miRNAsong: a web-based tool for generation and testing of miRNA sponge constructs in silico

MicroRNA mechanisms instructing Purkinje cell specification

MicroRNAs (miRNAs) are critical for brain development; however, if, when, and how miRNAs drive neuronal subtype specification remains poorly understood. To address this, we engineered technologies with vastly improved spatiotemporal resolution that allow the dissection of cell-type-specific miRNA-target networks. Fast and reversible miRNA loss of function showed that miRNAs are necessary for Purkinje cell (PC) differentiation, which previously appeared to be miRNA independent, and identified distinct critical miRNA windows for dendritogenesis and climbing fiber synaptogenesis, structural features defining PC identity. Using new mouse models that enable miRNA-target network mapping in rare cell types, we uncovered PC-specific post-transcriptional programs. Manipulation of these programs revealed that the PC-enriched miR-206 and targets Shank3, Prag1, En2, and Vash1, which are uniquely repressed in PCs, are critical regulators of PC-specific dendritogenesis and synaptogenesis, with miR-206 knockdown and target overexpression partially phenocopying miRNA loss of function. Our results suggest that gene expression regulation by miRNAs, beyond transcription, is critical for neuronal subtype specification.

The potential regulatory role of non-coding RNAs in mifepristone-induced masculinization in Takifugu rubripes gonads

BACKGROUND

The regulatory roles of non-coding RNAs (ncRNAs) during sex differentiation in teleosts have received widespread attention recently. Mifepristone (RU486, a progesterone antagonist), which acts as an endocrine disruptor, can affect reproduction and sex differentiation in teleosts.

RESULTS

The expression of ncRNAs in the gonads of tiger puffer (Takifugu rubripes) during RU486 (500 µg/g diet) induced masculinization process was examined by RNA-sequencing. A total of 4,381 long non-coding RNAs (lncRNAs), 309 circular RNAs (circRNAs), and 1,020 microRNAs (miRNAs) were identified. The expression of 41 differentially expressed (DE) lncRNAs and 20 DE miRNAs, which showed sexual dimorphic expression patterns in genetic female gonads in the control group (C-XX) vs. genetic male gonads in the control group (C-XY), were altered in genetic female gonads in the RU486 treated group (RU-XX). The genes targeted by DE ncRNAs were mainly enriched in sex-related pathways, such as calcium signaling, ovarian steroidogenesis, and cortisol synthesis and secretion. The results of co-expression and competing endogenous RNA (ceRNA) network analysis indicated that miRNAs (e.g., miR-205-z and fru-miR-122) and lncRNAs (including XR_003890915.1 and XR_003885862.1) may have pivotal roles, and lncRNAs (including XR_003890295.1, MSTRG.11750.1, and XR_003888827.1) may act as miRNA sponges, involved in the competition between miRNAs and sex-related genes during tiger puffer masculinization process. Dual luciferase reporter assay results identified that ovarian steroidogenesis related gene hsd17b1 is a downstream target of fru-miR-122. The expression of 4 lncRNAs, 4 circRNAs, and 6 miRNAs were validated by qPCR, indicating the accuracy and dependability of RNA-Seq.

CONCLUSIONS

This study provided the evidence that ncRNAs may participate in RU486-induced masculinization in T. rubripes, and may enhance our understanding of the regulatory network of sex differentiation in fugu.

Therapeutic Applications of Poly-miRNAs and miRNA Sponges

MicroRNAs (miRNAs) are small, non-coding RNA molecules that play crucial roles in regulating gene expression, and their dysregulation is implicated in various human diseases. Over the years, several research groups have identified miRNAs as promising therapeutic targets for intervention. Therapeutic strategies involve either overexpression or knockdown of specific miRNAs. This review aims to provide a comprehensive overview of synthetic poly-miRNAs and miRNA sponges, highlighting their therapeutic applications. It begins with an introduction to miRNAs and their role in human diseases, followed by a detailed discussion on synthetic poly-miRNAs and miRNA sponges by exploring their application in cardiovascular, inflammatory, autoimmune, and metabolic disorders, as well as in cancer therapy. Additionally, strategies for targeted delivery, challenges, and limitations of these therapies are addressed.

MicroRNAs as Sensitizers of Tyrosine Kinase Inhibitor Resistance in Cancer: Small Molecule Partnerships

Tyrosine kinase inhibitors (TKIs) have revolutionized cancer treatments by being less toxic and improving the survival of cancer patients. The greatest challenge to their success is the resistance exhibited by cancer patients. However, the potential of microRNAs (miRNAs) for sensitizing molecules to TKIs has been well recognized, with several reports publishing promising results. Nonetheless, this therapeutic window faces challenges and several often-overlooked limitations. One of the most fundamental challenges is selecting the optimal miRNA candidates for clinical trials, as miRNAs are promiscuous and regulate hundreds of targets. In this review, we describe how miRNAs enhance sensitivity to TKIs across various types of cancer. We highlight several challenges and limitations in achieving a successful collaboration between small molecules (TKIs-miRNAs). Our focus is on proposing a workflow to select the most suitable miRNA candidate, recommending several available bioinformatics tools to develop a successful therapeutic partnership between TKIs and miRNAs. We hope that this initial proposal will provide valuable support for future research.

Comparative genomics profiling of Citrus species reveals the diversity and disease responsiveness of the GLP pangenes family

Citrus is an important nutritional fruit globally; however, its yield is affected by various stresses. This study presents the draft pangenome of Citrus, developed using 11 species to examine their genetic diversity and identify members of the germin-like proteins (GLPs) gene family involved in disease responsiveness. The developed sequence-based pangenome contains 954 Mb sequence and 74,755 genes. The comparative genomics analysis revealed the presence-absence variations (PAVs) among the Citrus genomes and species-specific protein-coding genes. Gene-based pangenome analysis revealed 4,936 new genes missing in the reference genome and highlighted the core and shell genes with putative functions in stress regulation. The pangenome-wide identification of GLP gene family members indicated the intraspecies diversity among the members across 11 genomes by analyzing their gene structure, motifs, and chromosomal distribution patterns. The synteny and evolutionary constraints analyses of Citrus GLPs provide detailed evidence of their evolutionary conservation and divergence. Further, the interaction, functional enrichment, and promoter analysis revealed their involvement in abiotic-, biotic-stress, signaling, and development-related pathways. The expression patterns of C. sinensis GLPs were studied in Huanglongbing (HLB) and Citrus canker disease. Several genes including CsGLPs1-2 and CsGLPs8-4 showed changes in expression patterns under both disease conditions. The qRT-PCR analysis revealed that these two genes were highly expressed in leaves infected with HLB disease across seven HLB-tolerant and susceptible citrus species. This Citrus pangenome and pangenes family study offers a comprehensive resource and new insights into the structural and functional diversity, identifying candidate genes that are important for future research to understand the stress-responsive mechanisms in Citrus.

A miR-219-5p-bmal1b negative feedback loop contributes to circadian regulation in zebrafish

MicroRNAs post-transcriptionally regulate gene expression and contribute to numerous life processes, including circadian rhythms. However, whether miRNAs contribute to zebrafish circadian regulation has not yet been investigated. Here, we showed that mature miR-219-5p, and its three pre-miRNAs, mir-219-1, mir-219-2, and mir-219-3, are rhythmically expressed primarily in Tectum opticum (TeO), Corpus cerebelli (CCe), and Crista cerellaris (CC) of the zebrafish brain. While mir-219-1 and mir-219-2 are regulated by the circadian clock through the E-like box, mir-219-3 is regulated by light via the D-box. Deleting mir-219-1, mir-219-2, or mir-219-3 individually or knocking down miR-219-5p all results in a shortened period of locomotor rhythms and up-regulation of bmal1b. RIP assays with Ago2 and miRNA pull-down assays show that miR-219-5p binds to bmal1b in the RISC. Cell transfection and in Vivo assays show that miR219-5p inhibits bmal1b through binding to its 3'UTR. Further, transcriptome analysis of miR-219-5p knockdown zebrafish adult brain reveals possible roles of miR-219-5p in phototransduction and neuroactive ligand-receptor interaction. Together, our findings demonstrate that mir-219-1, mir-219-2, and mir-219-3 are controlled directly by the circadian clock; and in turn, miR-219-5p contributes to circadian regulation by targeting bmal1b, highlighting a miR-219-5p-bmal1b negative feedback loop in the zebrafish circadian circuit.

