known PCa pathways such as the MAPK signaling pathway, P53 pathway, androgen receptor signaling pathway, cell cycle, hormone-mediated signaling pathway, and cellular lipid metabolic process. By understanding the related metabolism of circRNAs, these circRNAs could act as metabolic biomarkers, and monitoring their levels could help diagnose PCa. Meanwhile, the exact regulatory mechanism for AR-related regulation in PCa is still unclear. The circRNAs we found can provide new solutions for research in this field.

miRNA-Based Therapeutics in the Era of Immune-Checkpoint Inhibitors

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression by binding to complementary target regions on gene transcripts. Thus, miRNAs fine-tune gene expression profiles in a cell-type-specific manner and thereby regulate important cellular functions, such as cell growth, proliferation and cell death. MiRNAs are frequently dysregulated in cancer cells by several mechanisms, which significantly affect the course of the disease. In this review, we summarize the current knowledge on how dysregulated miRNAs contribute to cancer and how miRNAs can be exploited as predictive factors and therapeutic targets, particularly in regard to immune-checkpoint inhibitor therapies.

The Multiple Roles of Hepatitis B Virus X Protein (HBx) Dysregulated MicroRNA in Hepatitis B Virus-Associated Hepatocellular Carcinoma (HBV-HCC) and Immune Pathways

Currently, the treatment of hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC) [HBV-HCC] relies on blunt tools that are unable to offer effective therapy for later stage pathogenesis. The potential of miRNA to treat HBV-HCC offer a more targeted approach to managing this lethal carcinoma; however, the complexity of miRNA as an ancillary regulator of the immune system remains poorly understood. This review examines the overlapping roles of HBx-dysregulated miRNA in HBV-HCC and immune pathways and seeks to demonstrate that specific miRNA response in immune cells is not independent of their expression in hepatocytes. This interplay between the two pathways may provide us with the possibility of using candidate miRNA to manipulate this interaction as a potential therapeutic option.

MicroRNA 876-5p modulates EV-A71 replication through downregulation of host antiviral factors

BACKGROUND

Human enterovirus 71 (EV-A71) is a non-enveloped virus that has a single stranded positive sense RNA genome. In a previous study, we showed that miR-876-5p upregulation was observed in the serum of patients with severe EV-A71 infection. Micro-876-5p (miR-876-5p) is a circulating miRNA that can be identified to modulate EV-A71 infections through both in vitro and in vivo studies. However, the regulatory mechanisms that involve miR-876-5p in the EV-A71 infection cycle remain unclear.

METHODS

We demonstrated that miR-876-5p facilitated EV-A71 replication and expression by overexpression and knocking-down of miR-876-5p through the transfection of miR-876-5p plasmid and miR-876-5p inhibitor. Although miR-876-5p suppressed CREB5 expression, luciferase reporter assay confirmed this. We also evaluated the role of miR-876-5p in the EV-A71 infection cycle by CREB5 mediated by transfection with an anti-miR-876-5P inhibitor or in combination with an si-CREB5 plasmid.

RESULTS

MicroR-876-5p was upregulated in EV-A71-infected neuroblastoma cells. Overexpression of miR-876-5p or knockdown of cyclic-AMP responsive element binding protein 5 (CREB5) promoted EV-A71 replication. The downregulation of miR-876-5p inhibited the accumulation of viral RNA and the production of viral proteins. Interestingly, CREB5 overexpression also suppressed EV-A71 replication. Our in vitro studies reveal that miR-876-5p directly targets CREB5. Finally, downregulation of CREB5 protein abated the inhibitory effect of anti-miR-876-5p and induced inhibitory effect of EV-A71 replication.

CONCLUSIONS

Our results suggest that intracellular miR-876-5p promotes EV-A71 replication indirectly by targeting the host CREB5 protein.

