miRNA Function Research Articles

Abstract 625: Alteration Of Circulating Ace2-network Related Micrornas In Patients With Covid-19

ACE2 interaction network caused by virus infection can affect the expression levels of miRNAs and influence severity of COVID19. This study aimed to analyse the diagnostic/predictive utility of ACE2-related miRNAs, identified by in silico analysis: miR10b, miR124, miR200b-3p, miR26b, miR302c-5p in patients with COVID-19, and aimed to unravel the functions of miRNAs, by using machine learning-SHAP analysis for clinical data and bioinformatic tools. Blood samples and clinical data of 79 patients and 32 healthy were collected at; day of admission, 7days and 21days after admission. Endpoint was hospitalisation length of stay (>21days) and/or death in follow-up. Delta low miR200b-3p expression (7days-admission) presents predictive utility in assessment of the hospital length of stay and/or death (AUC:0.73,p=0.002). Logistic regression analysis showed that delta low miR-200b-3p, diabetes are independent predictors of increased hospital length of stay and/or death (OR=5.8;CI=0.57-21.21;p= 0.008, OR= 4.9;CI=1-23.9;p=0.04). MiR-26b-5p and miR10b in patients were found lower at the baseline, 7 and 21days after admission compared to healthy controls (p<0.0001 for all time points). SHAP analysis showed miR200b-3p (day7), miR302c-5p (day7), CRP (day7), neutrophils (day0), and DDimer (day0) as most promising predictors of long hospitalisation. Pathway-enrichment showed the following top pathways of the interleukin-2 signaling pathway, and cancer pathways. MiR200b-3p showed regulation of COVID19-related targets associated with Tcell protein tyrosine phosphatase and HIF-1 transcriptional activity in hypoxia, key pathways in COVID19. Bioinformatics analysis showed miRNAs roles in multiple CVDs phenotypes associated with COVID19. We validated/characterized miRNAs which can serve as novel, predictive biomarkers of the long term COVID19 hospitalisation and can be used for early stratification of patients and prediction of severity of infection.

Interplay between LncRNAs and microRNAs in Breast Cancer.

(1) Although long noncoding RNAs (lncRNAs) are known to be precursors of microRNAs (miRNAs), they frequently act as competing endogoneous RNAs (ceRNAs), yet still their interplay with miRNA is not well known. However, their interaction with miRNAs may result in the modulation of miRNA action. (2) To determine the contribution of these RNA molecules in tumor resistance to chemotherapeutic drugs, it is essential to consider not only the oncogenic and tumor suppressive function of miRNAs but also the impact of lncRNAs on miRNAs. Therefore, we performed an extensive search in different databases including PubMed. (3) The present study concerns the interplay between lncRNAs and miRNAs in the regulatory post-transcriptional network and their impact on drugs used in the treatment of breast cancer. (4) Consideration of this interplay may improve the search for new drugs to circumvent chemoresistance.

MicroRNAs reshape the immunity of insects in response to bacterial infection.

The interaction between bacteria and insects can significantly impact a wide range of different areas because bacteria and insects are widely distributed around the globe. The bacterial-insect interactions have the potential to directly affect human health since insects are vectors for disease transmission, and their interactions can also have economic consequences. In addition, they have been linked to high mortality rates in economically important insects, resulting in substantial economic losses. MicroRNAs (miRNAs) are types of non-coding RNAs involved in regulating gene expression post-transcriptionally. The length of miRNAs ranges from 19 to 22 nucleotides. MiRNAs, in addition to their ability to exhibit dynamic expression patterns, have a diverse range of targets. This enables them to govern various physiological activities in insects, like innate immune responses. Increasing evidence suggests that miRNAs have a crucial biological role in bacterial infection by influencing immune responses and other mechanisms for resistance. This review focuses on some of the most recent and exciting discoveries made in recent years, including the correlation between the dysregulation of miRNA expression in the context of bacterial infection and the progression of the infection. Furthermore, it describes how they profoundly impact the immune responses of the host by targeting the Toll, IMD, and JNK signaling pathways. It also emphasizes the biological function of miRNAs in regulating immune responses in insects. Finally, it also discusses current knowledge gaps about the function of miRNAs in insect immunity, in addition to areas that require more research in the future.