Molecular mechanisms of sulforaphane in Alzheimer's disease: insights from an in-silico study

This study was to identify the molecular pathways that may explain sulforaphane's Alzheimer's disease (AD) benefits using multiple advanced in silico approaches. We found that sulforaphane regulates 45 targets, including TNF, INS, and BCL2. Therefore, it may help treat AD by reducing neuroinflammation, insulin resistance, and apoptosis. The important relationships were co-expression and pathways. 45 targets were linked to the midbrain, metabolite interconversion enzymes, 14q23.3 and 1q31.1 chromosomes, and modified residues. "Amyloid precursor protein catabolic process", "regulation of apoptotic signaling pathway", and "positive regulation of nitric oxide biosynthetic process" were the main pathways, while NFKB1, SP1, RELA, hsa-miR-17-5p, hsa-miR-16-5p, and hsa-miR-26b-5p were transcription factors and miRNAs implicated in sulforaphane In AD treatment, miRNA sponges, dexibuprofen, and sulforaphane may be effective. Furthermore, its unique physicochemical, pharmacokinetic, and biological qualities make sulforaphane an effective AD treatment, including efficient gastrointestinal absorption, drug-like properties, absence of CYP450 enzyme inhibition, not being a substrate for P-glycoprotein, ability to cross the blood-brain barrier, glutathione S-transferase substrate, immunostimulant effects, and antagonistic neurotransmitter effects. Sulforaphane is a promising compound for AD management. Further work is needed to elucidate its therapeutic effects based on our findings, including genes, miRNAs, molecular pathways, and transcription factors.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40203-024-00267-4.

MiR-17∼92 is involved in NF-κB activation via targeting the ubiquitin-editing proteins to mediate RIP1 complex polyubiquitinations in ABC-DLBCL

Activated B-cell-like diffuse large B-cell lymphoma (ABC-DLBCL) is an aggressive lymphoma characterized by constitutive NF-κB activation, but whether miR-17∼92 contributes to this activation remains unclear. Herein, we sought to evaluate the role of miR-17∼92 in the process of NF-κB activation in ABC-DLBCL. We found that the expression of miR-17∼92 primary transcript was positively correlated with NF-κB activity, miR-17∼92 activated the NF-κB signaling in ABC-DLBCL, and its over-expression promoted ABC-DLBCL cell growth, accelerated cell G1 to S phase transition and enhanced cell resistance to NF-κB inhibitor. Importantly, miR-17∼92 promoted NF-κB activation through directly targeting multiple ubiquitin-editing regulators to lead to increase the K63-linked polyubiquitination and decrease the K48-linked polyubiquitination of RIP1 complex in ABC-DLBCL. We further found that miR-17∼92 selectively activated IκB-α and NF-κB p65 but not NF-κB p52/p100, and high miR-17∼92 expression was also associated with poorer outcome in ABC-DLBCL patients. Overall, our results showed that miR-17∼92 selectively activated the canonical NF-κB signaling via targeting ubiquitin-editing regulators to lead to constitutively NF-κB activation and poorer outcome in ABC-DLBCL. These findings uncovered an innovative function of miR-17∼92 and previously unappreciated regulatory mechanism of NF-κB activation in ABC-DLBCL. Targeting miR-17∼92 may thus provide a novel bio-therapeutic strategy for ABC-DLBCL patients.

Hypoxia promotes metastasis by relieving miR-598-3p-restricted glycolysis in gastric cancer

The activation of glycolysis, particularly in the context of reprogrammed energy metabolism, is increasingly recognized as a significant characteristic of cancer. However, the precise mechanisms by which glycolysis is promoted in metastatic gastric cancer cells under normal oxygen conditions remain poorly understood. MicroRNAs (miRNAs) play a crucial role in the development of malignant phenotypes in gastric cancer. Nevertheless, our understanding of the specific involvement of miRNAs in hypoxia-induced metabolic shifting and the subsequent metastatic processes is limited. Hypoxia-induced downregulation of miR-598-3p mechanistically leads to the upregulation of RMP and IGF1r, thereby promoting glycolysis. Either overexpression of miR-598-3p or R406 treatment effectively suppresses the metastasis of gastric cancer cells both in vitro and in vivo. Collectively, the depletion of miR-598-3p alters glucose metabolism from oxidative phosphorylation to glycolysis, thereby exacerbating the malignancy of gastric cancer cells. The present findings indicate a potential target for the development of therapeutics against gastric cancers with increased miR-598-3p expression.

Drug regulation of microRNA

The scientific review provides the mechanisms of drug regulation of microRNA in the human body. To write the article, information was searched using Scopus, Web of Science, MEDLINE, PubMed, Google Scholar, Embase, Global Health, The Cochrane Library databases. To restore the reduced functional activity of microRNAs, replacement therapy is used, with modified synthetic analogs of endogenous microRNAs, and drugs that enhance the production of the body’s own microRNAs. The authors state that numerous studies have confirmed the effectiveness of miRNA replacement therapy. It is known that there are several groups of drugs among miRNA inhibitors: anti-miRNA oligonucleotides, miRNA traps, miRNA mimics that prevent miRNA binding; peptide nucleic acids, small-molecule inhibitors. The authors suggest that the expression of drug-metabolizing enzymes is controlled by nuclear receptors and transcription factors, epigenetic regulation such as DNA methylation and histone acetylation, and post-translational modification. It is emphasized that ursodeoxycholic acid modulates the expression of some miRNAs. It is known that probiotic bacteria can modulate the expression level of miRNA genes. The use of probiotics is accompanied by a change in the expression of nume­rous genes of the body involved in the regulation of the inflammatory response, allergic reactions, metabolism and other biological processes. Thus, modern science is intensively studying the potential of using drugs that restore miRNA content or inhibit miRNA acti­vity for the therapy of miRNA-dependent conditions. The results of scientific research confirmed the therapeutic effect of ursodeoxycholic acid and probiotic preparations due to the effect on the acti­vity of miRNA generation in hepatobiliary diseases. Therefore, the introduction into clinical practice of drugs than can modulate the content and expression of specific miRNAs will certainly open new perspectives in the treatment of patients with hepatobiliary diseases.

Understanding the multifaceted role of miRNAs in Alzheimer's disease pathology

Small non-coding RNAs (miRNAs) regulate gene expression by binding to mRNA and mediating its degradation or inhibiting translation. Since miRNAs can regulate the expression of several genes, they have multiple roles to play in biological processes and human diseases. The majority of miRNAs are known to be expressed in the brain and are involved in synaptic functions, thus marking their presence and role in major neurodegenerative disorders, including Alzheimer's disease (AD). In AD, amyloid beta (Aβ) plaques and neurofibrillary tangles (NFTs) are known to be the major hallmarks. The clearance of Aβ and tau is known to be associated with miRNA dysregulation. In addition, the β-site APP cleaving enzyme (BACE 1), which cleaves APP to form Aβ, is also found to be regulated by miRNAs, thus directly affecting Aβ accumulation. Growing evidences suggest that neuroinflammation can be an initial event in AD pathology, and miRNAs have been linked with the regulation of neuroinflammation. Inflammatory disorders have also been associated with AD pathology, and exosomes associated with miRNAs are known to regulate brain inflammation, suggesting for the role of systemic miRNAs in AD pathology. Several miRNAs have been related in AD, years before the clinical symptoms appear, most of which are associated with regulating the cell cycle, immune system, stress responses, cellular senescence, nerve growth factor (NGF) signaling, and synaptic regulation. Phytochemicals, especially polyphenols, alter the expression of various miRNAs by binding to miRNAs or binding to the transcriptional activators of miRNAs, thus control/alter various metabolic pathways. Awing to the sundry biological processes being regulated by miRNAs in the brain and regulation of expression of miRNAs via phytochemicals, miRNAs and the regulatory bioactive phytochemicals can serve as therapeutic agents in the treatment and management of AD.

tRNA-derived small RNAs are embedded in the gene regulatory network instructing Drosophila metamorphosis

A class of noncoding RNAs, referred to as tsRNAs, is emerging with a potential to exert a new layer in gene regulation. These RNAs are breakdown products of tRNAs, either through active processing or passive cleavage or both. Since tRNAs are part of the general machinery for translation, their expression levels and activities are tightly controlled, raising the possibility that their breakdown products, tsRNAs, may provide a link between the overall translational status of a cell to specific changes in gene regulatory network. We hypothesize that Drosophila pupation, being a special developmental stage during which there is a global limitation of nutrients, represents a system in which such a link may readily reveal itself. We show that specific tsRNAs indeed show a dynamic accumulation upon entering the pupal stage. We describe experiments to characterize the mode of tsRNA action and, through the use of such gained knowledge, conduct a genome-wide analysis to assess the functions of dynamically expressed tsRNAs. Our results show that the predicted target genes are highly enriched in biological processes specific to this stage of development including metamorphosis. We further show that tsRNA action is required for successful pupation, providing direct support to the hypothesis that tsRNAs accumulated during this stage are critical to the gene expression program at this stage of development.

