MicroRNA control in the immune system: basic principles

miR-142 controls metabolic reprogramming that regulates dendritic cell activation

DCs undergo metabolic reprogramming from a predominantly oxidative phosphorylation (OXPHOS) to glycolysis to mount an immunogenic response. The mechanism underpinning the metabolic reprogramming remains elusive. We demonstrate that miRNA-142 (miR-142) is pivotal for this shift in metabolism, which regulates the tolerogenic and immunogenic responses of DCs. In the absence of miR-142, DCs fail to switch from OXPHOS and show reduced production of proinflammatory cytokines and the ability to activate T cells in vitro and in in vivo models of sepsis and alloimmunity. Mechanistic studies demonstrate that miR-142 regulates fatty acid (FA) oxidation, which causes the failure to switch to glycolysis. Loss- and gain-of-function experiments identified carnitine palmitoyltransferase -1a (CPT1a), a key regulator of the FA pathway, as a direct target of miR-142 that is pivotal for the metabolic switch. Thus, our findings show that miR-142 is central to the metabolic reprogramming that specifically favors glycolysis and immunogenic response by DCs.

Small molecules with big roles in microRNA chemical biology and microRNA-targeted therapeutics

MicroRNAs (miRNAs) are small, non-coding RNAs that post-transcriptionally regulate gene expression. Aberrant miRNA expression or function have close links with various human diseases. Therefore, therapeutic treatments with disease-associated miRNAs as targets are emerging. However, the intracellular miRNA networks are extremely complicated and poorly understood, which thus hinder the development of miRNA-targeted therapeutics. Small molecules that are able to regulate endogenous miRNAs hold great potential in both elucidation of miRNA networks and treatment of miRNA-related diseases. Herein, we summarize current strategies for discovery of small molecule modifiers of miRNAs, and we highlight aspects of miRNA cellular biology elucidated by using these small molecules and miRNA-targeted therapeutics realized by these small molecules. We envision that this area will expand dramatically in the near future and will ultimately contribute to a better understanding of miRNA-involved cellular processes and development of therapeutic agents for miRNA-associated diseases.

MicroRNAs and metastasis: small RNAs play big roles

MicroRNAs (miRNAs) are small non-coding RNAs regulating post-transcriptional gene expression. They play important roles in many biological processes under physiological or pathological conditions, including development, metabolism, tumorigenesis, metastasis, and immune response. Over the past 15 years, significant insights have been gained into the roles of miRNAs in cancer. Depending on the cancer type, miRNAs can act as oncogenes, tumor suppressors, or metastasis regulators. In this review, we focus on the role of miRNAs as components of molecular networks regulating metastasis. These miRNAs, termed metastamiRs, promote or inhibit metastasis through various mechanisms, including regulation of migration, invasion, colonization, cancer stem cell properties, epithelial-mesenchymal transition, and microenvironment. Some of these metastamiRs represent attractive therapeutic targets for cancer treatment.

Impact of Polypharmacy on Candidate Biomarker miRNomes for the Diagnosis of Fibromyalgia and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Striking Back on Treatments

Fibromyalgia (FM) and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) are diseases of unknown etiology presenting complex and often overlapping symptomatology. Despite promising advances on the study of miRNomes of these diseases, no validated molecular diagnostic biomarker yet exists. Since FM and ME/CFS patient treatments commonly include polypharmacy, it is of concern that biomarker miRNAs are masked by drug interactions. Aiming at discriminating between drug-effects and true disease-associated differential miRNA expression, we evaluated the potential impact of commonly prescribed drugs on disease miRNomes, as reported by the literature. By using the web search tools SM2miR, Pharmaco-miR, and repoDB, we found a list of commonly prescribed drugs that impact FM and ME/CFS miRNomes and therefore could be interfering in the process of biomarker discovery. On another end, disease-associated miRNomes may incline a patient's response to treatment and toxicity. Here, we explored treatments for diseases in general that could be affected by FM and ME/CFS miRNomes, finding a long list of them, including treatments for lymphoma, a type of cancer affecting ME/CFS patients at a higher rate than healthy population. We conclude that FM and ME/CFS miRNomes could help refine pharmacogenomic/pharmacoepigenomic analysis to elevate future personalized medicine and precision medicine programs in the clinic.

A self-assembled peptide nucleic acid-microRNA nanocomplex for dual modulation of cancer-related microRNAs

Here, we report a new strategy for the construction of a peptide nucleic acid-microRNA nanocomplex with dual function to simultaneously suppress oncogenic microRNAs and upregulate tumor-suppressive microRNAs in target cancer cells.

Common miRNA Patterns of Alzheimer's Disease and Parkinson's Disease and Their Putative Impact on Commensal Gut Microbiota

With the rise of Next-Generation-Sequencing (NGS) methods, Micro-RNAs (miRNAs) have achieved an important position in the research landscape and have been found to present valuable diagnostic tools in various diseases such as multiple sclerosis or lung cancer. There is also emerging evidence that miRNAs play an important role in the pathogenesis of neurodegenerative diseases such as Alzheimer's disease (AD) or Parkinson's disease (PD). Apparently, these diseases come along with changes in miRNA expression patterns which led to attempts from researchers to use these small RNA species from several body fluids for a better diagnosis and in order to observe disease progression. Additionally, it became evident that microbial commensals might play an important role for pathology development and were shown to have a significantly different composition in patients suffering from neurodegeneration compared with healthy controls. As it could recently be shown that secreted miRNAs are able to enter microbial organisms, it is conceivable that the host's miRNA might affect the gut microbial ecosystem. As such, miRNAs may inherit a central role in shaping the "diseased microbiome" and thereby mutually act on the characteristics of these neurodegenerative diseases. We have therefore (1) compiled a list of miRNAs known to be associated with AD and/or PD, (2) performed an in silico target screen for binding sites of these miRNA on human gut metagenome sequences and (3) evaluated the hit list for interesting matches potentially relevant to the etiology of AD and or PD. The examination of protein identifiers connected to bacterial secretion system, lipopolysaccharide biosynthesis and biofilm formation revealed an overlap of 37 bacterial proteins that were targeted by human miRNAs. The identified links of miRNAs to the biological processes of bacteria connected to AD and PD have yet to be validated via in vivo experiments. However, our results show a promising new approach for understanding aspects of these neurodegenerative diseases in light of the regulation of the microbiome.

Asthma diagnosis using integrated analysis of eosinophil microRNAs

BACKGROUND

Asthma is a syndrome characterized by airway inflammation and obstruction. Due to its heterogeneity, the difficulties in asthma diagnosis and treatment make the discovery of new biomarkers a focus of research. So, we determined the differential miRNA expression of eosinophils between healthy and asthmatic patients and to establish a differentially expressed miRNA profile detectable in sera for use as biomarker.