MicroRNA-218 inhibits type I interferon production and facilitates virus immune evasion via targeting RIG-I

The host protective immunity against viral infection requires the effective detection of viral antigens and the subsequent production of type I interferons (IFNs) by host immune cells. Retinoic acid-inducible gene I (RIG-I) is the crucial signaling element responsible for sensing viral RNA component and initiating the downstream antiviral signaling pathways, leading to the production of type I IFNs. In this work, we identified microRNA-218 (miR-218) as a new virus-induced miRNA that dampens the expression of RIG-I in mouse and human macrophages, leading to the impaired production of type I IFNs. Interfering miR-218 expression rescued RIG-I-mediated antiviral signaling and thus protected macrophages from viral infection. Hence, our results provide new understanding of miRNA-mediated viral immune evasion and may be potentially useful for the treatment of viral infection in the future.

The Regulatory Role of MicroRNA in Hepatitis-B Virus-Associated Hepatocellular Carcinoma (HBV-HCC) Pathogenesis

The incidence and mortality of hepatitis B virus (HBV)-associated hepatocellular carcinoma (HBV-HCC) is an intractable public health problem in developing countries that is compounded by limited early detection and therapeutic options. Despite the early promise of utilizing the regulatory role of miRNA in liver cancer, this field remains largely in the work-in-progress phase. This exploratory review paper adopts a broad focus in order to collate evidence of the regulatory role of miRNA in each stage of the HBV-HCC continuum. This includes the regulatory role of miRNA in early HBV infection, chronic inflammation, fibrosis/cirrhosis, and the onset of HCC. The paper specifically investigates HBV dysregulated miRNA that influence the expression of the host/HBV genome in HBV-HCC pathogenesis and fully acknowledges that this does not cover the full spectrum of dysregulated miRNA. The sheer number of dysregulated miRNA in each phase support a hypothesis that future therapeutic interventions will need to consider incorporating multiple miRNA panels.

miR-545 promoted enterovirus 71 replication via directly targeting phosphatase and tensin homolog and tumor necrosis factor receptor-associated factor 6

Enterovirus 71 (EV71) is a small, nonenveloped icosahedral RNA virus and is the predominant causative pathogen of hand-foot-and-mouth disease. Recently, microRNAs (miRNAs) are reported to play important roles in the pathogenesis of EV71 replication. This study investigated the role of miR-545 in the EV71 replication and explored the underlying molecular mechanisms. We showed that miR-545 was upregulated in the EV71-infected human embryonic kidney (HEK) 293 cells and rhabdomyosarcoma (RD) cells. Overexpression of miR-545 promoted the viral replication of EV71 and attenuated the inhibitory effects of EV71 on cell viability in HEK293 and RD cells; while knockdown of miR-545 significantly suppressed the EV71 replication in these two cell lines. Bioinformatics analysis and luciferase reporter assay showed that miR-545 directly targeted the 3'untranslated region of phosphatase and tensin homolog (PTEN) and tumor necrosis factor receptor-associated factor 6 (TRAF6) in HEK293 cells. Furthermore, miR-545 negatively regulated the messenger RNA (mRNA) and protein expression of PTEN and TRAF6. The mRNA and protein expression of PTEN and TRAF6 was also suppressed by EV71 infection, which was attenuated by miR-545 knockdown in HEK293 cells. Overexpression of PTEN and TRAF6 both suppressed the EV71 replication in HKE293 cells, and also attenuated the enhanced effects of miR-545 overexpression on the EV71 replication in HEK293 cells. Collectively, our study for the first time showed that miR-545 had an enhanced effect on the EV71 replication in HEK293 and RD cells. Further mechanistic results indicated that miR-545 promoted EV71 replication at least partly via targeting PTEN and TRAF6.