Role of ciliopathy protein TMEM107 in eye development: insights from a mouse model and retinal organoid

Primary cilia are cellular surface projections enriched in receptors and signaling molecules, acting as signaling hubs that respond to stimuli. Malfunctions in primary cilia have been linked to human diseases, including retinopathies and ocular defects. Here, we focus on TMEM107, a protein localized to the transition zone of primary cilia. TMEM107 mutations were found in patients with Joubert and Meckel-Gruber syndromes. A mouse model lacking Tmem107 exhibited eye defects such as anophthalmia and microphthalmia, affecting retina differentiation. Tmem107 expression during prenatal mouse development correlated with phenotype occurrence, with enhanced expression in differentiating retina and optic stalk. TMEM107 deficiency in retinal organoids resulted in the loss of primary cilia, down-regulation of retina-specific genes, and cyst formation. Knocking out TMEM107 in human ARPE-19 cells prevented primary cilia formation and impaired response to Smoothened agonist treatment because of ectopic activation of the SHH pathway. Our data suggest TMEM107 plays a crucial role in early vertebrate eye development and ciliogenesis in the differentiating retina.

MicroRNAs are necessary for the emergence of Purkinje cell identity

Brain computations are dictated by the unique morphology and connectivity of neuronal subtypes, features established by closely timed developmental events. MicroRNAs (miRNAs) are critical for brain development, but current technologies lack the spatiotemporal resolution to determine how miRNAs instruct the steps leading to subtype identity. Here, we developed new tools to tackle this major gap. Fast and reversible miRNA loss-of-function revealed that miRNAs are necessary for cerebellar Purkinje cell (PC) differentiation, which previously appeared miRNA-independent, and resolved distinct miRNA critical windows in PC dendritogenesis and climbing fiber synaptogenesis, key determinants of PC identity. To identify underlying mechanisms, we generated a mouse model, which enables precise mapping of miRNAs and their targets in rare cell types. With PC-specific maps, we found that the PC-enriched miR-206 drives exuberant dendritogenesis and modulates synaptogenesis. Our results showcase vastly improved approaches for dissecting miRNA function and reveal that many critical miRNA mechanisms remain largely unexplored.

Highlights

Fast miRNA loss-of-function with T6B impairs postnatal Purkinje cell developmentReversible T6B reveals critical miRNA windows for dendritogenesis and synaptogenesisConditional Spy3-Ago2 mouse line enables miRNA-target network mapping in rare cellsPurkinje cell-enriched miR-206 regulates its unique dendritic and synaptic morphology.

Role of microRNAs and their downstream target transcription factors in zebrafish thrombopoiesis

Previous studies have shown that human platelets and megakaryocytes carry microRNAs suggesting their role in platelet function and megakaryocyte development, respectively. However, a comprehensive study on the microRNAs and their targets has not been undertaken. Zebrafish thrombocytes could be used as a model to study their role in megakaryocyte maturation and platelet function because thrombocytes have both megakaryocyte features and platelet properties. In our laboratory, we identified 15 microRNAs in thrombocytes using single-cell RNA sequencing. We knocked down each of these 15 microRNAs by the piggyback method and found knockdown of three microRNAs, mir-7148, let-7b, and mir-223 in adult zebrafish led to an increase in the percentage of thrombocytes. Functional thrombocyte analysis using plate tilt assay showed no modulatory effect of the three microRNAs on thrombocyte aggregation/agglutination. We also found enhanced thrombosis using arterial laser thrombosis assay in a group of zebrafish larvae after mir-7148, let-7b, and mir-223 knockdowns. These results suggested mir-7148, let-7b, and mir-223 are repressors for thrombocyte production. We then explored miRWalk database for let-7b downstream targets and then selected those that are expressed in thrombocytes, and from this list based on their role in differentiation selected 14 genes, rorca, tgif1, rfx1a, deaf1, zbtb18, mafba, cebpa, spi1a, spi1b, fhl3b, ikzf1, irf5, irf8, and lbx1b that encode transcriptional regulators. The qRT-PCR analysis of expression levels of the above genes following let-7b knockdown showed changes in the expression of 13 targets. We then studied the effect of the 13 targets on thrombocyte production and identified 5 genes, irf5, tgif1, irf8, cebpa, and rorca that showed thrombocytosis and one gene, ikzf1 that showed thrombocytopenia. Furthermore, we tested whether mir-223 regulates any of the above 13 transcription factors after mir-223 knockdown using qRT-PCR. Six of the 13 genes showed similar gene expression as observed with let-7b knockdown and 7 genes showed opposing results. Thus, our results suggested a possible regulatory network in common with both let-7b and mir-223. We also identified that tgif1, cebpa, ikzf1, irf5, irf8, and ikzf1 play a role in thrombopoiesis. Since the ikzf1 gene showed a differential expression profile in let-7b and mir-223 knockdowns but resulted in thrombocytopenia in ikzf1 knockdown in both adults and larvae we also studied an ikzf1 mutant and showed the mutant had thrombocytopenia. Taken together, these studies showed that thrombopoiesis is controlled by a network of transcription regulators that are regulated by multiple microRNAs in both positive and negative manner resulting in overall inhibition of thrombopoiesis.

Integrated omics and machine learning-assisted profiling of cysteine-rich-receptor-like kinases from three peanut spp. revealed their role in multiple stresses

Arachis hypogaea (peanut) is a leading oil and protein-providing crop with a major food source in many countries. It is mostly grown in tropical regions and is largely affected by abiotic and biotic stresses. Cysteine-rich receptor-like kinases (CRKs) is a family of transmembrane proteins that play important roles in regulating stress-signaling and defense mechanisms, enabling plants to tolerate stress conditions. However, almost no information is available regarding this gene family in Arachis hypogaea and its progenitors. This study conducts a pangenome-wide investigation of A. hypogaea and its two progenitors, A. duranensis and A. ipaensis CRK genes (AhCRKs, AdCRKs, and AiCRKs). The gene structure, conserved motif patterns, phylogenetic history, chromosomal distribution, and duplication were studied in detail, showing the intraspecies structural conservation and evolutionary patterns. Promoter cis-elements, protein-protein interactions, GO enrichment, and miRNA targets were also predicted, showing their potential functional conservation. Their expression in salt and drought stresses was also comprehensively studied. The CRKs identified were divided into three groups, phylogenetically. The expansion of this gene family in peanuts was caused by both types of duplication: tandem and segmental. Furthermore, positive as well as negative selection pressure directed the duplication process. The peanut CRK genes were also enriched in hormones, light, development, and stress-related elements. MicroRNA (miRNA) also targeted the AhCRK genes, which suggests the regulatory association of miRNAs in the expression of these genes. Transcriptome datasets showed that AhCRKs have varying expression levels under different abiotic stress conditions. Furthermore, the multi-stress responsiveness of the AhCRK genes was evaluated using a machine learning-based method, Random Forest (RF) classifier. The 3D structures of AhCRKs were also predicted. Our study can be utilized in developing a detailed understanding of the stress regulatory mechanisms of the CRK gene family in peanuts and its further studies to improve the genetic makeup of peanuts to thrive better under stress conditions.

Targeted Expression to Liver of an antimiR-33 Sponge as a Gene Therapy Strategy against Hypercholesterolemia: In Vitro Study

Atherosclerosis is the leading cause of cardiovascular diseases in Mexico and worldwide. The membrane transporters ABCA1 and ABCG1 are involved in the reverse transport of cholesterol and stimulate the HDL synthesis in hepatocytes, therefore the deficiency of these transporters promotes the acceleration of atherosclerosis. MicroRNA-33 (miR-33) plays an important role in lipid metabolism and exerts a negative regulation on the transporters ABCA1 and ABCG1. It is known that by inhibiting the function of miR-33 with antisense RNA, HDL levels increase and atherogenic risk decreases. Therefore, in this work, a genetic construct, pPEPCK-antimiR-33-IRES2-EGFP, containing a specific antimiR-33 sponge with two binding sites for miR-33 governed under the PEPCK promoter was designed, constructed, and characterized, the identity of which was confirmed by enzymatic restriction, PCR, and sequencing. Hep G2 and Hek 293 FT cell lines, as well as a mouse hepatocyte primary cell culture were transfected with this plasmid construction showing expression specificity of the PEPCK promoter in hepatic cells. An analysis of the relative expression of miR-33 target messengers showed that the antimiR-33 sponge indirectly induces the expression of its target messengers (ABCA1 and ABCG1). This strategy could open new specific therapeutic options for hypercholesterolemia and atherosclerosis, by blocking the miR-33 specifically in hepatocytes.

