Uncovering the Roles of miR-214 in Hepatitis E Virus Replication

Potential role of microRNAs in personalized medicine against hepatitis: a futuristic approach

MicroRNAs (miRNAs) have been the subject of extensive research for many years, primarily in the context of diseases such as cancer. However, our appreciation of their significance in viral infections, particularly in hepatitis, has increased due to the discovery of their association with both the host and the virus. Hepatitis is a major global health concern and can be caused by various viruses, including hepatitis A to E. This review highlights the key factors associated with miRNAs and their involvement in infections with various viruses that cause hepatitis. The review not only emphasizes the expression profiles of miRNAs in hepatitis but also puts a spotlight on their potential for diagnostics and therapeutic interventions. Ongoing extensive studies are propelling the therapeutic application of miRNAs, addressing both current limitations and potential strategies for the future of miRNAs in personalized medicine. Here, we discuss the potential of miRNAs to influence future medical research and an attempt to provide a thorough understanding of their diverse roles in hepatitis and beyond.

miR-26a exerts broad-spectrum antiviral effects via the enhancement of RIG-I-mediated type I interferon response by targeting USP15

IMPORTANCE

miR-26a serves as a potent positive regulator of type I interferon (IFN) responses. By inhibiting USP15 expression, miR-26a promotes RIG-I K63-ubiquitination to enhance type I IFN responses, resulting in an active antiviral state against viruses. Being an intricate regulatory network, the activation of type I IFN responses could in turn suppress miR-26a expression to avoid the disordered activation that might result in the so-called "type I interferonopathy." The knowledge gained would be essential for the development of novel antiviral strategies against viral infection.

A Review of miRNA Regulation in Japanese Encephalitis (JEV) Virus Infection

Japanese encephalitis (JE) is a mosquito-borne disease that causes neuronal damage and inflammation of microglia, and in severe cases, it can be fatal. JE infection can resist cellular immune responses and survive in host cells. Japanese encephalitis virus (JEV) infects macrophages and peripheral blood lymphocytes. In addition to regulating biological signaling pathways, microRNAs in cells also influence virus-host interactions. Under certain circumstances, viruses can change microRNA production. These changes affect the replication and spread of the virus. Host miRNAs can contain viral pathogenicity by downregulating the antiviral immune response pathways. Simultaneous profiling of miRNA and messenger RNA (mRNA) could help us detect pathogenic factors, and dual RNA detection is possible. This work highlights important miRNAs involved in human JE infection. In this study, we have shown the important miRNAs that play significant roles in JEV infection. We found that during JEV infection, miRNA-155, miRNA-29b, miRNA-15b, miRNA-146a, miRNA-125b-5p, miRNA-30la, miRNA-19b-3p, and miRNA-124, cause upregulation of human genes whereas miRNA-432, miRNA-370, miRNA- 33a-5p, and miRNA-466d-3p are responsible for downregulation of human genes respectively. Further, these miRNAs are also responsible for the inflammatory effects. Although several other miRNAs critical to the JEV life cycle are yet unknown, there is currently no evidence for the role of miRNAs in persistence.

The roles of different microRNAs in the regulation of cholesterol in viral hepatitis

Cholesterol plays a significant role in stabilizing lipid or membrane rafts, which are specific cellular membrane structures. Cholesterol is involved in numerous cellular processes, including regulating virus entry into the host cell. Multiple viruses have been shown to rely on cholesterol for virus entry and/or morphogenesis. Research indicates that reprogramming of the host's lipid metabolism is associated with hepatitis B virus (HBV) and hepatitis C virus (HCV) infections in the progression to severe liver disease for viruses that cause chronic hepatitis. Moreover, knowing the precise mode of viral interaction with target cells sheds light on viral pathogenesis and aids in the development of vaccines and therapeutic targets. As a result, the area of cholesterol-lowering therapy is quickly evolving and has many novel antiviral targets and medications. It has been shown that microRNAs (miRNAs) either directly or indirectly target the viral genome, preventing viral replication. Moreover, miRNAs have recently been shown to be strong post-transcriptional regulators of the genes involved in lipid metabolism, particularly those involved in cholesterol homeostasis. As important regulators of lipid homeostasis in several viral infections, miRNAs have recently come to light. In addition, multiple studies demonstrated that during viral infection, miRNAs modulate several enzymes in the mevalonate/cholesterol pathway. As cholesterol metabolism is essential to the life cycle of viral hepatitis and other viruses, a sophisticated understanding of miRNA regulation may contribute to the development of a novel anti-HCV treatment. The mechanisms underlying the effectiveness of miRNAs as cholesterol regulators against viral hepatitis are explored in this review. Video Abstract.

miR-125b-5p, miR-155-3p, and miR-214-5p and Target E2F2 Gene in Oral Squamous Cell Carcinoma