Potential role of lncRNA-TSIX, miR-548-a-3p, and SOGA1 mRNA in the diagnosis of hepatocellular carcinoma

Recent trends are moving towards the use of the circulating transcriptome as a potential diagnostic and therapeutic tool for hepatocellular carcinoma (HCC). The aim of this study is to identify circulatory RNA based biomarker panel, in addition to their relationship to the outcome in HCC. First, utilizing bioinformatics tools, we selected an HCC-specific RNA-based biomarker panel that depended on the integration of suppressor of glucose autophagy-associated (SOGA1) gene expression with the chosen panel of epigenetic regulators of this gene [long non-coding RNA antisense for X-inactive-specific transcript (lncRNA-TSIX) and microRNA-548-a-3p (miR-548-a-3p)]. Second, we attempted to validate these biomarkers using the sera of 65 patients with HCC, 34 patients with chronic hepatitis C virus (CHC) infection and 32 healthy volunteers. Finally, the expression levels of the chosen RNA-based biomarker panel were assessed in the serum samples using qRT-PCR assays. The panel of 3 RNA-based biomarkers (lncRNA-TSIX, miR-548-a-3p, and SOGA1) exhibited high sensitivity and specificity in differentiating HCC patients from CHC patients and healthy controls. Among these 3 RNAs, serum lncRNA-TSIX and SOGA1 were independent prognostic factor. The chosen circulatory RNA-based biomarker panel may serve as a diagnostic and prognostic biomarker for HCC.

Epigallocatechin gallate (EGCG) and miR-548m reduce HCV entry through repression of CD81 receptor in HCV cell models

Epigallocatechin gallate (EGCG) is the most abundant component in green tea extract, that has powerful antioxidant and antiviral effects. It has been previously reported to inhibit HCV entry via several mechanisms. Hence, this study aimed at further investigating the potential impact of EGCG on HCV entry through regulation of the expression of tetraspanin receptor CD81 by the novel predicted miR-548m. Liver biopsies were obtained from 29 HCV patients and 10 healthy controls for expression profiling. Huh7 cells were stimulated with EGCG and subsequently miR-548m expression was assessed. Naïve, HCV- ED43/JFH-1 and HCV-JFH-1 infected Huh7 cells were transfected by miR-548m mimics and inhibitors. Consequently, CD81 protein and mRNA levels were assessed using flow cytometry and qRT-PCR, respectively. Additionally, these cells were used to investigate HCV permissiveness into Huh7 cells using qRT-PCR for viral quantification. Direct binding confirmation of miR-548m to CD81 was done using luciferase reporter assay. In-silico analysis revealed miR-548m to have two potential binding sites in the 3'UTR of CD81 mRNA. EGCG boosted miR-548m expression in Huh7 cells. Additionally, miR-548m caused a downregulation of CD81 protein and mRNA levels as well as reduction in HCV infectivity of Huh7 cells. Luciferase binding assay confirmed the binding of miR-548m to CD81 mRNA at the two predicted binding sites. Intriguingly, miR-548m expression was not detected in healthy liver biopsies but was found in liver biopsies of HCV patients. This study shows that EGCG might act as an anti-HCV agent that reduces cellular infectivity via enhancing miR-548m expression and repressing CD81 receptor.

hsa_circRNA_104597: a novel potential diagnostic and therapeutic biomarker for schizophrenia

Aim: To assess whether expression of circular RNAs (circRNAs) in peripheral blood mononuclear cells can serve as a biomarker for diagnosis and/or therapeutic response in people living with schizophrenia (SZ). Materials & methods: Differentially expressed circRNAs were screened via microarray in nine individuals living with SZ and nine healthy controls, then quantified using real-time quantitative reverse transcription PCR in SZ (n = 102) and healthy control (n = 103) groups. CircRNAs were re-assessed twice in 30 randomly selected individuals living with SZ after 4- and 8-week antipsychotic treatments. Results: Five circRNAs were differentially expressed between groups. Only hsa_circRNA_104597, which was downregulated in the SZ group, was significantly upregulated after 8-week treatment. Conclusion: Dysregulation of hsa_circRNA_104597 may serve as a novel potential diagnostic and therapeutic biomarker for SZ.