An evaluation of the effects of mixed heavy metals on prediabetes and type 2 diabetes: epidemiological and toxicogenomic analysis

The link between mixed heavy metals (mercury, lead, and cadmium), prediabetes, and type 2 diabetes mellitus (T2DM), especially molecular mechanisms, is poorly understood. Thus, we aimed to identify the association between mixed heavy metals and T2DM and its components using a data set from the Korean National Health and Nutrition Examination Survey. We further analyzed the main molecular mechanisms implicated in T2DM development induced by mixed heavy metals using in-silico analysis. Our findings observed that serum mercury was associated with prediabetes, elevated glucose, and ln2-transformed glucose when using different statistical methods. "AGE-RAGE signaling pathway in diabetic complications", "non-alcoholic fatty liver disease", "metabolic Syndrome X", and three miRNAs (hsa-miR-98-5p, hsa-let-7a-5p, and hsa-miR-34a-5p) were listed as the most important molecular mechanisms related to T2DM development caused by mixed heavy metals. These miRNA sponge structures were created and examined, and they may be beneficial in the treatment of T2DM. The predicted cutoff values for three heavy metal levels linked to T2DM and its components were specifically identified. Our results imply that chronic exposure to heavy metals, particularly mercury, may contribute to the development of T2DM. To understand the changes in the pathophysiology of T2DM brought on by a combination of heavy metals, more research is required.

Basic Principles of RNA Interference: Nucleic Acid Types and In Vitro Intracellular Delivery Methods

Since its discovery in 1989, RNA interference (RNAi) has become a widely used tool for the in vitro downregulation of specific gene expression in molecular biological research. This basically involves a complementary RNA that binds a target sequence to affect its transcription or translation process. Currently, various small RNAs, such as small interfering RNA (siRNA), micro RNA (miRNA), small hairpin RNA (shRNA), and PIWI interacting RNA (piRNA), are available for application on in vitro cell culture, to regulate the cells' gene expression by mimicking the endogenous RNAi-machinery. In addition, several biochemical, physical, and viral methods have been established to deliver these RNAs into the cell or nucleus. Since each RNA and each delivery method entail different off-target effects, limitations, and compatibilities, it is crucial to understand their basic mode of action. This review is intended to provide an overview of different nucleic acids and delivery methods for planning, interpreting, and troubleshooting of RNAi experiments.

In-silico engineering of RNA nanoplatforms to promote the diabetic wound healing

One of the most notable required features of wound healing is the enhancement of angiogenesis, which aids in the acceleration of regeneration. Poor angiogenesis during diabetic wound healing is linked to a shortage of pro-angiogenic or an increase in anti-angiogenic factors. As a result, a potential treatment method is to increase angiogenesis promoters and decrease suppressors. Incorporating microRNAs (miRNAs) and small interfering RNAs (siRNAs), two forms of quite small RNA molecules, is one way to make use of RNA interference. Several different types of antagomirs and siRNAs are now in the works to counteract the negative effects of miRNAs. The purpose of this research is to locate novel antagonists for miRNAs and siRNAs that target multiple genes to promote angiogenesis and wound healing in diabetic ulcers.In this context, we used gene ontology analysis by exploring across several datasets. Following data analysis, it was processed using a systems biology approach. The feasibility of incorporating the proposed siRNAs and miRNA antagomirs into polymeric bioresponsive nanocarriers for wound delivery was further investigated by means of a molecular dynamics (MD) simulation study. Among the three nanocarriers tested (Poly (lactic-co-glycolic acid) (PLGA), Polyethylenimine (PEI), and Chitosan (CTS), MD simulations show that the integration of PLGA/hsa-mir-422a is the most stable (total energy = -1202.62 KJ/mol, Gyration radius = 2.154 nm, and solvent-accessible surface area = 408.416 nm2). With values of -25.437 KJ/mol, 0.047 nm for the Gyration radius, and 204.563 nm2 for the SASA, the integration of the second siRNA/ Chitosan took the last place. The results of the systems biology and MD simulations show that the suggested RNA may be delivered through bioresponsive nanocarriers to speed up wound healing by boosting angiogenesis.

Notch directs telencephalic development and controls neocortical neuron fate determination by regulating microRNA levels

The central nervous system contains a myriad of different cell types produced from multipotent neural progenitors. Neural progenitors acquire distinct cell identities depending on their spatial position, but they are also influenced by temporal cues to give rise to different cell populations over time. For instance, the progenitors of the cerebral neocortex generate different populations of excitatory projection neurons following a well-known sequence. The Notch signaling pathway plays crucial roles during this process, but the molecular mechanisms by which Notch impacts progenitor fate decisions have not been fully resolved. Here, we show that Notch signaling is essential for neocortical and hippocampal morphogenesis, and for the development of the corpus callosum and choroid plexus. Our data also indicate that, in the neocortex, Notch controls projection neuron fate determination through the regulation of two microRNA clusters that include let-7, miR-99a/100 and miR-125b. Our findings collectively suggest that balanced Notch signaling is crucial for telencephalic development and that the interplay between Notch and miRNAs is essential for the control of neocortical progenitor behaviors and neuron cell fate decisions.

Clinical Significance of microRNAs in Hematologic Malignancies and Hematopoietic Stem Cell Transplantation

Hematologic malignancies are a group of neoplastic conditions that can develop from any stage of the hematopoiesis cascade. Small non-coding microRNAs (miRNAs) play a crucial role in the post-transcriptional regulation of gene expression. Mounting evidence highlights the role of miRNAs in malignant hematopoiesis via the regulation of oncogenes and tumor suppressors involved in proliferation, differentiation, and cell death. In this review, we provide current knowledge about dysregulated miRNA expression in the pathogenesis of hematological malignancies. We summarize data about the clinical utility of aberrant miRNA expression profiles in hematologic cancer patients and their associations with diagnosis, prognosis, and the monitoring of treatment response. Moreover, we will discuss the emerging role of miRNAs in hematopoietic stem cell transplantation (HSCT), and severe post-HSCT complications, such as graft-versus-host disease (GvHD). The therapeutical potential of the miRNA-based approach in hemato-oncology will be outlined, including studies with specific antagomiRs, mimetics, and circular RNAs (circRNAs). Since hematologic malignancies represent a full spectrum of disorders with different treatment paradigms and prognoses, the potential use of miRNAs as novel diagnostic and prognostic biomarkers might lead to improvements, resulting in a more accurate diagnosis and better patient outcomes.

In silico identification of molecular mechanisms for stroke risk caused by heavy metals and their mixtures: sponges and drugs involved

This study used various approaches and databases to evaluate the molecular processes and identify miRNA sponges and drugs associated with the development of stroke caused by heavy metals and their combinations. We found that the genes ALB (albumin), IL1B (Interleukin-1β), F2 (coagulation factor II), APOA1 (apolipoprotein A1), IL6 (Interleukin 6), and NOS2 (nitric oxide synthase 2) were linked to the development of strokes by 18 chemicals and a combination of cadmium, copper, and lead. These results may point to the significance of detoxification and neuroinflammation in stroke as well as the potential for targeting these genes in future stroke therapies. ALB and IL1B were the most common and significant genes. The "selenium micronutrient network," "vitamin B12 metabolism," and "folate metabolism" were shown to be the most significant pathways connected to the risk of stroke brought on by combined heavy metals. The two main cellular elements that may increase the risk of stroke caused by heavy metals were discovered to be "blood microparticle" and "endoplasmic reticulum lumen." We also observed an important chromosome (chr7p15.3), two transcription factors (NFKB2 [nuclear factor kappa B subunit 2] and NR1I2 [nuclear receptor subfamily 1 group, member 2]), and four microRNAs (hsa-miR-26a-5p, hsa-miR-9-5p, hsa-miR-124-3p, and hsa-miR-155-5p) associated with stroke caused by combined heavy metals. Additionally, for these miRNAs, we created and examined in silico microRNA sponge sequences. Triflusal and andrographolide have been identified as potential treatments for heavy metal-induced stroke. Taken together, heavy metals may be a significant contributor to the pathophysiology of stroke, but further investigation into the precise molecular pathways implicated in stroke pathophysiology is required to corroborate these findings.