It is known that E2F2 (E2F transcription factor 2) plays an important role as controller in the cell cycle. This study aimed to analyse the expression of the E2F2 gene and E2F2 protein and demonstrate E2F2 target microRNAs (miRNAs) candidates (miR-125b-5p, miR-155-3p, and miR-214-5p) in oral squamous cell carcinoma tumour and margin samples. The study group consisted 50 patients. The E2F2 gene and miRNAs expression levels were assessed by qPCR, while the E2F2 protein was assessed by ELISA. When analysing the effect of miRNAs expression on E2F2 gene expression and E2F2 protein level, we observed no statistically significant correlations. miR-125b-5p was downregulated, while miR-155-3p, and miR-214-5p were upregulated in tumour samples compared to margin. We observed a difference between the miR-125b-5p expression level in smokers and non-smokers in margin samples. Furthermore, HPV-positive individuals had a significantly higher miR-125b-5p and miR-214-5p expression level compared to HPV-negative patients in tumour samples. The study result showed that the E2F2 gene is not the target for analysed miRNAs in OSCC. Moreover, miR-155-3p and miR-125b-5p could play roles in the pathogenesis of OSCC. A differential expression of the analysed miRNAs was observed in response to tobacco smoke and HPV status.

Unravelling the tripartite interactions among Hepatitis E virus RNA, miR-140 and hnRNP K: Running title: Interactions between HEV-RNA, miR-140 and hnRNP K

In the present investigation, we have identified the functional significance of the highly conserved miR-140 binding site on the Hepatitis E Virus (HEV) genome. Multiple sequence alignment of the viral genome sequences along with RNA folding prediction indicated that the putative miR-140 binding site has significant conservation for sequence and secondary RNA structure among HEV genotypes. Site-directed mutagenesis and reporter assays indicated that an intact sequence of the miR-140 binding site is essential for HEV translation. Provision of mutant miR-140 oligos carrying same mutation as on mutant HEV successfully rescued mutant HEV replication. In vitro cell-based assays with modified oligos proved that host factor-miR-140 is a critical requirement for HEV replication. Biotinylated RNA pulldown and RNA immunoprecipitation assays proved that the predicted secondary RNA structure of the miR-140 binding site allows the recruitment of hnRNP K, which is a key protein of the HEV replication complex. We predicted the model from the obtained results that the miR-140 binding site can serve as a platform for recruitment of hnRNP K and other proteins of HEV replication complex only in the presence of miR-140.

Modulation of cellular autophagy by genotype 1 hepatitis E virus ORF3 protein

Hepatitis E virus (HEV) egresses from infected hepatocytes as quasienveloped particles containing open reading frame 3 (ORF3) protein. HEV ORF3 (small phosphoprotein) interacts with host proteins to establish a favourable environment for virus replication. It is a functional viroporin that plays an important role during virus release. Our study provides evidence that pORF3 plays a pivotal role in inducing Beclin1-mediated autophagy that helps HEV-1 replication as well as its exit from cells. The ORF3 interacts with host proteins involved in regulation of transcriptional activity, immune response, cellular and molecular processes, and modulation of autophagy, by interacting with proteins, DAPK1, ATG2B, ATG16L2 and also several histone deacetylases (HDACs). For autophagy induction, the ORF3 utilizes non-canonical NF-κB2 pathway and sequesters p52NF-κB and HDAC2 to upregulate DAPK1 expression, leading to enhanced Beclin1 phosphorylation. By sequestering several HDACs, HEV may prevent histone deacetylation to maintain overall cellular transcription intact to promote cell survival. Our findings highlight a novel crosstalk between cell survival pathways participating in ORF3-mediated autophagy.

miR-214-5p/C1QTNF1 axis enhances PCV2 replication through promoting autophagy by targeting AKT/mTOR signaling pathway

Porcine circovirus type 2 (PCV2) is the causative agent of PCV2-associated disease, which causes a relevant economic impact on the global swine industry. Accumulating data have indicated host microRNAs play essential roles in numerous virus replication of pigs, while their roles in PCV2 replication remain unclear. Herein, we demonstrated that PCV2 infection downregulated the expression of miR-214-5p in PK15 cells, and miR-214-5p promoted PCV2 replication. C1q/tumor necrosis factor-related protein 1 (C1QTNF1) was then identified as a target gene of miR-214-5p, and C1QTNF1 suppressed PCV2 replication. Interestingly, miR-214-5p/C1QTNF1 axis negatively regulated AKT/mTOR signaling, and then enhanced PCV2 replication through promoting autophagy in PK15 cells. Collectively, our findings provide insight into the mechanism of PCV2 replication and highlight miR-214-5p and C1QTNF1 as potential novel targets for the treatment of PCV2 infection.

Micro RNAs—The Small Big Players in Hepatitis E Virus Infection: A Comprehensive Review

The molecular mechanism of hepatitis E virus (HEV) pathology is still unclear. The micro RNAs (miRNAs), of host or viral origin, interfere with virus replication and host environment in order to create an appropriate condition for the production of mature HEV progeny. Understanding the biogenesis and the interference of miRNAs with HEV will help to revile the mechanism of viral pathogenesis.