Small RNA-sequencing reveals the involvement of microRNA-132 in benzo[a]pyrene-induced toxicity in primary human blood cells

Polycyclic aromatic hydrocarbons (PAHs) are widely distributed environmental contaminants, triggering deleterious effects such as carcinogenicity and immunosuppression, and peripheral blood mononuclear cells (PBMCs) are among the main cell types targeted by these pollutants. In the present study, we sought to identify the expression profiles and function of miRNAs, gene regulators involved in major cellular processes recently linked to environmental pollutants, in PBMC-exposed to the prototypical PAH, benzo[a]pyrene (B[a]P). Using small RNA deep sequencing, we identified several B[a]P-responsive miRNAs. Bioinformatics analyses showed that their predicted targets could modulate biological processes relevant to cell death and survival. Further studies of the most highly induced miRNA, miR-132, showed that its up-regulation by B[a]P was time- and dose-dependent and required aryl hydrocarbon receptor (AhR) activation. By evaluating the role of miR-132 in B[a]P-induced cell death, we propose a mechanism linking B[a]P-induced miR-132 expression and cytochromes P-450 (CYPs) 1A1 and 1B1 mRNA levels, which could contribute to the apoptotic response of PBMCs. Altogether, this study increases our understanding of the roles of miRNAs induced by B[a]P and provides the basis for further investigations into the mechanisms of gene expression regulation by PAHs.

Circulating miR-107 as a diagnostic biomarker of osteoporotic vertebral compression fracture increases bone formation in vitro and in vivo

AimsThis study aimed to examine the key circulating microRNAs (miRNAs) in the plasma of patients with osteoporotic vertebral compression fracture and assess their potential role as diagnostic biomarkers and explore their function in vitro and in vivo. MethodsWeighted gene co-expression network analysis (WGCNA) was applied to identify hub miRNAs for subsequent analysis. The candidate miRNAs were tested using plasma from 144 patients and the results were applied to construct receiver operating characteristic (ROC) curves to assess their diagnostic value. In addition, the function of the target miRNA was validated in MC3T3-E1 cells, human bone marrow-derived mesenchymal stromal cells (BMSCs), and an ovariectomized (OVX) mouse model. Key findingsSeven modules were obtained by WGCNA analysis. The expression levels of circulating miR-107 in the red module were significantly lower in osteoporotic patients than in healthy controls. In addition, miR-107 provided discrimination with an AUC > 85 % by ROC analyses to differentiate women osteoporosis patients from healthy controls and differentiate women osteoporotic patients with vertebral compression fractures from osteoporotic patients without vertebral compression fractures. In vitro experiments revealed that miR-107 levels were increased in osteogenically induced MC3T3-E1 cells and BMSCs and transfection with synthetic miR-107 could promote bone formation. Lastly, the bone parameters were improved by miR-107 upregulation in OVX mice. SignificanceOur findings show that circulating miR-107 plays an essential role in facilitating osteogenesis and may be a useful diagnostic biomarker and therapeutic target in osteoporosis.

Exosomal miR-133a-3p promotes the growth and metastasis of lung cancer cells following incomplete microwave ablation

Purpose Exosomal miRNAs play key roles in various biological processes such as cell proliferation, angiogenesis, migration and invasion. We explored whether exosomal miRNAs can promote local recurrence (LR) of lung tumors following incomplete microwave ablation (MWA) therapy. Methods Exosomal miRNA profiles before and after incomplete MWA in lung cancer (LC) patients with LR (n = 3) were sequenced and compared. The differentially expressed miRNAs of interest were validated in clinical samples (n = 10) and MWA-treated cells using RT-qPCR analysis. Target genes of the miRNAs were predicted and validated. The biological functions of miRNAs in proliferation, angiogenesis and metastasis of A549 cells were evaluated in vitro and in vivo. Results A total of 270 miRNAs (243 upregulated and 27 downregulated) were differentially expressed after incomplete MWA in patients with local recurrence. Upregulation of miR-133a-3p after MWA was validated in the cells and clinical samples. Cell functional experiments suggested that miR-133a-3p overexpression derived from serum exosomes increased cell viability, migration and invasion ability, tube formation activity and proliferation of A549 cells. Sirtuin 1 (SIRT1) was identified as a target gene for miR-133a-3p. Moreover, miR-133a-3p delivered by exosomes significantly promoted tumor growth, paralleled by reduced SIRT1 expression in a subcutaneous tumorigenesis animal model and increased the number of lung nodules by tail vein metastasis in vivo. Conclusion Exosomal miR-133a-3p overexpression promoted tumor growth and metastasis following MWA and could be a promising biomarker for LC recurrence after incomplete MWA.