METHODS

MicroRNAs from peripheral eosinophils from healthy and asthmatic subjects were isolated and analyzed by next-generation sequencing and confirmed by quantitative PCR in 29 asthmatics and 10 healthy individuals. The levels of serum miRNAs were performed by quantitative PCR in 138 asthmatics and 39 healthy subjects. Regression analysis and Random Forest models were performed.

RESULTS

We found a set of miRNAs whose expression differs between eosinophils from asthmatics and healthy subjects. These miRNAs can classify asthmatics into two clusters that differed in the number of eosinophils and periostin concentration in serum. Some of these miRNAs were also confirmed in sera, as miR-185-5p which discriminates asthmatics from healthy subjects. Together with other two miRNAs, miR-185-5p allowed us to create a logistic regression model to discriminate better both conditions and a Random Forest model that can even sort the asthmatics into intermittent, mild persistent, moderate persistent, and severe persistent asthma.

CONCLUSION

Our data show that miRNAs profile in eosinophils can be used as asthma diagnosis biomarker in serum and that this profile is able to rank asthma severity.

The emerging role of epigenetics in human autoimmune disorders

Epigenetic pathways play a pivotal role in the development and function of the immune system. Over the last decade, a growing body of studies has been published out seeking to explain a correlation between epigenetic modifications and the development of autoimmune disorders. Epigenetic changes, such as DNA methylation, histone modifications, and noncoding RNAs, are involved in the pathogenesis of autoimmune diseases mainly by regulating gene expression. This paper reviews the importance of epigenetic alterations during the development of the most prevalent human autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), systemic sclerosis (SSc), Sjogren’s syndrome (SS), autoimmune thyroid diseases (AITD), and type 1 diabetes (T1D), aiming to provide new insights in the pathogenesis of autoimmune diseases and the possibility to develop novel therapeutic approaches targeting the epigenome.

Comparison of splenocyte microRNA expression profiles of pigs during acute and chronic toxoplasmosis

BACKGROUND

Toxoplasma gondii is an obligate intracellular parasite that infects humans and other warm-blooded animals. Previous quantitative proteomic analyses of infected host cells revealed that the expression of many host proteins is modulated by T. gondii infection. However, at present limited data are available on the differentially expressed miRNAs (DEMs) associated with the pathology and host immune responses induced by acute and chronic infection with T. gondii in pigs in vivo. In this study, high-throughput sequencing was used to investigate expression profiles of spleen miRNAs at 10, 25 and 50 days post-infection (DPI) in pigs infected with Chinese I genotype strain T. gondii isolated from a dead pig.

RESULTS

When compared to the control group, 34, 6 and 86 DEMs were found in spleens of infected pigs at 10, 25 and 50 DPI, respectively. Gene Ontology (GO) enrichment analysis of the target genes of DEMs showed that no GO terms were enriched at 25 DPI, whereas 28 and 241 GO terms, of which two and 215 were sample-specific, were significantly enriched at 10 and 50 DPI, respectively. The top 20 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of the target genes of DEMs included signal transduction, immune system, metabolism and diseases. miRNA-gene network analysis revealed that the DEMs played important roles in the host immune response to T. gondii infection by modulating expression levels of cellular immunity-related cytokines and immune-related C-type lectins.

CONCLUSION

Our results not only showed that host miRNA expression is altered by T. gondii but also revealed differences in the regulation of key biological processes and pathways involved in host responses to acute versus chronic T. gondii infection. This will aid future research into miRNA-target interactions during T. gondii infection in pigs and the development of novel therapies against T. gondii.

The B Cell Activation-Induced miR-183 Cluster Plays a Minimal Role in Canonical Primary Humoral Responses

Although primary humoral responses are vital to durable immunity, fine-tuning is critical to preventing catastrophes such as autoimmunity, chronic inflammation, and lymphomagenesis. MicroRNA (miRNA)-mediated regulation is particularly well suited for fine-tuning roles in physiology. Expression of clustered paralogous miR-182, miR-96, and miR-183 (collectively, 183c) is robustly induced upon B cell activation, entry into the germinal center, and plasmablast differentiation. 183c^GT/GT mice lacking 183c miRNA expression exhibit largely normal primary humoral responses, encompassing class switch recombination, affinity maturation, and germinal center reaction, as well as plasmablast differentiation. Our rigorous analysis included ex vivo class switch recombination and plasmablast differentiation models as well as in vivo immunization with thymus-dependent and thymus-independent Ags. Our work sways the debate concerning the role of miR-182 in plasmablast differentiation, strongly suggesting that 183c miRNAs are dispensable. In the process, we present a valuable framework for systematic evaluation of primary humoral responses. Finally, our work bolsters the notion of robustness in miRNA:target interaction networks and advocates a paradigm shift in miRNA studies.

MicroRNA Cross-Involvement in Autism Spectrum Disorders and Atopic Dermatitis: A Literature Review

Autism Spectrum Disorder (ASD) is a category of neurodevelopmental disturbances seriously affecting social skills, to which the scientific community has paid great attention in last decades. To date, their pathogenesis is still unknown, but several studies highlighted the relevance of gene-environment interactions in the onset of ASD. In addition, an immune involvement was seen in a wide number of ASD subjects, leading several researchers to hypothesize a possible common pathogenesis between ASD and immune disturbances, including Atopic Dermatitis (AD). In general, among potential contributing factors, microRNAs (miRNAs), small molecules capable of controlling gene expression and targeting mRNA transcripts, might represent one of the major circulating link, possibly unraveling the connections between neurodevelopmental and immune conditions. Under such premises, we conducted a systematic literature review, under the PRISMA guidelines, trying to define the panel of common miRNAs involved in both ASD and AD. The review retrieved articles published between January 1, 2005, and December 13, 2018, in PubMed, ScienceDirect, PsycARTICLES, and Google Scholar. We found a handful of works dealing with miRNAs in ASD and AD, with the most overlapping dysregulated miRNAs being miR-146 and miR-155. Two possible compounds are abnormally regulated in both ASD and AD subjects, possibly cross-contributing to the interactions between the two disorders, setting the basis to investigate more precisely the possible link between ASD and AD from another, not just clinical, perspective.