Characterization of highly expressed novel hub genes in hepatitis E virus chronicity in rabbits: a bioinformatics and experimental analysis

BACKGROUND

Hepatitis E virus (HEV), which is the leading cause of acute viral hepatitis worldwide, usually causes self-limited infections in common individuals. However, it can lead to chronic infection in immunocompromised individuals and its mechanisms remain unclear. Rabbits are the natural host of HEV, and chronic HEV infections have been observed in rabbits. Therefore, we aimed to investigate potential key genes in HEV chronicity process in rabbits. In this study, both bioinformatics and experimental analysis were performed to deepen the understanding of hub genes in HEV chronic infection in rabbits.

RESULTS

Ninety-four candidate differentially expressed genes (DEGs) and the pathways they enriched were identified to be related with HEV chronicity. A total of 10 hub genes were found by protein-protein interaction (PPI) network construction. Rabbits of group P (n = 4) which showed symptoms of chronic HEV infection were selected to be compared with HEV negative rabbits (group N, n = 6). By detecting the identified hub genes in groups P and N by real-time PCR, we found that the expressions of MX1, OAS2 and IFI44 were significantly higher in group P (P < 0.05).

CONCLUSIONS

In this work, we presented that MX1, OAS2 and IFI44 were significantly upregulated in HEV chronic infected rabbits, indicating that they may be involved in the pathogenesis of HEV chronicity.

Regulatory Role of Host MicroRNAs in Flaviviruses Infection

MicroRNAs (miRNAs) are small non-coding RNA that affect mRNA abundance or translation efficiency by binding to the 3′UTR of the mRNA of the target gene, thereby participating in multiple biological processes, including viral infection. Flavivirus genus consists of small, positive-stranded, single-stranded RNA viruses transmitted by arthropods, especially mosquitoes and ticks. The genus contains several globally significant human/animal pathogens, such as Dengue virus, Japanese encephalitis virus, West Nile virus, Zika virus, Yellow fever virus, Tick-borne encephalitis virus, and Tembusu virus. After flavivirus invades, the expression of host miRNA changes, exerting the immune escape mechanism to create an environment conducive to its survival, and the altered miRNA in turn affects the life cycle of the virus. Accumulated evidence suggests that host miRNAs influence flavivirus replication and host–virus interactions through direct binding of viral genomes or through virus-mediated host transcriptome changes. Furthermore, miRNA can also interweave with other non-coding RNAs, such as long non-coding RNA and circular RNA, to form an interaction network to regulate viral replication. A variety of non-coding RNAs produced by the virus itself exert similar function by interacting with cellular RNA and viral RNA. Understanding the interaction sites between non-coding RNA, especially miRNA, and virus/host genes will help us to find targets for antiviral drugs and viral therapy.

MicroRNA-124 Promotes Singapore Grouper Iridovirus Replication and Negatively Regulates Innate Immune Response

Viral infections seriously affect the health of organisms including humans. Now, more and more researchers believe that microRNAs (miRNAs), one of the members of the non-coding RNA family, play significant roles in cell biological function, disease occurrence, and immunotherapy. However, the roles of miRNAs in virus infection (entry and replication) and cellular immune response remain poorly understood, especially in low vertebrate fish. In this study, based on the established virus-cell infection model, Singapore grouper iridovirus (SGIV)-infected cells were used to explore the roles of miR-124 of Epinephelus coioides, an economically mariculture fish in southern China and Southeast Asia, in viral infection and host immune responses. The expression level of E. coioides miR-124 was significantly upregulated after SGIV infection; miR-124 cannot significantly affect the entry of SGIV, but the upregulated miR-124 could significantly promote the SGIV-induced cytopathic effects (CPEs), the viral titer, and the expressions of viral genes. The target genes of miR-124 were JNK3/p38α mitogen-activated protein kinase (MAPK). Overexpression of miR-124 could dramatically inhibit the activation of NF-κB/activating protein-1 (AP-1), the transcription of proinflammatory factors, caspase-9/3, and the cell apoptosis. And opposite results happen when the expression of miR-124 was inhibited. The results suggest that E. coioides miR-124 could promote viral replication and negatively regulate host immune response by targeting JNK3/p38α MAPK, which furthers our understanding of virus and host immune interactions.

Interplay between Hepatitis E Virus and Host Cell Pattern Recognition Receptors

Hepatitis E virus (HEV) usually causes self-limiting acute hepatitis, but the disease can become chronic in immunocompromised individuals. HEV infection in pregnant women is reported to cause up to 30% mortality, especially in the third trimester. Additionally, extrahepatic manifestations like neuronal and renal diseases and pancreatitis are also reported during the course of HEV infection. The mechanism of HEV pathogenesis remains poorly understood. Innate immunity is the first line of defense triggered within minutes to hours after the first pathogenic insult. Growing evidence based on reverse genetics systems, in vitro cell culture models, and representative studies in animal models including non-human primates, has implicated the role of the host’s innate immune response during HEV infection. HEV persists in presence of interferons (IFNs) plausibly by evading cellular antiviral defense. This review summarizes our current understanding of recognizing HEV-associated molecular patterns by host cell Pattern Recognition Receptors (PRRs) in eliciting innate immune response during HEV infection as well as mechanisms of virus-mediated immune evasion.