A Compilation of the Diverse miRNA Functions in Caenorhabditis elegans and Drosophila melanogaster Development.

MicroRNAs are critical regulators of post-transcriptional gene expression in a wide range of taxa, including invertebrates, mammals, and plants. Since their discovery in the nematode, Caenorhabditis elegans, miRNA research has exploded, and they are being identified in almost every facet of development. Invertebrate model organisms, particularly C. elegans, and Drosophila melanogaster, are ideal systems for studying miRNA function, and the roles of many miRNAs are known in these animals. In this review, we compiled the functions of many of the miRNAs that are involved in the development of these invertebrate model species. We examine how gene regulation by miRNAs shapes both embryonic and larval development and show that, although many different aspects of development are regulated, several trends are apparent in the nature of their regulation.

Identification of conserved miRNAs and their targets in Jatropha curcas: an in silico approach

BackgroundMicroRNAs (miRNAs) are small endogenous RNAs with an approximate length of 18–22 nucleotides and involved in the regulation of gene expression in transcriptional or post-transcriptional levels. They were found to be associated with leaf morphogenesis, flowering time, vegetative phase change, and response to environmental cues in plants, where they act as a critical regulatory factor. The nature of high conservancy of plant miRNAs within the plant species made it possible to detect the conserved miRNAs by computational approaches. Expressed Sequence Tags (EST) based comparative genomic approaches provide advantages over wet lab approaches as it is convenient, easy to carry out and less time consuming. EST-based in silico approach can unravel new conserved miRNAs in plants, even when the complete genome sequence is not available. ResultsTo identify the novel miRNAs, a total of 46,865 ESTs from Jatropha curcas were searched for homology to all available 6746 mature miRNAs of plant eudicotyledons. Finally, we ended up with 12 novel miRNAs in Jatropha that range from 18 to 19 nucleotides where their respective precursor miRNAs had 54.11–71.76% (A + U) content. The putative miRNAs belong to 12 individual miRNA family and most of them have higher (A + U) content ranging from 47.36 to 77.77% than their respective miRNA homologs. Many of the target genes by the newly identified miRNAs were associated with plant growth and development, stress response, defense and hormone signaling, and oil synthesis pathways. ConclusionThese findings have the potential to speed up miRNA identification and expand our understanding of miRNA functions in J. curcas.

Abstract 3749: Oncogenic role of Epstein-Barr virus lnc-BARTs in EBV associated tumors

Abstract While majority of humans infected with Epstein-Barr virus (EBV) is asymptomatic for whole life, EBV is found to associate with several human cancers, including Burkitt’s lymphoma, Hodgkin’s diseases, post-transplant lymphoproliferative disorder (PTLD), nasopharyngeal carcinoma (NPC) and gastric carcinoma. Among these EBV associated tumors, EBV genome is found in 100% of NPC tumor cells. EBV establishes a latent infection in NPC cells, expressing few viral proteins, but elevated levels of non-coding RNAs transcribed from the BamHI-A region of the EBV genome, designated BamHI-A rightward transcripts (BARTs). The family of EBV BART RNAs comprises BART-microRNAs (miRNAs) and long non-coding RNAs (lnc-BARTs). While versatile functions of BART miRNAs have been revealed, little is known about the role of EBV lnc-BARTs. Here, we provided evidence to show that BARTs mRNA which derived from multiple exons of BART function as regulatory long non-coding RNA, namely lnc-BARTs, in modulating the core network for maintaining EBV latency and promoting NPC oncogenesis through epigenetic mechanisms. Our results showed that the apoptosis rate of NPC cell lines with knockdown of EBV lnc-BARTs was significantly increased, suggesting that lnc-BARTs have an anti-apoptotic effect in EBV associated tumors. MS analysis was performed to identify host factors which interact with EBV lnc-BARTs in NPC cells. Lnc-BARTs were shown to directly interact with several transcriptional regulators, including BRD4 and SC35. Notably, RNA-FISH assays demonstrated that lnc-BARTs co-localize with BRD4 and SC35 complexes in nuclear speckles, with these complexes being disrupted by treatment with JQ1, a BRD4 competitive inhibitor. RNA immunoprecipitation and RNA pulldown assays confirmed that lnc-BARTs bind to BRD4. ATAC sequencing analysis and transcriptome analysis further demonstrated that knockdown of BARTs in the EBV-harboring NPC cell line, C666-1, resulted in globally reduced chromatin accessibility downregulation of oncogenes like MYC and BCL2. In addition, ChIP sequencing analysis revealed that lnc-BARTs interfere PolII phosphorylation on promoters of genes. Our findings suggest that EBV lnc-BARTs are involved in epigenetic modulation of host gene expression through functional interaction with elongation regulatory machinery to maintain EBV latency and drive tumorigenesis in NPC. Citation Format: LIU JIAYAN, Bobo Wing-Yee Mok, Songtao He, Honglin Chen. Oncogenic role of Epstein-Barr virus lnc-BARTs in EBV associated tumors. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3749.