Circulating microRNAs as potential biomarkers of disease activity and structural damage in ankylosing spondylitis patients

Ankylosing spondylitis (AS) remains difficult to diagnose before irreversible damage to sacroiliac joint is noticeable. Circulating microRNAs have demonstrated to serve as diagnostic tools for several human diseases. Here, we analysed plasma microRNAs to identify potential AS biomarkers. Higher expression levels of microRNA (miR)-146a-5p, miR-125a-5p, miR-151a-3p and miR-22-3p, and lower expression of miR-150-5p, and miR-451a were found in AS versus healthy donors. Interestingly, higher miR-146a-5p, miR-125a-5p, miR-151a-3p, miR-22-3p and miR-451a expression was also observed in AS than psoriatic arthritis patients. The areas under the curve, generated to assess the accuracy of microRNAs as diagnostic biomarkers for AS, ranged from 0.614 to 0.781; the six-microRNA signature reached 0.957. Bioinformatics analysis revealed that microRNAs targeted inflammatory and bone remodeling genes, underlying their potential role in this pathology. Indeed, additional studies revealed an association between these six microRNAs and potential target proteins related to AS pathophysiology. Furthermore, miR-146a-5p, miR-125a-5p and miR-22-3p expression was increased in active versus non-active patients. Moreover, miR-125a-5p, miR-151a-3p, miR-150-5p and miR-451a expression was related to the presence of syndesmophytes in AS patients. Overall, this study identified a six-plasma microRNA signature that could be attractive candidates as non-invasive biomarkers for the AS diagnosis, and may help to elucidate the disease pathogenesis.

miR-206 as a Biomarker for Response to Mesalamine Treatment in Ulcerative Colitis

BACKGROUND

MicroRNAs (miRNAs) are important post-translational regulators. Elevated levels of miR-206 in ulcerative colitis (UC) were associated with suppression of anti-inflammatory A3 adenosine receptor (A3AR) expression. However, the relationship of miR-206 to histologic remission in UC patients remains unknown. This study correlates expression levels of miR-206 with histologic remission in patients treated via long-term mesalamine treatment to identify a possible mode of action for this mainstay drug for UC.

METHODS

Expression of miR-206 and its target A3AR were analyzed in HT29 cell line before and after mesalamine treatment (2 mM) at different time points (0, 4, 12, and 24 hours) by qRT-PCR and western blot analysis. Expression of miR-206 and pathological scores of colonoscopic biopsy specimens were studied in 10 UC patients treated with mesalamine treatment for 2 to 6 years.

RESULTS

miR-206 transcripts decreased 2.23-fold (P = 0.0001) 4 hours after 2 mM mesalamine treatment in HT29 colon cells compared with untreated controls. However, the mRNA/protein levels of A3AR increased by 4-fold (P = 0.04) and 2-fold, respectively, in same cells. miR-206 relative expression decreased significantly in patients treated with 4.8 g of mesalamine (P = 0.002) but not with 2.4 g (P = 0.35). Tissue assessment of sequential mesalamine-treated colonoscopic biopsies indicate a strong correlation between downregulation of miR-206 and histologic improvement (R = 0.9111).

CONCLUSION

Mesalamine treatment has an effect on epithelial miRNAs. Downregulation of miR-206 by long-term mesalamine treatment may confer a protective effect in inducing and maintaining histologic remission. Thus, miR-206 expression levels can be utilized as a possible biomarker for therapeutic response to mesalamine treatment.

Changes of microRNAs expression profiles from red swamp crayfish (Procambarus clarkia) hemolymph exosomes in response to WSSV infection

MicroRNAs (miRNAs) as short noncoding RNAs play important regulatory roles in diverse biological processes by degrading the target mRNAs, and could be delivered by exosomes. WSSV is a highly pathogenic and prevalent virus, and has brought high mortality of P. clarkia. Till present, no studies focus on the miRNAs changes in exosomes during WSSV infection. To understand the different virulence of WSSV on miRNAs expression in P. clarkia hemolymph exosome, the deep sequencing was performed to compare the small RNA libraries from the hemolymph exosome of P. clarkia individuals with or without WSSV infections. From the TEM observations, NTA and Western Blot analysis, the extracted exosomes were well identified with classic characteristics. The 209 conserved miRNAs and 250 novel miRNAs were identified from the small RNA libraries. In response to WSSV infection, there were about 98 miRNAs significantly up-regulated and 59 miRNAs significantly down-regulated. The target genes prediction, GO and KEGG enrichment analysis revealed that some target genes of P. clarkia miRNAs were grouped mainly into the categories of biological regulation, immune system process, signal pathway and other more functions. This is the first report of comprehensive identification of P. clarkia hemolymph exosome miRNAs being differentially regulated in response to WSSV infection. These results will help to understand the hemolymph exosome miRNAs response to different virulence WSSV infection.

MicroRNA-21 attenuates BDE-209-induced lipid accumulation in THP-1 macrophages by downregulating Toll-like receptor 4 expression

Growing evidence demonstrates a possible response of specific microRNA (miRNA) to environmental pollutant stimuli in multiple biological processes. We previously reported that a persistent organic pollutant, decabromodiphenyl ether (BDE-209), can enhance Toll-like receptor 4 (TLR4)-dependent lipid uptake in THP-1 macrophages; whether miRNAs are involved in this process remains unclear. In the present study, we investigated the levels of several miRNAs related to TLR4 signaling, including miRs-9, -21, -27b, -125b, -132, -146a, -147, -155, and -let-7e, in THP-1 macrophages after stimulation by BDE-209 and oxidized low-density lipoprotein. The results showed that the levels of miR-21 were significantly suppressed by BDE-209 at concentrations of 6.25, 12.5 and 25 μM, in a dose-dependent manner; whereas there was no significant changes for the other miRNAs investigated. Moreover, the suppression of miR-21 was accompanied by an upregulated TLR4 expression, at both mRNA and protein levels. Further analysis showed that the up-regulated TLR4 induced by BDE-209 was inhibited in macrophages transfected with miR-21 mimic; meanwhile opposite results were exhibited when an anti-miR-21 inhibitor was transfected to the macrophages. Additionally, transfection with miR-21 mimic effectively attenuated BDE-209-induced lipid accumulation in macrophages. Together, these data illustrate that miR-21 inhibits BDE-209-triggered lipid accumulation in macrophages through down-regulating TLR4 expression.

MiR-3470b promotes bovine ephemeral fever virus replication via directly targeting mitochondrial antiviral signaling protein (MAVS) in baby hamster Syrian kidney cells

BACKGROUND

Bovine ephemeral fever virus (BEFV), the causative agent of bovine ephemeral fever, is an economically important pathogen of cattle and water buffalo. MicroRNAs (miRNAs) are endogenous 21-23 nt small non-coding RNA molecules that binding to a multiple of target mRNAs and functioning in the regulation of viral replication including the miRNA-mediated antiviral defense. However, the reciprocal interaction between bovine ephemeral fever virus replication and host miRNAs still remain poorly understood. The aim of our study herein was to investigate the exact function of miR-3470b and its molecular mechanisms during BEFV infection.