Role of MicroRNAs and their Downstream Target Transcription Factors in Zebrafish Thrombopoiesis

Previous studies have shown that human platelets and megakaryocytes carry microRNAs suggesting their role in platelet function and megakaryocyte development, respectively. However, a comprehensive study on the microRNAs and their targets has not been undertaken. Zebrafish thrombocytes could be used as a model to study their role in megakaryocyte maturation and platelet function because thrombocytes have both megakaryocyte features and platelet properties. In our laboratory, we identified 15 microRNAs in thrombocytes using single-cell RNA sequencing. We knocked down each of these 15 microRNAs by the piggyback method and found knockdown of three microRNAs, mir-7148, let-7b , and mir-223 in adult zebrafish led to an increase in the percentage of thrombocytes. Functional thrombocyte analysis using plate tilt assay showed no modulatory effect of the three microRNAs on thrombocyte aggregation/agglutination. We also found enhanced thrombosis using arterial laser thrombosis assay in a group of zebrafish larvae after mir-7148, let-7b , and mir-223 knockdowns. These results suggested mir-7148, let-7b , and mir-223 are repressors for thrombocyte production. We then explored miRWalk database for let-7b downstream targets and then selected those that are expressed in thrombocytes, and from this list based on their role in differentiation selected 14 genes, rorca, tgif1, rfx1a, deaf1, zbtb18, mafba, cebpa, spi1a, spi1b, fhl3b, ikzf1, irf5, irf8 , and lbx1b that encode transcriptional regulators. The qRT-PCR analysis of expression levels of the above genes following let-7b knockdown showed changes in the expression of 13 targets. We then studied the effect of the 13 targets on thrombocyte production and identified 5 genes, irf5, tgif1, irf8, cebpa , and rorca that showed thrombocytosis and one gene, ikzf1 that showed thrombocytopenia. Furthermore, we tested whether mir-223 regulates any of the above 13 transcription factors after mir-223 knockdown using qRT-PCR. Six of the 13 genes showed similar gene expression as observed with let-7b knockdown and 7 genes showed opposing results. Thus, our results suggested a possible regulatory network in common with both let-7b and mir-223 . We also identified that tgif1, cebpa, ikzf1, irf5 , irf8 , and ikzf1 play a role in thrombopoiesis. Since the ikzf1 gene showed a differential expression profile in let-7b and mir-223 knockdowns but resulted in thrombocytopenia in ikzf1 knockdown in both adults and larvae we also studied an ikzf1 mutant and showed the mutant had thrombocytopenia. Taken together, these studies showed that thrombopoiesis is controlled by a network of transcription regulators that are regulated by multiple microRNAs in both positive and negative manner resulting in overall inhibition of thrombopoiesis.

Skeletal diseases caused by mutations in PTH1R show aberrant differentiation of skeletal progenitors due to dysregulation of DEPTOR

Alterations in the balance between skeletogenesis and adipogenesis is a pathogenic feature in multiple skeletal disorders. Clinically, enhanced bone marrow adiposity in bones impairs mobility and increases fracture risk, reducing the quality of life of patients. The molecular mechanism that underlies the balance between skeletogenesis and adipogenesis is not completely understood but alterations in skeletal progenitor cells' differentiation pathway plays a key role. We recently demonstrated that parathyroid hormone (PTH)/PTH-related peptide (PTHrP) control the levels of DEPTOR, an inhibitor of the mechanistic target of rapamycin (mTOR), and that DEPTOR levels are altered in different skeletal diseases. Here, we show that mutations in the PTH receptor-1 (PTH1R) alter the differentiation of skeletal progenitors in two different skeletal genetic disorders and lead to accumulation of fat or cartilage in bones. Mechanistically, DEPTOR controls the subcellular localization of TAZ (transcriptional co-activator with a PDZ-binding domain), a transcriptional regulator that governs skeletal stem cells differentiation into either bone and fat. We show that DEPTOR regulation of TAZ localization is achieved through the control of Dishevelled2 (DVL2) phosphorylation. Depending on nutrient availability, DEPTOR directly interacts with PTH1R to regulate PTH/PTHrP signaling or it forms a complex with TAZ, to prevent its translocation to the nucleus and therefore inhibit its transcriptional activity. Our data point DEPTOR as a key molecule in skeletal progenitor differentiation; its dysregulation under pathologic conditions results in aberrant bone/fat balance.

Interactions between heavy metals and sleep duration among pre-and postmenopausal women: A current approach to molecular mechanisms involved

The effects of heavy metals (cadmium, lead, and mercury) and their mixtures on sleep duration in pre-and postmenopausal women, particularly the molecular mechanisms, remain unknown. Here, we assessed the interaction between heavy metals and sleep duration among pre-and postmenopausal women (n = 1134). Furthermore, molecular mechanisms related to sleep disorders induced by studied heavy metals were further analyzed to support the previous findings. We found that serum lead levels were positively related to weekend and weekday sleep duration in premenopausal women. There were interactions between serum lead and mercury and menopausal status for sleep duration. Serum lead and mercury levels were shown to be inversely related to sleep duration in postmenopausal women. Despite the lack of statistically significant associations between mixed heavy metals and sleep duration, there were increasing trends in premenopausal women's sleeping patterns and decreasing trends in postmenopausal women's sleeping patterns. In silico analysis, IL1B, hsa-21-5p, hsa-887-3p, hsa-877-3p, and NR4A1 were identified as the most relevant genes, miRNAs, and transcription factors linked with sleep disorders induced by combined heavy metals (cadmium, lead, and mercury). Furthermore, "type 1 melanocortin receptor binding," "endocrine hormone secretion," "interleukin-1 receptor antagonist activity," "altered melanocortin system," and "sleep wake disorders" were identified as the predominant molecular mechanisms involved in the pathophysiology of sleep disorders induced by the studied heavy metals. Cut off point values and miRNA sponge templates for heavy metal exposure levels relevant to sleep disorders in pre- and postmenopausal women were reported. Future research is needed to verify our findings and provide insight into the molecular processes of long-term mixed heavy metal exposure in various populations, such as children and the elderly.

miRNA as Drug: Antagomir and Beyond

MicroRNA (miRNA) are small, single-stranded, non-coding RNA molecules containing 20 to 25 nucleotides, present in all body fluids; they can be used as biomarkers, but much more than this as a therapy to replace missing protein or to downregulate excess or aberrant synthesis; here we report possible insight to future studies, needed in this exciting field.

Role of MicroRNAs, Aptamers in Neuroinflammation and Neurodegenerative Disorders

Exploring the microRNAs and aptamers for their therapeutic role as biological drugs has expanded the horizon of its applicability against various human diseases, explicitly targeting the genetic materials. RNA-based therapeutics are widely being explored for the treatment and diagnosis of multiple diseases, including neurodegenerative disorders (NDD). Latter includes microRNA, aptamers, ribozymes, and small interfering RNAs (siRNAs), which control the gene expression mainly at the transcriptional strata. One RNA transcript translates into different protein types; hence, therapies targeted at the transcriptional sphere may have prominent and more extensive effects than alternative therapeutics. Unlike conventional gene therapy, RNAs, upon delivery, can either altogether abolish or alter the synthesis of the protein of interest, therefore, regulating their activities in a controlled and diverse manner. NDDs like Alzheimer's disease, Parkinson's disease, Huntington's disease, multiple sclerosis, Prion disease, and others are characterized by deposition of misfolded protein such as amyloid-ß, tau, α-synuclein, huntingtin and prion proteins. Neuroinflammation, one of the perquisites for neurodegeneration, is induced during neurodegenerative pathogenesis. In this review, we discuss microRNAs and aptamers' role as two different RNA-based approaches for their unique ability to regulate protein production at the transcription level, hence offering many advantages over other biologicals. The microRNA acts either by alleviating the malfunctioning RNA expression or by working as a replacement to lost microRNA. On the contrary, aptamer act as a chemical antibody and forms an aptamer-target complex.

Cadmium, lead, and mercury mixtures interact with non-alcoholic fatty liver diseases

There is a scarcity of studies on the interactions between heavy metals and non-alcoholic fatty liver disease (NAFLD). Using a variety of statistical approaches, we investigated the impact of three common heavy metals on liver enzymes and NAFLD markers in a Korean adult population. We observed that cadmium, mercury, and lead all demonstrated positive correlations with liver enzymes and NAFLD indices. Our findings were mostly robust in secondary analysis, which included three novel mixture modeling approaches (WQS, qgcomp, and BKMR) as well as in silico investigation of molecular mechanisms (genes, miRNAs, biological processes, pathways, and illnesses). The 16 genes interacted with a mixture of heavy metals, which was linked to the development of NAFLD. Co-expression was discovered in nearly half of the interactions between the 18 NAFLD-linked genes. Key molecular pathways implicated in the pathogenesis of NAFLD generated by the heavy metal combination include activated oxidative stress, altered lipid metabolism, and increased cytokines and inflammatory response. Heavy metal exposure levels were related to liver enzymes and NAFLD indices, and cutoff criteria were revealed. More studies are needed to validate our findings and gain knowledge about the effects of chronic combined heavy metal exposure on adult and child liver function and the likelihood of developing NAFLD. To reduce the occurrence of NAFLD, early preventative and regulatory actions (half-yearly screening of workers at high-risk facilities; water filtration; avoiding excessive amounts of seafood, etc.) should be taken.