Abstract 3746: Dynamic characterization of small RNAs in non small cell lung cancer exosomes under immune-checkpoint inhibitor treatments

Abstract Immunotherapy based on Immune Checkpoint blockade (ICB) has become a significant therapeutic option for advanced Non Small Cell Lung Cancer (NSCLC) patients. However, there is an urgent need to find novel biomarkers that to reliably stratify good responders to immunotherapy. Currently, the available biomarkers are not specific enough. Exosomes are small membrane vesicles with sizes of 30-100 nm secreted by most cell types including cancer cells. Exosomes operate as an intercellular communication system by sending proteins, mRNA and miRNAs among other relevant RNA molecules. Exosomes enriched with miRNAS are involved in proliferation, differentiation, maduration and immune cell activation. Moreover, in cancer cells miRNA and other small RNA molecule expressions are dysregulated. Exosomes produced from cancer patient's plasma have been shown to be accurate diagnostic tools for the disease. In this study we profiled miRNAs and other small RNA cargo by exosome of plasma samples from 77 Non Small Cell Lung Cancer (NSCLC) metastatic patients before and after the first cycle of immunotherapy to evaluate the potentiality of predicting response to immunotherapy. We perform exosomes together with RNA isolation and small RNAseq sequencing from plasma samples before and after the first ICB cycle. Two independent softwares were used to identify small RNAs (RNAtoolbox and mirMaster). Prior ICB treatment we did not find differentially expressed miRNAs or other small RNA between good and bad responders. Interestingly we identified 12 exosomal miRNA differentially expressed between good and bad responders after the first cycle of ICB. Intriguingly, levels of miR-134-5p, miR-142-3p, miR-143-3p among others previously associated with NSCLC were found to be considerably higher in the good responder group than the bad responder group. Regarding other smallRNA molecules we observed a great variety and variability of piRNA, rRNA, scaRNA, lncRNA, snoRNA, snRNA, miscRNA and circRNA. To address the function of miRNA and other differentially expressed RNA molecules, we consulted KEGG, GO and Reactome for gene regulatory networks. Interestingly, KEGG results show pathways in cancer as top hit and Reactome highlight Immune System and cancer hits. In conclusion, we observed that patients that have favorable response to ICB have distinctive plasma exosomal miRNA patterns that could be used as possible biomarkers for predicting the effectiveness of immunotherapy in advanced NSCLC patients Citation Format: Maria Garrido-Barros, Javier Oliver, Juan Luis Onieva, Beatriz Martinez-Galvez, Jaime Duddelman, Antonio Rueda, Elisabeth Perez, Emilio Alba, Inmaculada Ramos, Juan Zafra, Manuel Cobo, Isabel Barragán. Dynamic characterization of small RNAs in non small cell lung cancer exosomes under immune-checkpoint inhibitor treatments. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3746.