Downregulation of exosome-encapsulated miR-548c-5p is associated with poor prognosis in colorectal cancer

The role of circulating exosomal microRNAs (miRNAs) in colorectal cancer (CRC) has drawn more and more attention during the past few years. Previously, we have identified several specific miRNAs in serum exosomes as potential CRC biomarkers. However, little is known about the association between exosome-encapsulated miR-548c-5p and outcomes of patients with CRC. In the current study, the expression of serum exosomal miR-548c-5p was investigated by quantitative real-time polymerase chain reaction. Its correlation with CRC prognosis was estimated by Kaplan-Meier survival and log-rank tests. Cox regression analysis based on uni- and multivariate analyses was performed to estimate the relationship of exosome-encapsulated miR-548c-5p with the clinicopathological factors of patients with CRC. Reduced levels of serum exosomal miR-548c-5p were more significant in CRC patients with liver metastasis and at later TNM stage (III/IV tumor stages). Serum exosomal miR-548c-5p could inhibit the proliferation of CRC cells, while the precise molecular mechanisms warranted further elucidation. In addition, decreased levels of serum exosomal miR-548c-5p were independently associated with shorter overall survival in CRC adjusted by age, sex, tumor grade vascular infiltration, TNM stage (III/IV tumor stages) and metastasis (hazard ratio = 3.40, 95% confidence interval 1.02-11.27; P = 0.046). The downregulation of exosomal miR-548c-5p in serum predicts poor prognosis in patients with CRC. Exosomal miR-548c-5p may be a critical biomarker for CRC diagnosis and prognosis.

A genetic variant associated with multiple sclerosis inversely affects the expression of CD58 and microRNA-548ac from the same gene

Genome-wide association studies have identified more than 200 genetic variants to be associated with an increased risk of developing multiple sclerosis (MS). Still, little is known about the causal molecular mechanisms that underlie the genetic contribution to disease susceptibility. In this study, we investigated the role of the single-nucleotide polymorphism (SNP) rs1414273, which is located within the microRNA-548ac stem-loop sequence in the first intron of the CD58 gene. We conducted an expression quantitative trait locus (eQTL) analysis based on public RNA-sequencing and microarray data of blood-derived cells of more than 1000 subjects. Additionally, CD58 transcripts and mature hsa-miR-548ac molecules were measured using real-time PCR in peripheral blood samples of 32 MS patients. Cell culture experiments were performed to evaluate the efficiency of Drosha-mediated stem-loop processing dependent on genotype and to determine the target genes of this underexplored microRNA. Across different global populations and data sets, carriers of the MS risk allele showed reduced CD58 mRNA levels but increased hsa-miR-548ac levels. We provide evidence that the SNP rs1414273 might alter Drosha cleavage activity, thereby provoking partial uncoupling of CD58 gene expression and microRNA-548ac production from the shared primary transcript in immune cells. Moreover, the microRNA was found to regulate genes, which participate in inflammatory processes and in controlling the balance of protein folding and degradation. We thus uncovered new regulatory implications of the MS-associated haplotype of the CD58 gene locus, and we remind that paradoxical findings can be encountered in the analysis of eQTLs upon data aggregation. Our study illustrates that a better understanding of RNA processing events might help to establish the functional nature of genetic variants, which predispose to inflammatory and neurological diseases.

miRNA-548ah promotes the replication and expression of hepatitis B virus by targeting histone deacetylase 4

AIM

Many studies have shown that some microRNAs (miRNAs) play an important role in the pathogenesis of chronic hepatitis B (CHB) infection. In this study, we aimed to explore the role and molecular mechanism of miRNA-548ah in the replication and expression of the hepatitis B virus (HBV).

MAIN METHODS

Overexpression and knockdown of miRNA-548ah were performed in three hepatoma cell lines with HBV replication and in a murine HBV model injected with adenovirus HBV vector. The effect of miRNA-548ah on its target gene, histone deacetylase (HDAC) 4, were confirmed in in vitro studies and further investigated in liver tissues from CHB patients.