Modular scaffolding by lncRNA HOXA10-AS promotes oral cancer progression

Recent findings have implicated long noncoding RNAs (lncRNAs) as pivotal gene regulators for diverse biological processes, despite their lack of protein-coding capabilities. Accumulating evidence suggests the significance of lncRNAs in mediating cell signaling pathways, especially those associated with tumorigenesis. Consequently, lncRNAs have emerged as novel functional regulators and indicators of cancer development and malignancy. Recent transcriptomic profiling has recognized a tumor-biased expressed lncRNA, the HOXA10-AS transcript, whose expression is associated with patient survival. Functional cell-based assays show that the HOXA10-AS transcript is essential in the regulation of oral cancer growth and metastasis. LncRNA expression is also associated with drug sensitivity. In this study, we identify that HOXA10-AS serves as a modular scaffold for TP63 mRNA processing and that such involvement regulates cancer growth. These findings provide a functional interpretation of lncRNA-mediated molecular regulation, highlighting the significance of the lncRNA transcriptome in cancer biology.

The Involvement of microRNAs in Plant Lignan Biosynthesis—Current View

Lignans, as secondary metabolites synthesized within a phenylpropanoid pathway, play various roles in plants, including their involvement in growth and plant defense processes. The health and nutritional benefits of lignans are unquestionable, and many studies have been devoted to these attributes. Although the regulatory role of miRNAs in the biosynthesis of secondary metabolites has been widely reported, there is no systematic review available on the miRNA-based regulatory mechanism of lignans biosynthesis. However, the genetic background of lignan biosynthesis in plants is well characterized. We attempted to put together a regulatory mosaic based on current knowledge describing miRNA-mediated regulation of genes, enzymes, or transcription factors involved in this biosynthesis process. At the same time, we would like to underline the fact that further research is necessary to improve our understanding of the miRNAs regulating plant lignan biosynthesis by exploitation of current approaches for functional identification of miRNAs.

Recent trends in miRNA therapeutics and the application of plant miRNA for prevention and treatment of human diseases

Background

Researchers now have a new avenue to investigate when it comes to miRNA-based therapeutics. miRNAs have the potential to be valuable biomarkers for disease detection. Variations in miRNA levels may be able to predict changes in normal physiological processes. At the epigenetic level, miRNA has been identified as a promising candidate for distinguishing and treating various diseases and defects.

Main body

In recent pharmacology, plants miRNA-based drugs have demonstrated a potential role in drug therapeutics. The purpose of this review paper is to discuss miRNA-based therapeutics, the role of miRNA in pharmacoepigenetics modulations, plant miRNA inter-kingdom regulation, and the therapeutic value and application of plant miRNA for cross-kingdom approaches. Target prediction and complementarity with host genes, as well as cross-kingdom gene interactions with plant miRNAs, are also revealed by bioinformatics research. We also show how plant miRNA can be transmitted from one species to another by crossing kingdom boundaries in this review. Despite several unidentified barriers to plant miRNA cross-transfer, plant miRNA-based gene regulation in trans-kingdom gene regulation may soon be valued as a possible approach in plant-based drug therapeutics.

Conclusion

This review summarised the biochemical synthesis of miRNAs, pharmacoepigenetics, drug therapeutics and miRNA transkingdom transfer.

MicroRNA Targeting

MicroRNAs (miRNAs) are small noncoding elements that play essential roles in the posttranscriptional regulation of biochemical processes. miRNAs recognize and target multiple mRNAs; therefore, investigating miRNA dysregulation is an indispensable strategy to understand pathological conditions and to design innovative drugs. Targeting miRNAs in diseases improve outcomes of several therapeutic strategies thus, this present study highlights miRNA targeting methods through experimental assays and bioinformatics tools. The first part of this review focuses on experimental miRNA targeting approaches for elucidating key biochemical pathways. A growing body of evidence about the miRNA world reveals the fact that it is not possible to uncover these molecules' structural and functional characteristics related to the biological processes with a deterministic approach. Instead, a systemic point of view is needed to truly understand the facts behind the natural complexity of interactions and regulations that miRNA regulations present. This task heavily depends both on computational and experimental capabilities. Fortunately, several miRNA bioinformatics tools catering to nonexperts are available as complementary wet-lab approaches. For this purpose, this work provides recent research and information about computational tools for miRNA targeting research.

MicroRNA Databases and Tools

In this era of big data, sets of methodologies and strategies are designed to extract knowledge from huge volumes of data. However, the cost of where and how to get this information accurately and quickly is extremely important, given the diversity of genomes and the different ways of representing that information. Among the huge set of information and relationships that the genome carries, there are sequences called miRNAs (microRNAs). These sequences were described in the 1990s and are mainly involved in mechanisms of regulation and gene expression. Having this in mind, this chapter focuses on exploring the available literature and providing useful and practical guidance on the miRNA database and tools topic. For that, we organized and present this text in two ways: (a) the update reviews and articles, which best summarize and discuss the theme; and (b) our update investigation on miRNA literature and portals about databases and tools. Finally, we present the main challenge and a possible solution to improve resources and tools.

Classical and noncanonical functions of miRNAs in cancers

Alterations in microRNAs (miRNAs) expression are causative in the initiation and progression of human cancers. The molecular events responsible for the widespread differential expression of miRNAs in malignancy are exemplified by their location in cancer-associated genomic regions, epigenetic mechanisms, transcriptional dysregulation, chemical modifications and editing, and alterations in miRNA biogenesis proteins. The classical miRNA function is synonymous with post-transcriptional repression of target protein genes. However, several studies have reported miRNAs functioning outside this paradigm and some of these novel modes of regulation of gene expression have been implicated in cancers. Here, we summarize key aspects of miRNA involvement in cancer, with a special focus on these lesser-studied mechanisms of action.

RNF43 inhibits WNT5A-driven signaling and suppresses melanoma invasion and resistance to the targeted therapy

RNF43 is an E3 ubiquitin ligase and known negative regulator of WNT/β-catenin signaling. We demonstrate that RNF43 is also a regulator of noncanonical WNT5A-induced signaling in human cells. Analysis of the RNF43 interactome using BioID and immunoprecipitation showed that RNF43 can interact with the core receptor complex components dedicated to the noncanonical Wnt pathway such as ROR1, ROR2, VANGL1, and VANGL2. RNF43 triggers VANGL2 ubiquitination and proteasomal degradation and clathrin-dependent internalization of ROR1 receptor and inhibits ROR2 activation. These activities of RNF43 are physiologically relevant and block pro-metastatic WNT5A signaling in melanoma. RNF43 inhibits responses to WNT5A, which results in the suppression of invasive properties of melanoma cells. Furthermore, RNF43 prevented WNT5A-assisted development of resistance to BRAF V600E and MEK inhibitors. Next, RNF43 acted as melanoma suppressor and improved response to targeted therapies in vivo. In line with these findings, RNF43 expression decreases during melanoma progression and RNF43-low patients have a worse prognosis. We conclude that RNF43 is a newly discovered negative regulator of WNT5A-mediated biological responses that desensitizes cells to WNT5A.

Inhibition of miR-222 by Oncolytic Adenovirus-Encoded miRNA Sponges Promotes Viral Oncolysis and Elicits Antitumor Effects in Pancreatic Cancer Models

Oncolytic adenoviruses (OA) are envisioned as a therapeutic option for patients with cancer, designed to preferentially replicate in cancer cells. However, the high number of genetic alterations in tumors can generate a context in which adenoviruses have difficulties replicating. Abnormal miRNAs expression is a trademark of pancreatic cancer, with several oncogenic miRNAs playing essential roles in cancer-associated pathways. The perturbed miRNome induces reprogramming of gene expression in host cells that can impact the complex interplay between cellular processes and viral replication. We have studied the effects of overexpressed miRNAs on oncolytic adenoviral activity and identified miRNAs modulators of adenoviral oncolysis in pancreatic cancer cells. Inhibition of the highly upregulated miR-222 sensitized cancer cells to oncolysis. To provide a therapeutic application to this insight, we engineered the oncolytic adenovirus AdNuPARmE1A with miR-222 binding sites, working as sponges to withdraw the miRNA from the cellular environment. AdNuPAR-E-miR222-S mediated-decrease of miR-222 expression in pancreatic cancer cells strongly improved the viral yield and enhanced the adenoviral cytotoxic effects. Antitumoral studies confirmed a high activity for AdNuPARmE1A-miR222-S in vivo, controlling tumor progression more effectively than the scrambled control virus in xenografts. We demonstrated that the increased antitumor potency of the novel oncolytic virus resulted from the combinatory effects of miR-222 oncomiR inhibition and the restoration of miR-222 target genes activity enhancing viral fitness.