MiR-34a-5p as molecular hub of pathomechanisms in Huntington’s disease

BackgroundAlthough a pivotal role of microRNA (miRNA, miR) in the pathogenesis of Huntington’s disease (HD) is increasingly recognized, the molecular functions of miRNAs in the pathomechanisms of HD await further elucidation. One of the miRNAs that have been associated with HD is miR-34a-5p, which was deregulated in the mouse R6/2 model and in human HD brain tissues.MethodsThe aim of our study was to demonstrate interactions between miR-34a-5p and HD associated genes. By computational means we predicted 12 801 potential target genes of miR-34a-5p. An in-silico pathway analysis revealed 22 potential miR-34a-5p target genes in the KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway “Huntington’s disease”.ResultsUsing our high-throughput miRNA interaction reporter assay (HiTmIR) we identified NDUFA9, TAF4B, NRF1, POLR2J2, DNALI1, HIP1, TGM2 and POLR2G as direct miR-34a-5p target genes. Direct binding of miR-34a-5p to target sites in the 3’UTRs of TAF4B, NDUFA9, HIP1 and NRF1 was verified by a mutagenesis HiTmIR assay and by determining endogenous protein levels for HIP1 and NDUFA9. STRING (Search Tool for the Retrieval of Interacting Genes/Proteins) analysis identified protein–protein interaction networks associated with HD like “Glutamine Receptor Signaling Pathway” and “Calcium Ion Transmembrane Import Into Cytosol”.ConclusionOur study demonstrates multiple interactions between miR-34a-5p and HD associated target genes and thereby lays the ground for future therapeutic interventions using this miRNA.

MP20-10 ENZALUTAMIDE INCREASES PROSTATE CANCER (PCa) CELL INVASION YET DECREASES BLADDER CANCER (BCa) CELL INVASION VIA DIFFERENTIALLY REGULATING THE AR/circRNA-ARC1/miR-125b-2-3p OR MiR-4736/PPARγ/MMP-9 SIGNALS

You have accessJournal of UrologyCME1 Apr 2023MP20-10 ENZALUTAMIDE INCREASES PROSTATE CANCER (PCa) CELL INVASION YET DECREASES BLADDER CANCER (BCa) CELL INVASION VIA DIFFERENTIALLY REGULATING THE AR/circRNA-ARC1/miR-125b-2-3p OR MiR-4736/PPARγ/MMP-9 SIGNALS Gang Deng, Yixi Hu, Yin Sun, Jean Joseph, Shuyuan Yeh, Edward M. Messing, and Chawnshang Chang Gang DengGang Deng More articles by this author , Yixi HuYixi Hu More articles by this author , Yin SunYin Sun More articles by this author , Jean JosephJean Joseph More articles by this author , Shuyuan YehShuyuan Yeh More articles by this author , Edward M. MessingEdward M. Messing More articles by this author , and Chawnshang ChangChawnshang Chang More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003245.10AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Androgen-deprivation therapy (ADT) is a standard treatment to prevent and shrink PCa growing. However, some patients undergoing ADT may finally develop to hormone-insensitive PCa. The underlying mechanisms haven't been fully elucidated. Here we found ADT-Enz led to increased PCa cell invasion, yet decreased BCa cell invasion. Our goal is to 1.reveal mechanisms of Enz induced hormone-insensitive PCa and find a potential combination therapy. 2. reveal mechanisms of ADT role in BCa and provide an evidence of applying ADT in BCa. METHODS: The human PCa and BCa cells: C4-2, CWR22Rv1, T24 and TCC-SUP were used. Lentiviral plasmids were used to generate gene engineering tools. qPCR and Western blot were used to detect gene expressions. Invasion assay were applied to determine cancer cell invasion capability. Protein-DNA binding complexes were detected by Chromatin immunoprecipitation (ChIP) assays. PPARGC1B/PDK1 3′UTR regions were cloned into the psiCHECKTM-2 vector to assay the miRNA functions. Preclinical mouse PCa model was used to evaluate the anti-cancer efficacy of Enz and circRNA-ARC1 blockage. RESULTS: Mechanistic dissection revealed that suppressing androgens/AR signals could result in differential alterations of the selective circular RNAs (circRNAs) as a result of differential endogenous AR transcription. A negative autoregulation in PCa, yet a positive autoregulation in BCa, as a result of differential binding of AR to different androgen-response elements (AREs) and a discriminating histone H3K4 methylation. Further mechanistic studies indicated that AR-encoded circRNA-ARC1 might sponge the availability of the miR-125b-2-3p and/or miR-4736 to impact the metastasis-related PPARγ/MMP-9 signals. The preclinical mouse model confirms in vitro cell lines data, showing that Enz treatment could increase PCa metastasis, which can be suppressed after iknockdown of circRNA-ARC1. Together, these results demonstrate that antiandrogen therapy with Enz treatment may differentially lead to promoting PCa cell invasion, yet decreasing BCa cell invasion. CONCLUSIONS: Our study is the first to reveal ADT-Enz treatment can promote PCa Cell Invasion yet decrease BCa cell Invasion via differentially regulating the AR/circRNA-ARC1/miR-125b-2-3p or MiR-4736/PPARγ/MMP-9 Signals. Furthermore, our findings may help in development of novel therapeutic approaches to increase the Enz efficacy with less adverse effects in patients with PCa, and providing an evidence of applying ADT in BCa. Source of Funding: This work was partially supported by URMC Urology Department Research fund and George H. Whipple Professorship Endowment © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e279 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Gang Deng More articles by this author Yixi Hu More articles by this author Yin Sun More articles by this author Jean Joseph More articles by this author Shuyuan Yeh More articles by this author Edward M. Messing More articles by this author Chawnshang Chang More articles by this author Expand All Advertisement PDF downloadLoading ...