KEY FINDINGS

miRNA-548ah significantly increased the expression of HBV in hepatoma cell lines and in a HBV mouse model. The expression level of covalently closed circular DNA (cccDNA) in the miRNA-548ah mimics group was significantly higher than the negative control group and significantly lower in the miRNA-548ah inhibitor group. The HBV core antigen promotes the expression of miRNA-548ah in hepatocytes. Finally, we observed a negative correlation between the expression of miRNA-548ah and HDAC4 in the liver tissue of patients with CHB.

SIGNIFICANCE

miRNA-548ah promoted the replication and expression of HBV through the regulation of the target gene, HDAC4. Inhibition of HDAC4 by miRNA-548ah might influence the deacetylation state of histones binding to cccDNA, thereby enhancing the replication of cccDNA. The HBV core antigen might increase the expression of miRNA-548ah. These results may provide new potential molecular targets for the prevention and treatment of CHB.

IL28B, IL29 and micro-RNA 548 in subacute sclerosing panencephalitis as a rare disease

Subacute sclerosing panencephalitis (SSPE) is a progressive neurodegenerative disease which affects children and young adults, caused by a persistent infection of defective measles virus. IFN-λs (IL-28A, IL-28B and IL-29) are a group of cytokines mediating antiviral responses. It has been shown that IL-29 levels are significantly higher in infected cells with defective measles virus. IL-29 expression is thought to be regulated at post-transcriptional level and miRNA-548 family targets the 3'UTR of the IFNL1 gene. Impaired immune system has an important role as well as viral factors in SSPE. The aim of our study investigates whether IL-28B, IL-29 levels and gene polymorphisms contribute to the damaged immune response leading to the development of SSPE. Also possible association of miR-548 family with IL-29 and SSPE is explored. Frequencies of rs12979860, rs8099917, rs30461, serum levels of IL-28B, IL-29 and expression levels of miR-548b, miR-548c, miR-548i are determined at 64 SSPE patients and 68 healthy controls. Serum IL-29 levels are statistically significant higher in SSPE patients. Allele frequencies of rs8099917 are statistically significant higher in SSPE patients and resulted G allele is found to increase 2.183-fold risk of SSPE. The expression levels of miR-548b-5p, miR-548c-5p and miR-548i are found to be statistically significant higher in SSPE patients. Dramatically increased level of IL-29 seen in patient group indicates that the elevated miR-548 expression is compensatory result of the over-activated immune system response. Further studies referred to IL28, IL29 and related miRNA's will be enlightened the pathogenesis of SSPE.

Inducible microRNA-590-5p inhibits host antiviral response by targeting the soluble interleukin-6 (IL6) receptor

MicroRNA (miR)-590-5p has been identified as an important regulator of some signaling pathways such as cell proliferation and tumorigenesis. However, little is known about its role during viral infection. Here, we report that miR-590-5p was significantly induced by various viruses and effectively potentiated virus replication in different viral infection systems. Furthermore, miR-590-5p substantially attenuated the virus-induced expression of type I and type III interferons (IFNs) and inflammatory cytokines, resulting in impaired downstream antiviral signaling. Interleukin-6 receptor (IL6R) was identified as a target of miR-590-5p. Interestingly, the role of miR-590-5p in virus-triggered signaling was abolished in IL6R knockout cells, and this could be rescued by restoring the expression of the soluble IL6R (sIL6R) but not the membrane-bound IL6R (mIL6R), suggesting that sIL6R is indispensable for miR-590-5p in modulating the host antiviral response. Furthermore, miR-590-5p down-regulated endogenous sIL6R and mIL6R expression through a translational repression mechanism. These findings thus uncover a previously uncharacterized role and the underlying mechanism of miR-590-5p in the innate immune response to viral infection.