RESULTS

In this study, we found a set of microRNAs induced by BEFV infection using small RNA deep sequencing, and further identified BEFV infection could significantly up-regulate the miR-3470b expression in Baby Hamster Syrian Kidney cells (BHK-21) after 24 h and 48 h post-infection (pi) compared to normal BHK-21 cells without BEFV infection. Additionally, the target association between miR-3470b and mitochondrial antiviral signaling protein (MAVS) was predicted by target gene prediction tools and further validated using a dual-luciferase reporter assay, and the expression of MAVS mRNA and protein levels was negatively associated with miR-3470b levels. Furthermore, the miR-3470b mimic transfection significantly contributed to increase the BEFV N mRNA, G protein level and viral titer, respectively, whereas the miR-3470b inhibitor had the opposite effect on BEFV replication. Moreover, the overexpression of MAVS or silencing of miR-3470b by its inhibitors suppressed BEFV replication, and knockdown of MAVS by small interfering RNA also promoted the replication of BEFV.

CONCLUSIONS

Our findings is the first to reveal that miR-3470b as a novel host factor regulates BEFV replication via directly targeting the MAVS gene in BHK-21 cells and may provide a potential strategy for developing effective antiviral therapy.

M2b macrophage polarization and its roles in diseases

Macrophages play an important role in a wide variety of physiologic and pathologic processes. Plasticity and functional polarization are hallmarks of macrophages. Macrophages commonly exist in two distinct subsets: classically activated macrophages (M1) and alternatively activated macrophages (M2). M2b, a subtype of M2 macrophages, has attracted increasing attention over the past decade due to its strong immune‐regulated and anti‐inflammatory effects. A wide variety of stimuli and multiple factors modulate M2b macrophage polarization in vitro and in vivo. M2b macrophages possess both protective and pathogenic roles in various diseases. Understanding the mechanisms of M2b macrophage activation and the modulation of their polarization might provide a great perspective for the design of novel therapeutic strategies. The purpose of this review is to discuss current knowledge of M2b macrophage polarization, the roles of M2b macrophages in a variety of diseases and the stimuli to modulate M2b macrophage polarization.

Resveratrol Attenuates Allergic Asthma and Associated Inflammation in the Lungs Through Regulation of miRNA-34a That Targets FoxP3 in Mice

Asthma is a chronic inflammatory disease of airways mediated by T-helper 2 (Th2) cells involving complex signaling pathways. Although resveratrol has previously been shown to attenuate allergic asthma, the role of miRNA in this process has not been studied. We investigated the effect of resveratrol on ovalbumin-induced experimental allergic asthma in mice. To that end, BALB/c mice were immunized with ovalbumin (OVA) intraperitoneally followed by oral gavage of vehicle (OVA-veh) or resveratrol (100 mg/kg body) (OVA-res). On day 7, the experimental groups received intranasal challenge of OVA followed by 7 days of additional oral gavage of vehicle or resveratrol. At day 15, all mice were euthanized and bronchioalveolar fluid (BALF), serum and lung infiltrating cells were collected and analyzed. The data showed that resveratrol significantly reduced IL-5, IL-13, and TGF-β in the serum and BALF in mice with OVA-induced asthma. Also, we saw a decrease in CD3+CD4+, CD3+CD8+, and CD4+IL-4+ cells with increase in CD4+CD25+FOXP3+ cells in pulmonary inflammatory cell infiltrate in OVA-res group when compared to OVA-veh. miRNA expression arrays using lung infiltrating cells showed that resveratrol caused significant alterations in miRNA expression, specifically downregulating the expression of miR-34a. Additionally, miR-34a was found to target FOXP3, as evidenced by enhanced expression of FOXP3 in the lung tissue. Also, transfection studies showed that miR-34a inhibitor upregulated FOXP3 expression while miR-34a-mimic downregulated FOXP3 expression. The current study suggests that resveratrol attenuates allergic asthma by downregulating miR-34a that induces increased expression of FOXP3, a master regulator of Treg development and functions.

Unveiling the regulation of NKT17 cell differentiation and function

Invariant natural killer T cells (iNKTs) are distinct from conventional T cells. iNKT cells express a semi-invariant T cell receptor (TCR) that can specifically recognize lipid antigens presented by CD1d, an MHC class I-like antigen-presenting molecule. Currently, iNKT cells are distinguished in three functionally distinct subsets. Each subset is defined by lineage-specifying factors: T-bet shapes the fate of NKT1 subset that mainly secretes IFNγ, Gata3 specifies the NKT2 subset that produces robustly IL-4 whereas RORγt seals the differentiation of NKT17 subset that secretes IL-17. In the present review, the focus is placed on the regulation of NKT17 specification and their function.

The c-Myc/miR17-92/PTEN Axis Tunes PI3K Activity to Control Expression of Recombination Activating Genes in Early B Cell Development

Appropriate PI3K signals generated by the antigen receptor are essential to promote B cell development. Regulation of recombination activating gene (RAG)-1 and RAG-2 expression is one key process that is mediated by PI3K to ensure developmental progression and selection. When PI3K signals are too high or too low, expression of RAGs does not turn off and B cell development is impaired or blocked. Yet, the mechanism which tunes PI3K activity to control RAG expression during B cell development in the bone marrow is unknown. Recently we showed that a c-Myc/miR17-92/PTEN axis regulates PI3K activity for positive and negative selection of immature B cells. Here, we show that the c-Myc/miR17-92/PTEN axis tunes PI3K activity to control the expression of RAGs in proB cells. Using different genetically engineered mouse models we show that impaired function of the c-Myc/miR17-92/PTEN axis alters the PI3K/Akt/Foxo1 pathway to result in dis-regulated expression of RAG and a block in B cell development. Studies using 38c-13 B lymphoma cells, where RAGs are constitutively expressed, suggest that this regulatory effect is mediated post-translationally through Foxo1.

Exploration of exosomal microRNA expression profiles in pigeon 'Milk' during the lactation period

Background

Pigeon crop has the unique ability to produce a nutrient rich substance termed pigeon ‘milk’ (PM), which has functional resemblance with the mammalian milk. Previous researches have demonstrated that a large number of exosomes and exosomal miRNAs exist in mammalian milk, and many of them are associated with immunity, growth and development. However, to date, little is known about the exosomes and exosomal miRNAs in PM.

Results

In this study, we isolated the exosomes from PM and used small RNA sequencing to investigate the distribution and expression profiles of exosomal miRNAs. A total of 301 mature miRNAs including 248 conserved and 53 novel miRNAs were identified in five lactation stages i.e. 1d, 5d, 10d, 15d, and 20d. From these, four top 10 conserved miRNAs (cli-miR-21-5p, cli-miR-148a-3p, cli-miR-10a-5p and cli-miR-26a-5p) were co-expressed in all five stages. We speculate that these miRNAs may have important role in the biosynthesis and metabolism of PM. Moreover, similar to the mammalian milk, a significant proportion of immune and growth-related miRNAs were also present and enriched in PM exosomes. Furthermore, we also identified 41 orthologous miRNAs group (giving rise to 81 mature miRNA) commonly shared with PM, human, bovine and porcine breast milk. Additionally, functional enrichment analysis revealed the role of exosomal miRNAs in organ development and in growth-related pathways including the MAPK, Wnt and insulin pathways.