The potential role of plasma miR-4301 in PM2.5 exposure-associated lung function reduction

The effect of PM2.5 exposure on lung function reduction has been well-documented, but the underlying mechanism remains unclear. MiR-4301 may be involved in regulating pathways related to lung injury/repairment, and this study aimed to explore the potential role of miR-4301 in PM2.5 exposure-associated lung function reduction. A total of 167 Wuhan community nonsmokers were included in this study. Lung function was measured and personal PM2.5 exposure moving averages were evaluated for each participant. Plasma miRNA was determined by real-time polymerase chain reaction. A generalized linear model was conducted to assess the relationships among personal PM2.5 moving average concentrations, lung function, and plasma miRNA. The mediation effect of miRNA on the association of personal PM2.5 exposure with lung function reduction was estimated. Finally, we performed pathway enrichment analysis to predict the underlying pathways of miRNA in lung function reduction from PM2.5 exposure. We found that each 10 μg/m3 increase in the 7-day personal PM2.5 moving average concentration (Lag0-7) was related to a 46.71 mL, 1.15%, 157.06 mL/s, and 188.13 mL/s reductions in FEV1, FEV1/FVC, PEF, and MMF, respectively. PM2.5 exposure was negatively associated with plasma miR-4301 expression levels in a dose‒response manner. Additionally, each 1% increase in miR-4301 expression level was significantly associated with a 0.36 mL, 0.01%, 1.14 mL/s, and 1.28 mL/s increases in FEV1, FEV1/FVC, MMF, and PEF, respectively. Mediation analysis further revealed that decreased miR-4301 mediated 15.6% and 16.8% of PM2.5 exposure-associated reductions in FEV1/FVC and MMF, respectively. Pathway enrichment analyses suggested that the wingless related-integration site (Wnt) signaling pathway might be one of the pathways regulated by miR-4301 in the reduction of lung function from PM2.5 exposure. In brief, personal PM2.5 exposure was negatively associated with plasma miR-4301 or lung function in a dose‒response manner. Moreover, miR-4301 partially mediated the lung function reduction associated with PM2.5 exposure.

Recent advances in extracellular vesicles in gastrointestinal cancer and lymphoma.

Extracellular vesicles (EVs) are intercellular communication agents that transfer microRNAs (miRNAs), other non-coding RNAs (ncRNAs), messenger RNAs (mRNAs), proteins, lipids, metabolites, and other molecules from donor cells (e.g., cancer cells) to recipient cells (e.g., stromal cells). In 2007, miRNAs were reported to be abundant among the ncRNAs present in EVs. Since then, many studies have investigated the functions of miRNAs and have attempted to apply these molecules to aid in the diagnosis and treatment of cancer. Research on EVs has expanded, particularly in the field of cancer, because cancer cells heavily secrete EVs. The cargo of these EVs, especially those in small EVs, such as exosomes, is assumed to work cooperatively and significantly in the tumor microenvironment and to promote metastasis. In this review, we first summarize recent studies on EVs in gastrointestinal cancer and highlight studies on human satellite II RNAs, which are a type of ncRNA found in EVs that possess repetitive sequences. Second, since several recent studies have revealed that phospholipids, which are components of EV membranes, play important roles in intercellular communication and the generation of lipid mediators in the tumor microenvironment, we review the reported roles of these molecules and discuss their potential use in the design of new cancer treatments.