Micro-RNAs in hepatitis B virus-related chronic liver diseases and hepatocellular carcinoma

MicroRNAs (miRNAs) are small non-coding RNAs that modulate gene expression at the post-transcriptional level by affecting both the stability and translation of complementary mRNAs. Several studies have shown that miRNAs are important regulators in the conflicting efforts between the virus (to manipulate the host for its successful propagation) and the host (to inhibit the virus), culminating in either the elimination of the virus or its persistence. An increasing number of studies report a role of miRNAs in hepatitis B virus (HBV) replication and pathogenesis. In fact, HBV is able to modulate different host miRNAs, particularly through the transcriptional transactivator HBx protein and, conversely, different cellular miRNAs can regulate HBV gene expression and replication by a direct binding to HBV transcripts or indirectly targeting host factors. The present review will discuss the role of miRNAs in the pathogenesis of HBV-related diseases and their role as a biomarker in the management of patients with HBV-related disease and as therapeutic targets.

Host MicroRNA hsa-miR-494-3p Promotes EV71 Replication by Directly Targeting PTEN

Many cellular processes are driven by spatially and temporally regulated microRNAs (miRNAs)-dependent signaling events. Substantial evidence collected over the years indicates that miRNAs are pivotal regulators that contribute to the initiation and development of EV71-related disorders. Importantly, so far, no clinical trial has been undertaken to address the effect of miRNAs on EV71-related diseases. In this study, we show that EV71 infection results in up-regulation of hsa-miR-494-3p levels, and that EV71-induced hsa-miR-494-3p impacts PI3K/Akt signaling pathway by targeting PTEN. However, very little is known about the relationship between hsa-miR-494-3p and EV71 infection. The overall goal of the study is to get a better insight into whether or not hsa-miR-494-3p is involved in the EV71 infection. We found that the EV71 infection induces cellular apoptosis, and that this process can be counteracted by the over-expression of hsa-miR-494-3p mimics. We also present evidence that cell lines deficient in hsa-miR-494-3p are more sensitive to EV71-induced cell death than the corresponding control cells. Collectively, these findings confirm and extend the pervious observation suggesting that disturbances in miRNAs expression can influence EV71 propagation. In addition, they lend strong support to the ideas that hsa-miR-494-3p-mediated signaling pathway plays an important role in the EV71 replication, and that this may have profound implications on our views on EV71-related diseases.

Circulating microRNAs associated with prolonged overall survival in lung cancer patients treated with nivolumab

BACKGROUND

The introduction of immune check-point inhibition in non-small cell lung cancer (NSCLC) therapy represents improved prospects for the patients. The response rates to check-point inhibitors are approximately 20% in unselected NSCLC patients. Increasing levels of tumor PD-L1 expression are associated with higher response rates. However, patients with low PD-L1 levels may also have durable responses, and improved strategies for patient stratification are needed.

MATERIAL AND METHODS

In this study, we investigated circulating microRNAs aiming to identify circulating predictive biomarkers associated with increased overall survival after immune check-point treatment. Using next generation sequencing, we performed microRNA profiling in serum from NSCLC patients (n = 20) treated with nivolumab. Serum samples from 31 patients were used for validation using qPCR assays. Serum samples were collected prior to immune therapy initiation.

RESULTS

Based on multivariate regression analysis, we identified a signature of seven microRNAs (miR-215-5p, miR-411-3p, miR-493-5p, miR-494-3p, miR-495-3p, miR-548j-5p and miR-93-3p) significantly associated with overall survival (OS) > 6 months in discovery cohort (p = .0003). We further validated this in another similar set of samples (n = 31) and the model was significantly associated with overall survival (OS) > 6 months (p = .001) with sensitivity and specificity of 71% and 90%, respectively.