Conclusions

To sum-up, this comprehensive analysis will contribute to a better understanding of the underlying functions and regulatory mechanisms of PM in squabs.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-5201-0) contains supplementary material, which is available to authorized users.

Similar dysregulation of lupus-associated miRNAs in peripheral blood mononuclear cells and splenic lymphocytes in MRL/lpr mice

Objective

MicroRNAs (miRNAs) play an important role in the pathogenesis of various autoimmune diseases including systemic lupus erythematosus (SLE; lupus). We have previously reported a common pattern of miRNA dysregulation in splenic lymphocytes from several mouse models of lupus. In this study, we investigated whether there is a similar miRNAs expression dysregulation in peripheral blood mononuclear cells (PBMCs) and splenocytes in a classical murine lupus model, MRL/lpr.

Method

PBMCs were isolated from blood samples of control MRL and lupus MRL/lpr mice aged 14-15 weeks by gradient centrifugation with Histopaque 1083 density media. miRNA TaqMan assays were performed to analyse the expression of 10 lupus-associated miRNAs including miR-182-96-183 cluster, miR-146a, miR-148a, miR-21, miR-31, miR-127, miR-155, and miR-411 in MRL and MRL/lpr PBMCs.

Result

In this study, we found that 8 out of 10 examined miRNAs (miR-21, miR-31, miR-127, miR-155, miR-96, miR-182, miR-183 and miR-411) were similarly dysregulated in both PBMCs and splenocytes of MRL/lpr mice when compared with MRL control mice. Only two miRNAs (miR-146a and miR-148a) showed different dysregulation pattern in the PBMCs and splenocytes of MRL/lpr mice. By comparing with the published miRNA data in human lupus, we demonstrated similarity in miRNA dysregulation in murine and human lupus PBMCs.

Conclusion

The findings in this study suggest that the miRNA changes observed in PBMCs largely reflect the miRNA dysregulation in cells from the lymphoid organ spleen. Analysis of miRNAs in PBMCs has an advantage over the splenocytes since it allows for monitoring the kinetics of lupus-associated miRNAs expression with peripheral blood cell samples during the development of the disease or after instituting treatment. The similar dysregulation of miRNAs in murine and human lupus PBMCs supports the importance and the feasibility of using murine lupus models to study the pathogenic and therapeutic function of miRNAs in human lupus.

Clustered miRNAs and their role in biological functions and diseases

MicroRNAs (miRNAs) are endogenous, small non-coding RNAs known to regulate expression of protein-coding genes. A large proportion of miRNAs are highly conserved, localized as clusters in the genome, transcribed together from physically adjacent miRNAs and show similar expression profiles. Since a single miRNA can target multiple genes and miRNA clusters contain multiple miRNAs, it is important to understand their regulation, effects and various biological functions. Like protein-coding genes, miRNA clusters are also regulated by genetic and epigenetic events. These clusters can potentially regulate every aspect of cellular function including growth, proliferation, differentiation, development, metabolism, infection, immunity, cell death, organellar biogenesis, messenger signalling, DNA repair and self-renewal, among others. Dysregulation of miRNA clusters leading to altered biological functions is key to the pathogenesis of many diseases including carcinogenesis. Here, we review recent advances in miRNA cluster research and discuss their regulation and biological functions in pathological conditions.

Potential Role of MicroRNA in the Anabolic Capacity of Skeletal Muscle With Aging

Age-induced loss of skeletal muscle mass and function, termed sarcopenia, may be the result of diminished response to anabolic stimulation. This review will explore the hypothesis that alterations in the expression of microRNA with aging contributes to reduced muscle plasticity resulting in impaired skeletal muscle adaptations to exercise-induced anabolic stimulation.

Involvement of the Negative Feedback of IL-33 Signaling in the Anti-Inflammatory Effect of Electro-acupuncture on Allergic Contact Dermatitis via Targeting MicroRNA-155 in Mast Cells

In this study, we aimed to investigate the effect of electro-acupuncture (EA) at the Zusanli acupoint (ST36) on interleukin (IL)-33-mediated mast cell activation. Firstly, 2,4-dinitrofluorobenzene (DNFB)-induced allergic contact dermatitis (ACD) in rats was developed with or without EA treatment. Then, rat peritoneal mast cells (RPMCs) were obtained and cultured in the presence of IL-33. EA treatment relieved ear swelling and reduced mast cell infiltration in the local inflammation area with DNFB challenge, accompanying the decrement of IL-33 production. RPMCs isolated from ACD rats with EA treatment showed significant downregulation of IL-6, TNF-α, IL-13, and MCP-1 production following IL-33 stimulation. However, there was no obvious difference in surface ST2 receptor expression among different groups. In addition, EA selectively altered IL-33 signaling, suppressing p38 phosphorylation as well as NF-κB- and AP-1-mediated transcription but not Akt phosphorylation. Importantly, EA lowered microRNA (miR)-155 expression in the RPMCs, which presented a positive correlation with IL-33-induced IL-6 production. Furthermore, overexpression of miR-155 in the RPMCs was established following miR-155 mimic transfection. RPMCs with the overexpressed miR-155 displayed an obvious increment of inflammatory cytokine and abrogated the inhibitive effect of EA on NF-κB- and AP-1-regulated transcription in response to IL-33 compared with those without transfected-miR-155. These findings demonstrate EA treatment inhibits NF-κB and AP-1 activation as well as promotes the negative feedback regulation of IL-33 signaling via targeting miR-155 in mast cells, which contribute to the anti-inflammatory effect of EA on DNFB-induced ACD in rats.