Granulosa cell-derived miR-379-5p regulates macrophage polarization in polycystic ovarian syndrome.

Polycystic ovarian syndrome (PCOS) is associated with hyperandrogenemia and ovarian antral follicle growth arrest. We have previously demonstrated that androgen-induced exosomal release of miR-379-5p (miR379) from preantral follicle granulosa cells increases the proliferation of target cells via phosphoinositide-dependent kinase 1 (PDK1) upregulation. Androgen also increases inflammatory M1 macrophage abundance, but reduces anti-inflammatory M2 polarization in rat antral and preovulatory follicles. However, the role of small extracellular vesicles (sEVs; also known as exosomes) secretion in determining the cellular content and function of miRNAs in exosome-receiving cells is largely unknown. Our objectives were to determine: 1) the regulatory role of granulosa cells (GC)-derived exosomal miR379 on macrophage polarization and ovarian inflammation; 2) whether miR379-induced M1 polarization regulates GC proliferation; and 3) if this regulated process is follicular stage-specific. Compared with non-PCOS subjects, PCOS subjects had a higher M1/M2 ratio, supporting the concept that PCOS is an inflammatory condition. Ovarian overexpression of miR379 increased the number of M1 macrophages and the M1/M2 ratio in preantral follicles specifically. Transfection of macrophages with a miR379 mimic reduced the cellular content of PDK1 and induced M0→M1 polarization; whereas its inhibitor polarized M0→M2. Conditioned media from macrophages transfected with miR379 mimic and follicular fluid from PCOS subjects had higher galectin-3 content, a pro-inflammatory cytokine which specifically suppresses human antral follicle GC proliferation. These results indicate that miR379 inhibits M2 macrophage polarization, a condition which suppresses GC proliferation in a follicle stage-dependent manner, as exhibited in PCOS.

Exosomal microRNAs from PBMCs stimulated with culprit drugs enhanced keratinocyte cell death in Stevens-Johnson syndrome/toxic epidermal necrolysis.

Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) and drug reactions with eosinophilia and systemic symptoms (DRESS) are both severe cutaneous adverse reactions. Keratinocyte death is much more prominent in SJS/TEN compared to DRESS. This study aimed to investigate the role of exosomal miRNAs on keratinocyte death in SJS/TEN. Peripheral blood mononuclear cells (PBMCs) from SJS/TEN and DRESS patients were stimulated with the culprit drugs. The exosomes released in cell supernatants were co-incubated with HaCaT cells to study the cytotoxic effects on keratinocytes. Exosomal miRNA sequencing analysis was performed to compare the expression patterns between SJS/TEN and DRESS subjects. HaCaT cells were then transfected with miRNA mimics and inhibitors to explore the functions of miRNAs on keratinocyte cell death. Cytotoxic effects of PBMC-derived exosomes on keratinocytes were demonstrated in SJS/TEN and could be neutralized with exosome inhibitors. Cytotoxic effects of PBMC-derived exosomes from SJS/TEN subjects were higher after incubating PBMCs with the culprit drugs than those incubating with irrelevant drugs and unstimulated controls. The sequencing data revealed differential expressions of 61 exosomal miRNAs between SJS/TEN and DRESS. Exosomal miR-4488 was upregulated while miR-486-5p, miR-96-5p and miR-132-3p were downregulated in SJS/TEN compared to DRESS as determined by quantitative real-time PCR. The increased percentage of apoptotic cells upon transfection of HaCat cells was 36.3% and 34.9% with miR-4488 mimic and miR-96-5p inhibitor, respectively. This study illustrated the regulatory functions of exosomal miRNAs in controlling keratinocyte death in SJS/TEN. Exosome inhibitors might have a therapeutic role in SJS/TEN.

KRAS Hijacks the miRNA Regulatory Pathway in Cancer.

Extensive studies have focused on the misregulation of individual miRNAs in cancer. More recently, mutations in the miRNA biogenesis and processing machinery have been implicated in several malignancies. Such mutations can lead to global miRNA misregulation, which may promote many of the well-known hallmarks of cancer. Interestingly, recent evidence also suggests that oncogenic Kristen rat sarcoma viral oncogene homolog (KRAS) mutations act in part by modulating the activity of members of the miRNA regulatory pathway. Here, we highlight the vital role mutations in the miRNA core machinery play in promoting malignant transformation. Furthermore, we discuss how mutant KRAS can simultaneously impact multiple steps of miRNA processing and function to promote tumorigenesis. Although the ability of KRAS to hijack the miRNA regulatory pathway adds a layer of complexity to its oncogenic nature, it also provides a potential therapeutic avenue that has yet to be exploited in the clinic. Moreover, concurrent targeting of mutant KRAS and members of the miRNA core machinery represents a potential strategy for treating cancer.