CONCLUSIONS

In this study of circulating microRNAs, we have identified a 7-miR signature associated with survival in nivolumab-treated NSCLC patients. This signature may lead to better treatment options for patients with NSCLC, but a validation in an independent cohort is needed to confirm the predicted potential.

miRNAs in enterovirus infection

During the last years, it has become evident that miRNAs are important players in almost all physiological and pathological processes, including viral infections. Enterovirus infections range from mild to severe acute infections concerning several organ systems and are also associated with chronic diseases. In this review, we summarize the findings on the impact of acute and persistent enterovirus infection on the expression of cellular miRNAs. Furthermore, the currently available data on the regulation of cellular or viral targets by the dysregulated miRNAs are reviewed. Finally, a translational perspective, namely the use of miRNAs as biomarkers of enterovirus infection and as antiviral strategy is discussed.

MicroRNA miR-214 Inhibits Snakehead Vesiculovirus Replication by Promoting IFN-α Expression via Targeting Host Adenosine 5'-Monophosphate-Activated Protein Kinase

Background

Snakehead vesiculovirus (SHVV), a new rhabdovirus isolated from diseased hybrid snakehead, has emerged as an important pathogen during the past few years in China with great economical losses in snakehead fish cultures. However, little is known about the mechanism of its pathogenicity. MicroRNAs are small noncoding RNAs that posttranscriptionally modulate gene expression and have been indicated to regulate almost all cellular processes. Our previous study has revealed that miR-214 was downregulated upon SHVV infection.

Results

The overexpression of miR-214 in striped snakehead (SSN-1) cells inhibited SHVV replication and promoted IFN-α expression, while miR-214 inhibitor facilitated SHVV replication and reduced IFN-α expression. These findings suggested that miR-214 negatively regulated SHVV replication probably through positively regulating IFN-α expression. Further investigation revealed that adenosine 5′-monophosphate-activated protein kinase (AMPK) was a target gene of miR-214. Knockdown of AMPK by siRNA inhibited SHVV replication and promoted IFN-α expression, suggesting that cellular AMPK positively regulated SHVV replication and negatively regulated IFN-α expression. Moreover, we found that siAMPK-mediated inhibition of SHVV replication could be partially restored by miR-214 inhibitor, indicating that miR-214 inhibited SHVV replication at least partially via targeting AMPK.

Conclusion

The findings of this study complemented our early study, and provide insights for the mechanism of SHVV pathogenicity. SHVV infection downregulated miR-214, and in turn, the downregulated miR-214 increased the expression of its target gene AMPK, which promoted SHVV replication via reducing IFN-α expression. It can therefore assume that cellular circumstance with low level of miR-214 is beneficial for SHVV replication and that SHVV evades host antiviral innate immunity through decreasing IFN-α expression via regulating cellular miR-214 expression.

Interplay between Janus Kinase/Signal Transducer and Activator of Transcription Signaling Activated by Type I Interferons and Viral Antagonism

Interferons (IFNs), which were discovered a half century ago, are a group of secreted proteins that play key roles in innate immunity against viral infection. The major signaling pathway activated by IFNs is the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway, which leads to the expression of IFN-stimulated genes (ISGs), including many antiviral effectors. Viruses have evolved various strategies with which to antagonize the JAK/STAT pathway to influence viral virulence and pathogenesis. In recent years, notable progress has been made to better understand the JAK/STAT pathway activated by IFNs and antagonized by viruses. In this review, recent progress in research of the JAK/STAT pathway activated by type I IFNs, non-canonical STAT activation, viral antagonism of the JAK/STAT pathway, removing of the JAK/STAT antagonist from viral genome for attenuation, and the potential pathogenesis roles of tyrosine phosphorylation-independent non-canonical STATs activation during virus infection are discussed in detail. We expect that this review will provide new insight into the understanding the complexity of the interplay between JAK/STAT signaling and viral antagonism.