MicroRNA-451a in extracellular, blood-resident vesicles attenuates macrophage and dendritic cell responses to influenza whole-virus vaccine

The innate immune system is important for the efficacy of vaccines, but excessive innate immune responses can cause adverse reactions after vaccination. Extracellular vesicles (EVs) are enriched in the blood and can deliver functional RNAs, such as microRNAs (miRNAs), to recipient cells, thereby mediating intercellular communication. However, the role of EVs in controlling the innate immune responses to vaccines has not been fully elucidated. Here, we found that miR-451a is abundant in human serum EVs and that its presence in blood-circulating EVs affects the innate immune responses of macrophages and dendritic cells to inactivated whole-virus vaccines (WV) against influenza. miR-451a in human serum EVs was stable for a week in healthy subjects, and its levels gradually fluctuated over several months. miR-451a within serum EVs was internalized into serum-cultured macrophages and dendritic cells and reduced endogenous 14-3-3ζ protein levels and decreased the expression of type I IFN and interleukin 6 in response to WV stimulation. miR-451a levels in blood-circulating EVs were positively correlated with intracellular miR-451a levels in mouse splenic CD11c⁺ cells and inversely correlated with the innate immune response to inactivated WV in vivo These findings suggest that miR-451a in circulating EVs is internalized into recipient cells in vivo and that this internalization results in an attenuation of the innate immune response to WV. Moreover, a microarray analysis identified several other miRNAs that affect the macrophage response to inactivated WV. Our results reveal that miRNAs in circulating EVs significantly modify the responses of macrophages and dendritic cells to inactivated WV.

Differential Brain MicroRNA Expression Profiles After Acute and Chronic Infection of Mice With Toxoplasma gondii Oocysts

Brain microRNAs (miRNAs) change in abundance in response to Toxoplasma gondii infection. However, their precise role in the pathogenesis of cerebral infection with T. gondii oocyst remains unclear. We studied the abundance of miRNAs in the brain of mice on days 11 and 33 post-infection (dpi) in order to identify miRNA pattern specific to early (11 dpi) and late (33 dpi) T. gondii infection. Mice were challenged with T. gondii oocysts (Type II strain) and on 11 and 33 dpi, the expression of miRNAs in mouse brain was investigated using small RNA (sRNA) sequencing. miRNA expression was confirmed by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed to identify the biological processes, molecular functions, and cellular components, as well as pathways involved in infection. More than 1,500 miRNAs (1,352 known and 150 novel miRNAs) were detected in the infected and control mice. The expression of miRNAs varied across time after infection; 3, 38, and 108 differentially expressed miRNAs (P < 0.05) were detected during acute infection, chronic infection and chronic vs. acute infection, respectively. GO analysis showed that chronically infected mice had more predicted targets of dysregulated miRNAs than acutely infected mice. KEGG analysis indicated that most predicted targets were involved in immune- or disease-related pathways. Our data indicate that T. gondii infection alters the abundance of miRNAs in mouse brain particularly at the chronic stage, probably to fine-tune conditions required for the establishment of a latent brain infection.

Identification of microRNAs with heat stress responsive and immune properties in Marsupenaeus japonicus based on next-generation sequencing and bioinformatics analysis: Essential regulators in the heat stress-host interactions

Summer mortality syndrome is one of the most serious issue for Marsupenaeus japonicus aquaculture in China. Since it causes massive economic loss and threatens sustainability of M. japonicus aquaculture industry, thus, there is an urgent desire to reveal the heat stress-host interactions mechanisms that lead to mass mortalities of M. japonicus in hot summer months. MicroRNAs (miRNAs) are small noncoding RNAs that involved in regulation of diverse biological processes, including stress and immune response, and might serve as potential regulators in the heat stress-host interactions. In the present study, miRNAs with heat stress responsive and immune properties were identified and characterized in M. japonicus by small RNA sequencing and bioinformatics analysis. In total, 79 host miRNAs were identified, among which 15 miRNAs were differentially expressed in response to heat stress. Target genes prediction and function annotation revealed that a variety of host cellular processes, such as signal transduction, transcription, anti-stress response, ribosomal biogenesis, lipid metabolism, cytoskeleton, etc, were potentially subject to miRNA-mediated regulation in response to heat stress. Furthermore, a total of 30 host miRNAs that potentially involved in interaction with white spot syndrome virus (WSSV) were obtained via predicting and analyzing the target genes from WSSV. The results showed that a batch of WSSV genes that code for structural proteins and enzymes that are essential for WSSV infection and proliferation, such as envelope proteins, capsid proteins, immediate-early proteins, collagen-like protein, protein kinase, thymidylate synthetase, TATA-box bind protein, etc, were predicted to be targeted by host miRNAs. Several of the host miRNAs with predicted antiviral capacity were down-regulated under heat stress, indicating a repression of host miRNA-mediated antiviral immune response. This study highlighted the essential roles of host miRNAs in the heat stress-host interactions and provided valuable information for further investigation on the mechanism of miRNA-mediated heat stress and immune response of shrimp.

The effect of cellular context on miR-155-mediated gene regulation in four major immune cell types

Numerous microRNAs and their target mRNAs are co-expressed across diverse cell types. However, it is unknown whether they are regulated in a cellular context-independent or -dependent manner. Here, we explored transcriptome-wide targeting and gene regulation by miR-155, whose activation-induced expression plays important roles in innate and adaptive immunity. Through mapping of miR-155 targets using differential iCLIP, mRNA quantification with RNA-Seq, and 3′UTR usage analysis using polyadenylation (polyA)-Seq in activated miR-155-sufficient and -deficient macrophages, dendritic cells, T and B lymphocytes, we identified numerous targets differentially bound by miR-155. While alternative cleavage and polyadenylation (ApA) contributed to differential miR-155 binding to some transcripts, in a majority of cases identical 3′UTR isoforms were differentially regulated across cell types, suggesting ApA-independent and cellular context-dependent miR-155-mediated gene regulation. Our study provides comprehensive maps of miR-155 regulatory networks and offers a valuable resource for dissecting context-dependent and -independent miRNA-mediated gene regulation in key immune cell types.

Tissue-specific miRNA Expression Profiling in Mouse Heart Sections Using In Situ Hybridization

micro-RNAs (miRNAs) are single-stranded RNA transcripts that bind to messenger RNAs (mRNAs) and inhibit their translation or promote their degradation. To date, miRNAs have been implicated in a large number of biological and disease processes, which has signified the need for the reliable detection methods of miRNA transcripts. Here, we describe a detailed protocol for digoxigenin-labeled (DIG) Locked Nucleic Acid (LNA) probe-based miRNA detection, combined with protein immunostaining on mouse heart sections. First, we performed an in situ hybridization technique using the probe to identify miRNA-182 expression in heart sections from control and cardiac hypertrophy mice. Next, we performed immunostaining for cardiac Troponin T (cTnT) protein, on the same sections, to co-localize miRNA-182 with the cardiomyocyte cells. Using this protocol, we were able to detect miRNA-182 through an alkaline phosphatase based colorimetric assay, and cTnT through fluorescent staining. This protocol can be used to detect the expression of any miRNA of interest through DIG-labeled LNA probes, and relevant protein expression on mouse heart tissue sections.