MIR448 antagomir reduces arrhythmic risk after myocardial infarction by upregulating the cardiac sodium channel

Cardiac ischemia is associated with arrhythmias; however, effective therapies are currently limited. The cardiac voltage-gated sodium channel α subunit (SCN5A), encoding the Na_v1.5 current, plays a key role in the cardiac electrical conduction and arrhythmic risk. Here, we show that hypoxia reduces Na_v1.5 through effects on a miR, miR-448. miR-448 expression is increased in ischemic cardiomyopathy. miR-448 has a conserved binding site in 3′-UTR of SCN5A. miR-448 binding to this site suppressed SCN5A expression and sodium currents. Hypoxia-induced HIF-1α and NF-κB were major transcriptional regulators for MIR448. Moreover, hypoxia relieved MIR448 transcriptional suppression by RE1 silencing transcription factor. Therefore, miR-448 inhibition reduced arrhythmic risk after myocardial infarction. Here, we show that ischemia drove miR-448 expression, reduced Na_v1.5 current, and increased arrhythmic risk. Arrhythmic risk was improved by preventing Na_v1.5 downregulation, suggesting a new approach to antiarrhythmic therapy.

Ischemic induction of miR-448 negatively regulates the cardiac sodium channel Nav1.5, and inhibiting miR-448 raises Nav1.5 and reduces arrhythmic risk after myocardial infarction in mice.

Mutations in GRK2 cause Jeune syndrome by impairing Hedgehog and canonical Wnt signaling

Mutations in genes affecting primary cilia cause ciliopathies, a diverse group of disorders often affecting skeletal development. This includes Jeune syndrome or asphyxiating thoracic dystrophy (ATD), an autosomal recessive skeletal disorder. Unraveling the responsible molecular pathology helps illuminate mechanisms responsible for functional primary cilia. We identified two families with ATD caused by loss-of-function mutations in the gene encoding adrenergic receptor kinase 1 (ADRBK1 or GRK2). GRK2 cells from an affected individual homozygous for the p.R158* mutation resulted in loss of GRK2, and disrupted chondrocyte growth and differentiation in the cartilage growth plate. GRK2 null cells displayed normal cilia morphology, yet loss of GRK2 compromised cilia-based signaling of Hedgehog (Hh) pathway. Canonical Wnt signaling was also impaired, manifested as a failure to respond to Wnt ligand due to impaired phosphorylation of the Wnt co-receptor LRP6. We have identified GRK2 as an essential regulator of skeletogenesis and demonstrate how both Hh and Wnt signaling mechanistically contribute to skeletal ciliopathies.

The Role of MicroRNAs in Acute Respiratory Distress Syndrome and Sepsis, From Targets to Therapies: A Narrative Review

Acute respiratory distress syndrome (ARDS) is a significant cause of morbidity and mortality in the intensive care unit (ICU) and is characterized by lung epithelial and endothelial cell injury, with increased permeability of the alveolar-capillary membrane, leading to pulmonary edema, severe hypoxia, and difficulty with ventilation. The most common cause of ARDS is sepsis, and currently, treatment of ARDS and sepsis has consisted mostly of supportive care because targeted therapies have largely been unsuccessful. The molecular mechanisms behind ARDS remain elusive. Recently, a number of microRNAs (miRNAs) identified through high-throughput screening studies in ARDS patients and preclinical animal models have suggested a role for miRNA in the pathophysiology of ARDS. miRNAs are small noncoding RNAs ranging from 18 to 24 nucleotides that regulate gene expression via inhibition of the target mRNA translation or by targeting complementary mRNA for early degradation. Unsurprisingly, some miRNAs that are differentially expressed in ARDS overlap with those important in sepsis. In addition, circulatory miRNA may be useful as biomarkers or as targets for pharmacologic therapy. This can be revolutionary in a syndrome that has neither a measurable indicator of the disease nor a targeted therapy. While there are currently no miRNA-based therapies targeted for ARDS, therapies targeting miRNA have reached phase II clinical trials for the treatment of a wide range of diseases. Further studies may yield a unique miRNA profile pattern that serves as a biomarker or as targets for miRNA-based pharmacologic therapy. In this review, we discuss miRNAs that have been found to play a role in ARDS and sepsis, the potential mechanism of how particular miRNAs may contribute to the pathophysiology of ARDS, and strategies for pharmacologically targeting miRNA as therapy.

miR-183/96/182 cluster is an important morphogenetic factor targeting PAX6 expression in differentiating human retinal organoids

MicroRNAs (miRNAs), a class of small, noncoding RNA molecules represent important regulators of gene expression. Recent reports have implicated their role in the cell specification process acting as "fine-tuners" to ensure the precise gene expression at the specific stage of cell differentiation. Here, we used retinal organoids differentiated from human pluripotent stem cells (hPSCs) as a model to closely investigate the role of a sensory organ-specific and evolutionary conserved miR-183/96/182 cluster. Using a miRNA tough decoy approach, we inhibited the miR-183/96/182 cluster in hPSCs. Inhibition of the miRNA cluster resulted in an increased expansion of neuroepithelium leading to abnormal "bulged" neural retina in organoids, associated with upregulation of neural-specific and retinal-specific genes. Importantly, we identified PAX6, a well-known essential gene in neuroectoderm specification, as a target of the miR-183/96/182 cluster members. Taken together, the miR-183/96/182 cluster not only represents an important regulator of PAX6 expression, but it also plays a crucial role in retinal tissue morphogenesis.

Exploring the potential microRNA sponge interactions of breast cancer based on some known interactions

MicroRNA (miRNA) sponges' regulatory mechanisms play an important role in developing human cancer. Herein, we develop a new method to explore potential miRNA sponge interactions (EPMSIs) for breast cancer. Based on some known interactions, and a matching gene expression profile, EPMSIs explored other potential miRNA sponge interactions for breast cancer. Every interaction is inferred with a value representing interaction intensity. Then, we apply a clustering algorithm called BCPlaid to potential interactions. Ten modules are identified; nine of them are closely associated with biological enrichments. When we employ a classification algorithm to separate normal and tumor samples in each module, each module demonstrates powerful classification performance. Furthermore, EPMSI illustrates a new method to explore the miRNA sponge regulatory network for breast cancer by applying its superior performance.

Production and Purification of Artificial Circular RNA Sponges for Application in Molecular Biology and Medicine

Characterized by their covalently closed structure and thus an elevated stability compared to linear RNA molecules, circular RNAs (circRNAs) form a novel class of mainly non-coding RNAs. Although the biological functions of naturally occurring circRNAs are largely unknown, they were reported to act as molecular sponges, sequestering microRNAs (miRNAs), resulting in a de-repression of target mRNAs. Taking these characteristics of naturally occurring circRNAs into account, artificial circRNAs could be a potential tool in molecular biology and medicine. Using the Hepatitis C virus (HCV) as a model system, this application of artificial circular RNAs was demonstrated. The virus requires cellular miRNA miR-122 for its life cycle, and circRNAs specifically engineered to efficiently sequester this miRNA impacted viral propagation. Since in this context the production of engineered circRNA remains the limiting factor, we present a method to produce and efficiently purify artificial circRNA sponges (ciRS) in vitro. In this protocol we provide insights into a small-scale and large-scale production technique of artificial circular RNA sponges relying on in vitro transcription and RNA ligation.

Broad spectrum immunomodulatory effects of Anopheles gambiae microRNAs and their use for transgenic suppression of Plasmodium

Malaria, caused by the protozoan parasite Plasmodium and transmitted by Anopheles mosquitoes, represents a major threat to human health. Plasmodium’s infection cycle in the Anopheles vector is critical for transmission of the parasite between humans. The midgut-stage bottleneck of infection is largely imposed by the mosquito’s innate immune system. microRNAs (miRNAs, small noncoding RNAs that bind to target RNAs to regulate gene expression) are also involved in regulating immunity and the anti-Plasmodium defense in mosquitoes. Here, we characterized the mosquito’s miRNA responses to Plasmodium infection using an improved crosslinking and immunoprecipitation (CLIP) method, termed covalent ligation of endogenous Argonaute-bound RNAs (CLEAR)-CLIP. Three candidate miRNAs’ influence on P. falciparum infection and midgut microbiota was studied through transgenically expressed miRNA sponges (miR-SPs) in midgut and fat body tissues. MiR-SPs mediated conditional depletion of aga-miR-14 or aga-miR-305, but not aga-miR-8, increased mosquito resistance to both P. falciparum and P. berghei infection, and enhanced the mosquitoes’ antibacterial defenses. Transcriptome analysis revealed that depletion of aga-miR-14 or aga-miR-305 resulted in an increased expression of multiple immunity-related and anti-Plasmodium genes in mosquito midguts. The overall fitness cost of conditionally expressed miR-SPs was low, with only one of eight fitness parameters being adversely affected. Taken together, our results demonstrate that targeting mosquito miRNA by conditional expression of miR-SPs may have potential for the development of malaria control through genetically engineered mosquitoes.