MicroRNA expression analysis of feline and canine parvovirus infection in vivo (felis)

Feline panleukopenia is a common contagious disease with high morbidity and mortality. At present, feline parvovirus (FPV) and canine parvovirus (CPV) variants are the pathogens of feline panleukopenia. Many studies have shown that miRNAs are involved in virus-host interactions. Nevertheless, miRNA expression profiling of FPV (original virus) or CPV-2b (new virus) in cats has not been reported. To investigate these profiles, three 10-week-old cats were orally inoculated with 106 TCID50 of the viruses (FPV and CPV-2b), and the jejunums of one cat in each group were sectioned for miRNA sequencing at 5 days post-inoculation (dpi). This study is the first attempt to use miRNA analysis to understand the molecular basis of FPV and CPV infection in cats. The miRNA expression profiles of the jejunums of cats infected with FPV and CPV were obtained, and a subset of miRNAs was validated by real-time qPCR. The results show that a variety of metabolism-related pathways, cytokine- and pathogen-host interaction-related pathways, and pathology- and cellar structure-related pathways, as well as others, were affected. Specifically, the JAK-STAT signaling pathway, which is critical for cytokines and growth factors, was enriched. This description of the miRNAs involved in regulating FPV and CPV infection in vivo provides further insight into the mechanisms of viral infection and adaptation and might provide an alternative antiviral strategy for disease control and prevention.

Maternal plasma miRNAs as biomarkers during mid-pregnancy to predict later spontaneous preterm birth: a pilot study

More than 10% of babies are born too early resulting in over 15 million preterm births and more than one million new-born deaths globally. Although women with a previous spontaneous preterm birth (SPTB) are considered at high risk for recurrence, the majority occur in women without prior history. Prediction of SPTB risk allows for improved care and potential for targeting novel and existing therapeutics to prevent SPTB, which may result in improved outcomes for infant and mother. In this pilot study, a miRNA array was used to analyse plasma from healthy women in their first pregnancy at 20 weeks of gestation who then went on to deliver either at term or experience SPTB at 28-32 weeks. We identified specific miRNA expression profiles that differentiated between those mothers who delivered at term or delivered following SPTB. miR302b, miR1253 and a clustering of miR548 miRNAs were underexpressed in SPTB cases compared to term controls. Conversely, miR223 was elevated in mothers that later experienced a SPTB. The circulating miRNAs identified in the present study may therefore be attractive candidates as non-invasive biomarkers for the early prediction of SPTB. Further larger studies are now warranted to investigate the potential clinical utility of these markers.

Identification and Expression of Equine MER-Derived miRNAs

MicroRNAs (miRNAs) are single-stranded, small RNAs (21-23 nucleotides) that function in gene silencing and translational inhibition via the RNA interference mechanism. Most miRNAs originate from host genomic regions, such as intergenic regions, introns, exons, and transposable elements (TEs). Here, we focused on the palindromic structure of medium reiteration frequencies (MERs), which are similar to precursor miRNAs. Five MER consensus sequences (MER5A1, MER53, MER81, MER91C, and MER117) were matched with paralogous transcripts predicted to be precursor miRNAs in the horse genome (equCab2) and located in either intergenic regions or introns. The MER5A1, MER53, and MER91C sequences obtained from RepeatMasker were matched with the eca-miR-544b, eca-miR-1302, and eca-miR-652 precursor sequences derived from Ensembl transcript database, respectively. Each precursor form was anticipated to yield two mature forms, and we confirmed miRNA expression in six different tissues (cerebrum, cerebellum, lung, spleen, adrenal gland, and duodenum) of one thorough-bred horse. MER5A1-derived miRNAs generally showed significantly higher expression in the lung than in other tissues. MER91C-derived miRNA-5p also showed significantly higher expression in the duodenum than in other tissues (cerebellum, lung, spleen, and adrenal gland). The MER117-overlapped expressed sequence tag generated polycistronic miRNAs, which showed higher expression in the duodenum than other tissues. These data indicate that horse MER transposons encode miR-NAs that are expressed in several tissues and are thought to have biological functions.