MicroRNA-mediated regulation of T helper type 17/regulatory T-cell balance in autoimmune disease

T helper type 17 (Th17) cells and regulatory T (Treg) cells are two distinct T-cell subsets with opposite effects on immune functions. While Th17 cells are a key effector in the immune response and play critical roles in the development of autoimmunity and inflammation, Treg cells orchestrate the overall immune response and maintain peripheral immune tolerance by regulating the activity of the effector T cells. However, the developmental pathways for Th17 and Treg cells are reciprocally interconnected and there is a significant amount of plasticity between them. Disturbed Th17/Treg balance contributes to the development of autoimmune diseases, like experimental autoimmune encephalomyelitis and multiple sclerosis. MicroRNAs (miRNAs) are small non-coding RNA molecules that post-transcriptionally regulate gene expression. Recently, emerging evidence demonstrates that miRNAs play an important role in regulating the pathogenesis of autoimmune diseases through the modulation of Th17/Treg balance. This review will provide an overview of the dysregulated miRNAs and their functions in modulating the Th17/Treg balance in autoimmune diseases.

How to reprogram microglia toward beneficial functions

Microglia, brain cells of nonneural origin, orchestrate the inflammatory response to diverse insults, including hypoxia/ischemia or maternal/fetal infection in the perinatal brain. Experimental studies have demonstrated the capacity of microglia to recognize pathogens or damaged cells activating a cytotoxic response that can exacerbate brain damage. However, microglia display an enormous plasticity in their responses to injury and may also promote resolution stages of inflammation and tissue regeneration. Despite the critical role of microglia in brain pathologies, the cellular mechanisms that govern the diverse phenotypes of microglia are just beginning to be defined. Here we review emerging strategies to drive microglia toward beneficial functions, selectively reporting the studies which provide insights into molecular mechanisms underlying the phenotypic switch. A variety of approaches have been proposed which rely on microglia treatment with pharmacological agents, cytokines, lipid messengers, or microRNAs, as well on nutritional approaches or therapies with immunomodulatory cells. Analysis of the molecular mechanisms relevant for microglia reprogramming toward pro‐regenerative functions points to a central role of energy metabolism in shaping microglial functions. Manipulation of metabolic pathways may thus provide new therapeutic opportunities to prevent the deleterious effects of inflammatory microglia and to control excessive inflammation in brain disorders.

Increased expression of microRNAs, miR-20a and miR-326 in PBMCs of patients with type 1 diabetes

Type 1 diabetes (T1D) is an autoimmune disorder which is characterized by autoimmune attack on β cells of pancreas and lack of insulin. The involvement of microRNAs (miRNAs) in the development of immune system and their differential expression in various autoimmune diseases including T1D have been well established. In this study, the association between expression levels of miR-20a, miR-326 and T1D were evaluated. The expression levels of miR-20a and miR-326 were measured in the PBMCs of 21 T1D patients and 16 healthy controls using qPCR method. In silico analysis was also performed on targetome of miR-20a and miR-326. Both miR-20a (p value: 0.015) and miR-326 (p value: 0.005) were upregulated in the PBMCs of T1D patients compared to healthy controls. Furthermore, different dysregulated miR326-mRNA and miR20a-mRNA interactions were also suggested using integrative computational analysis. The expression level of miR-20a and miR-326 indicates significant association with T1D which suggests the possible regulatory effects of these non-coding RNAs in T1D.

miR-133b and miR-199b knockdown attenuate TGF-β1-induced epithelial to mesenchymal transition and renal fibrosis by targeting SIRT1 in diabetic nephropathy

Transforming growth factor-β1 (TGF-β1)-induced epithelial to mesenchymal transition (EMT) and renal fibrosis plays critical role in the development and progression of diabetic nephropathy (DN). Our study aimed to determine the detailed roles of miR-133b & miR-199b on TGF-β1-induced EMT & renal fibrosis in DN and its underlying mechanism. The expressions of miR-133b & miR-199b in OLETF rats, LETO rats & TGF-β1-treated human proximal tubule cell line (HK-2) were examined by qRT-PCR. Inhibition of miR-133b or miR-199b was realized in cells by transfection of lentivirus containing miR-133b inhibit or miR-199b inhibitor. The expression levels of collagen I (COL I), fibronectin (FN), α-smooth muscle actin (α-SMA), E-cadherin & sirtuin 1 (SIRT1) were detected by western blot and immunohistochemistry. Masson staining was conducted to estimate the degree of renal fibrosis. The interaction between SIRT1 and miR-133b, miR-199b was explored by luciferase reporter assay and RNA immunoprecipitation (RIP) assay. miR-133b and miR-199b were highly expressed in the renal cortex of diabetic OLETF rats and TGF-β1-treated HK-2 cells. EMT and renal fibrosis were induced in diabetic OLETF rats and TGF-β1-treated HK-2 cells. Inhibition of miR-133b and miR-199b attenuated EMT and renal fibrosis in diabetic OLETF rats and TGF-β1-treated HK-2 cells. In addition, SIRT1 was identified as a target of miR-133b & miR-199b in HK-2 cells. SIRT1 knockdown dramatically reversed the suppression on TGF-β1-induced EMT and renal fibrosis in HK-2 cells mediated by anti-miR-133b or anti-miR-199. Inhibition of miR-133b & miR-199b attenuated TGF-β1-induced EMT & renal fibrosis by upregulating SIRT1 shows that using different miRNAs is a potential strategy for the future treatment of DN.

The role of miR-29c/B7-H3 axis in children with allergic asthma

Background

MicroRNAs play roles in the pathogenesis of bronchial asthma. However, the mechanism of miR-29c in allergic asthma remains unclear. This study is to elucidate the regulation of Th cell differentiation by miR-29c in mononuclear macrophages.

Methods

A total of 52 children with asthma exacerbation and 26 children as controls were enrolled in the study. CD14⁺ monocytes were isolated from the peripheral blood. Differential expressions of microRNAs were evaluated using microarray analysis and miR-29c expression in monocytes was determined by qRT-PCR. The plasma B7-H3 was determined by ELISA. Transfection studies and luciferase reporter assay were performed to confirm target gene of miR-29c and its function.

Results

Compared to controls, 88 miRNAs in blood monocytes were up-regulated and 41 miRNAs down-regulated including miR-29c in asthma children. Children with asthma exacerbation had significantly lower level of miR-29c and higher level of plasma B7-H3 compared to controls (both P < 0.05). Functional studies based on luciferase reporter assay and immunofluorescence staining suggest that B7-H3 is the direct target of miR-29c and transfection anti-miR-29c into macrophages could enhance ROR-γt and GATA-3 expression in co-cultured CD4⁺ T cells and increase levels of IL-4 and IL-17 in supernatants.