Malaria is caused by the Plasmodium parasite that is transmitted by Anopheles mosquitoes. The mosquito’s innate immune system plays an important role in controlling parasite infection. We have identified mosquito microRNAs (miRNAs) that are involved in regulating mosquito immunity to parasite infection. Transgenic mosquitoes that deplete the immunity-related miRNAs aga-miR-14 or aga-miR-305 through miRNA sponges, show increased resistance to both human and rodent parasite infection, and enhanced antibacterial defenses. Depletion of aga-miR-14 or aga-miR-305 resulted in an increased expression of multiple immunity-related and anti-Plasmodium genes, and the overall fitness cost of transgenic mosquitoes upon depletion of aga-miR-14 or aga-miR-305 was negligible. We show that targeting mosquito miRNA by transgenic expression of miRNA sponges may have potential for the development of malaria control through genetically engineered mosquitoes.

Ischemia-reperfusion injury of brain induces endothelial-mesenchymal transition and vascular fibrosis via activating let-7i/TGF-βR1 double-negative feedback loop

Let-7i modulates the physical function and inflammation in endothelial cells (ECs). However, whether the let-7i of ECs involves in brain vasculature and ischemic stroke is unknown. Using inducible Cadherin5-Cre lineage-tracking mice, a loxp-RNA-sponge conditional knockdown of let-7 in ECs- induced increase of transforming growth factor-β receptor type 1 (TGF-βR1), endothelial-mesenchymal transition (endMT), vascular fibrosis, and opening of the brain-blood barrier (BBB). By this lineage-tracking mice, we found that ECs underwent endMT after transient middle cerebral artery occlusion (MCAO). Through specifically overexpressed let-7i in ECs, we found that it reduced TGF-βR1, endMT, and vascular fibrosis. Furthermore, this overexpression reduced the infarct volume and leakage of the BBB, and improved the neurological function. Further, the expression of let-7i decreased after MCAO, but was reversed by antagonist of TGF-βR1 or inhibition of Mek phosphorylation. And the inhibition of Mek attenuated the vascular fibrosis after MCAO. In summary, we concluded that ischemic stroke activates a let-7i/TGF-βR1 double-negative feedback loop, thereby inducing endMT and vascular fibrosis. These results suggest that endMT is a potential target for the treatment of cerebral vascular fibrosis.

MicroRNA Tough Decoy Knockdowns miR-195 and Represses Hypertrophy in Chondrocytes

Cartilage hypertrophy is a condition in which the cells are completely differentiated, and new morphological changes and mineralization prevent proper cellular functions. The occurrence of hypertrophy during differentiation fails current regenerative strategies for treatment. Strategies to minimize hypertrophy in chondrocytes are categorized into two levels of protein and gene. Among these strategies, one way to affect multiple pathways involved in the development of hypertrophy is to manage microRNA activity in cells. Recent miRNA profiling studies have shown that miR-195-5p upregulates through the transition from chondrogenic to hypertrophic state. Bioinformatics assessment of microRNA targets also indicates that several genes repressed by miR-195-5p play important roles in processes related to hypertrophy. The aim of this study was to develop a microRNA Tough Decoy to suppress miR-195-5p and investigate whether it can prevent a hypertrophic state in chondrocytes. The Tough Decoy (TUD) was designed and evaluated bioinformatically and then cloned into the pLVX-Puro plasmid. The TUD function was validated by Dual-Luciferase assay and qRT-PCR. After delivering TUD to C28/I2 chondrocytes cultured in a hypertrophic medium, hypertrophic differentiation was assessed by histochemical staining, quantitative RT-PCR of hypertrophy marker genes, and alkaline phosphatase activity. Results showed that the TUD could inhibit miRNA efficiently and downregulate hypertrophic markers such as RUNX2, alkaline phosphatase, and collagen 10 significantly compared with the control group. Alcian blue and alizarin red staining also demonstrated the optimal effect of gene constructs on tissue properties and mineralization of the TUD group. Delivering the miR-195-5p Tough Decoy to the cartilage cells can prevent the occurrence of hypertrophy in chondrocytes and could be considered as a candidate for the treatment of other diseases such as osteoarthritis.

Advances in the discovery of microRNA-based anticancer therapeutics: latest tools and developments

Introduction: MicroRNAs (miRNAs) are small endogenous non-coding RNAs that repress the expression of their target genes by reducing mRNA stability and/or inhibiting translation. miRNAs are known to be aberrantly regulated in cancers. Modulators of miRNA (mimics and antagonists) have emerged as novel therapeutic tools for cancer treatment.Areas covered: This review summarizes the various strategies that have been applied to correct the dysregulated miRNA in cancer cells. The authors also discuss the recent advances in the technical development and preclinical/clinical evaluation of miRNA-based therapeutic agents.Expert opinion: Application of miRNA-based therapeutics for cancer treatment is appealing because they are able to modulate multiple dysregulated genes and/or signaling pathways in cancer cells. Major obstacles hindering their clinical development include drug delivery, off-target effects, efficacious dose determination, and safety. Tumor site-specific delivery of novel miRNA therapeutics may help to minimize off-target effects and toxicity. Combination of miRNA therapeutics with other anticancer treatment modalities could provide a synergistic effect, thus allowing the use of lower dose, minimizing off-target effects, and improving the overall safety profile in cancer patients. It is critical to identify individual miRNAs with cancer type-specific and context-specific regulation of oncogenes and tumor-suppressor genes in order to facilitate the precise use of miRNA anticancer therapeutics.

Oct4-mediated reprogramming induces embryonic-like microRNA expression signatures in human fibroblasts

Oct4-mediated reprogramming has recently become a novel tool for the generation of various cell types from differentiated somatic cells. Although molecular mechanisms underlying this process are unknown, it is well documented that cells over-expressing Oct4 undergo transition from differentiated state into plastic state. This transition is associated with the acquisition of stem cells properties leading to epigenetically “open” state that is permissive to cell fate switch upon external stimuli. In order to contribute to our understanding of molecular mechanisms driving this process, we characterised human fibroblasts over-expressing Oct4 and performed comprehensive small-RNAseq analysis. Our analyses revealed new interesting aspects of Oct4-mediated cell plasticity induction. Cells over-expressing Oct4 lose their cell identity demonstrated by down-regulation of fibroblast-specific genes and up-regulation of epithelial genes. Interestingly, this process is associated with microRNA expression profile that is similar to microRNA profiles typically found in pluripotent stem cells. We also provide extensive network of microRNA families and clusters allowing us to precisely determine the miRNAome associated with the acquisition of Oct4-induced transient plastic state. Our data expands current knowledge of microRNA and their implications in cell fate alterations and contributing to understanding molecular mechanisms underlying it.

A single miRNA and miRNA sponge expression system for efficient modulation of miR-223 availability in mammalian cells

BACKGROUND

Hundreds of microRNAs (miRNAs), comprising small non-coding RNAs of 20-24 nucleotides, have been discovered, although the entirety of their biological functions is poorly understood. Overexpression or suppression approaches are commonly performed to investigate the function of specific miRNAs. In the present study, we focused on generating a lentiviral vector-based strategy that enables hsa-miR-223-3p (miR-223) overexpression and suppression in the target cells for functional analysis of this miRNA easily and rapidly.

METHODS

The sequence that gives rise to miR-223 and the sequence generating the sponge RNA with four binding sites for miR-223 were cloned in pLVX-shRNA2 vector. The functionality of the vector to overexpress miR-223 was evaluated by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) assays, whereas the post-transcriptional regulation exerted by miR-223 was evaluated by luciferase reporter assays in AD-293 cells. The anti-miR-223 sponge activity with one binding site for miR-223 (pmCherry-anti-miR-223) was confirmed by qRT-PCR and the restoration of its target (IKKα) was evaluated by western blot assays in Jurkat cells.

RESULTS

The pLVX-miR-223 vector is functional for over-expressing miR-223 and regulates the mRNA of MDR1/ABCB1 at the post-transcriptional level in AD-293 cells. The anti-miR-223 sponge with one miR-223 binding site efficiently modulates the miR-223 availability and not the one with four sites. The over-expression of anti-miR-223 correlated with a decrease in the levels of miR-223 and, consequently, with an increase in the expression level of the IKKα protein in Jurkat cells.

CONCLUSIONS

This single miRNA and miRNA sponge expression system specifically alters the availability of miR-223 in mammalian cells.