Target Landscape of Conserved Plant MicroRNAs and the Complexities of Their Ancient MicroRNA-Binding Sites.

In plants, microRNA (miRNA)-target interactions (MTIs) require high complementarity, a feature from which bioinformatic programs have predicted numerous and diverse targets for any given miRNA, promoting the idea of complex miRNA networks. Opposing this is a hypothesis of constrained miRNA specificity, in which functional MTIs are restricted to the few targets whose required expression output is compatible with the expression of the miRNA. To explore these opposing views, the bioinformatic pipeline Targets Ranked Using Experimental Evidence was applied to strongly conserved miRNAs to identity their high-evidence (HE) targets across species. For each miRNA family, HE targets predominantly consisted of homologs from one conserved target gene family (primary family). These primary families corresponded to the known canonical miRNA-target families, validating the approach. Very few additional HE target families were identified (secondary family), and if so, they were likely functionally related to the primary family. Many primary target families contained highly conserved nucleotide sequences flanking their miRNA-binding sites that were enriched in HE homologs across species. A number of these flanking sequences are predicted to form conserved RNA secondary structures that preferentially base pair with the miRNA-binding site, implying that these sites are highly structured. Our findings support a target landscape view that is dominated by the conserved primary target families, with a minority of either secondary target families or non-conserved targets. This is consistent with the constrained hypothesis of functional miRNA specificity, which potentially in part is being facilitated by features beyond complementarity.

Stress‐sensitive dynamics of miRNAs and Elba1 in Drosophila embryogenesis

Early‐life stress can result in life‐long effects that impact adult health and disease risk, but little is known about how such programming is established and maintained. Here, we show that such epigenetic memories can be initiated in the Drosophila embryo before the major wave of zygotic transcription, and higher‐order chromatin structures are established. An early short heat shock results in elevated levels of maternal miRNA and reduced levels of a subgroup of zygotic genes in stage 5 embryos. Using a Dicer‐1 mutant, we show that the stress‐induced decrease in one of these genes, the insulator‐binding factor Elba1, is dependent on functional miRNA biogenesis. Reduction in Elba1 correlates with the upregulation of early developmental genes and promotes a sustained weakening of heterochromatin in the adult fly as indicated by an increased expression of the PEV wm4h reporter. We propose that maternal miRNAs, retained in response to an early embryonic heat shock, shape the subsequent de novo heterochromatin establishment that occurs during early development via direct or indirect regulation of some of the earliest expressed genes, including Elba1.

Erythrocyte-Derived microRNAs: Emerging Players in Cardiovascular and Metabolic Disease.

Recent studies have demonstrated a novel function of red blood cells (RBCs) beyond their classical role as gas transporters, that is, RBCs undergo functional alterations in cardiovascular and metabolic disease, and RBC dysfunction is associated with hypertension and the development of cardiovascular injury in type 2 diabetes, heart failure, preeclampsia, familial hypercholesterolemia/dyslipidemia, and COVID-19. The underlying mechanisms include decreased nitric oxide bioavailability, increased arginase activity, and reactive oxygen species formation. Of interest, RBCs contain diverse and abundant micro (mi)RNAs. microRNA expression pattern in RBCs reflects the expression in the whole blood, serum, and plasma. microRNA levels in RBCs have been found to be altered in various cardiovascular and metabolic diseases, which contributes to the development of cardiovascular complications. Evidence has shown that RBC-derived miRNAs interact with the cardiovascular system via extracellular vesicles and argonaute RISC catalytic component 2 as carriers. Alteration of RBC-to-vascular communication via miRNAs may serve as potential disease mechanism for vascular complications. The present review summarizes RBCs and their released miRNAs as potential mediators of cardiovascular injury. We further focus on the possible mechanisms by which RBC-derived miRNAs regulate cardiovascular function. A better understanding of the function of RBC-derived miRNAs will increase insights into the disease mechanism and potential targets for the treatment of cardiovascular complications.