Conclusion

The axis of miR-29c/B7-H3 plays an important role in children with asthma through regulating Th2/Th17 cell differentiation and may provide new targets for treatment of asthma.

miR-487a-3p upregulated in type 1 diabetes targets CTLA4 and FOXO3

AIMS

Type 1 diabetes (T1D) is an autoimmune disorder caused by the T-cell mediated destruction of the insulin-producing pancreatic beta cells. T1D is a consequence of complex processes, influenced by genetic, epigenetic and environmental factors. MicroRNAs (miRNAs) are small non-coding RNAs that target multiple mRNAs and regulate gene expression. The implication of miRNAs in T1D pathogenesis, as potential modulators of immune response genes, remains poorly defined. The aim of this study was to investigate the expression profile of miRNAs in new onset T1D and the impact of deregulated miRNAs on target genes.

METHODS

Total RNA from peripheral blood mononuclear cells of newly diagnosed T1D pediatric patients and age-matched controls was screened for disease-associated miRNAs by a microarray analysis, with subsequent validation by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). miRNA targets were identified by luciferase reporter assays.

RESULTS

The microarray analysis revealed 91 deregulated miRNAs (P < 0.05) in T1D group compared to non-diabetic controls. Within this group we observed one upregulated and seven downregulated miRNAs with fold change >2.0. qRT-PCR validation revealed overexpression of miR-487a-3p which has not been previously reported in the context of T1D. Luciferase reporter assays indicated CTLA4 and FOXO3 genes as miR-487a-3p targets.

CONCLUSION

Our study suggests that miR-487a-3p might repress CTLA4 and FOXO3 by binding to their 3'UTRs and contribute to the development of T1D.

Identification of exosome-like nanoparticle-derived microRNAs from 11 edible fruits and vegetables

Edible plant-derived exosome-like nanoparticles (EPDELNs) are novel naturally occurring plant ultrastructures that are structurally similar to exosomes. Many EPDELNs have anti-inflammatory properties. MicroRNAs (miRNAs) play a critical role in mediating physiological and pathological processes in animals and plants. Although miRNAs can be selectively encapsulated in extracellular vesicles, little is known about their expression and function in EPDELNs. In this study, we isolated nanovesicles from 11 edible fruits and vegetables and subjected the corresponding EPDELN small RNA libraries to Illumina sequencing. We identified a total of 418 miRNAs-32 to 127 per species-from the 11 EPDELN samples. Target prediction and functional analyses revealed that highly expressed miRNAs were closely associated with the inflammatory response and cancer-related pathways. The 418 miRNAs could be divided into three classes according to their EPDELN distributions: 26 "frequent" miRNAs (FMs), 39 "moderately present" miRNAs (MPMs), and 353 "rare" miRNAs (RMs). FMs were represented by fewer miRNA species than RMs but had a significantly higher cumulative expression level. Taken together, our in vitro results indicate that miRNAs in EPDELNs have the potential to regulate human mRNA.

Silencing miR-150 Ameliorates Experimental Autoimmune Encephalomyelitis

MiR-150 regulates maturation and differentiation of T cells but how it functions in multiple sclerosis (MS) is unclear. In miR-150 knockout (KO) mice, we examined the effect of miR-150 deletion on disease severity of experimental autoimmune encephalomyelitis (EAE), an animal model of MS. After deleting miR-150, EAE disease severity was reduced according to clinical score. Histological staining and MBP immunofluorescence staining revealed that miR-150 deletion limited the extent of inflammatory demyelination and axonal damage in the spinal cord. Flow cytometry showed that CD3+, CD4+, and CD8+ T cells were increased in WT-EAE mice, but miR-150 deletion significantly reversed EAE-mediated up-regulation of CD3+, CD4+, and CD8+ T cells and down-regulation of CD19+ B cells. In addition, miR-150 deletion reduced the mRNA expression of IL-1β, IL-6, IL-17, and TNF-α in spleen and spinal cord after EAE induction. Thus, miR-150 deletion reduces EAE severity and demyelination, probably through inhibiting the activated immune response and the inflammation in the central nervous system.

miRNAs in Insects Infected by Animal and Plant Viruses

Viruses vectored by insects cause severe medical and agricultural burdens. The process of virus infection of insects regulates and is regulated by a complex interplay of biomolecules including the small, non-coding microRNAs (miRNAs). Considered an anomaly upon its discovery only around 25 years ago, miRNAs as a class have challenged the molecular central dogma which essentially typifies RNAs as just intermediaries in the flow of information from DNA to protein. miRNAs are now known to be common modulators or fine-tuners of gene expression. While recent years has seen an increased emphasis on understanding the role of miRNAs in host-virus associations, existing literature on the interaction between insects and their arthropod-borne viruses (arboviruses) is largely restricted to miRNA abundance profiling. Here we analyse the commonalities and contrasts between miRNA abundance profiles with different host-arbovirus combinations and outline a suggested pipeline and criteria for functional analysis of the contribution of miRNAs to the insect vector-virus interaction. Finally, we discuss the potential use of the model organism, Drosophila melanogaster, in complementing research on the role of miRNAs in insect vector-virus interaction.

Profiling of Microrna Expression within the Cells of Peripheral Blood Mononuclear after an Infection with Serotype-2 of Dengue Virus: Preliminary Study

The role of microRiboNucleic Acids (miRNA), a small-non coding RNA has been associated with immune regulation in various viral infectionincluding dengue infection. The microRNA will bind a specific protein target in order to encourage an explosive expression of various cytokines, known as cytokines storm in Dengue infection.The objective of this study aimed to determine and evaluate themicroRNAs profile expression withinperipheral blood mononuclear cells having been infected with one of the dengue virus serotype.To obtained the PBMCs from a healthy donor, Ficoll density gradient centrifugation was used to isolate the PBMCs and then followed infecting it with a DENV-2 clinical isolate. Prior to PBMCs isolation, the virus has been propagated and having titration to get an optimal virus titer. We conducted the infection at the multiplication of infections 4 PFU/106 cells.MiRCURYLNATMExiqon was utilized on purpose to extract the RNA. Quantitative Real-Time PCR was applied in order for the miRNAs relative expression to be measured. The preliminary result reveals that miR-150, miR-146a, hsa-let-7e expression were increased 1.74 folds, 2 folds, and 1.49 foldsrespectively at 12 hours post-infection on PBMCs upon DENV-2 infection.The expression of microRNAswas discovered to behigher inPBMCsat the time of infection withDENV-2.ThemiRNAs expression in the uninfected PMBCs was lower than that of the miRNA. This high expression of miRNAsin dengue infection may proceedto dengue infection pathogenesis.

Anti-Inflammatory MicroRNAs and Their Potential for Inflammatory Diseases Treatment

Inflammation is a complicated biological and pathophysiological cascade of responses to infections and injuries, and inflammatory mechanisms are closely related to many diseases. The magnitude, the complicated network of pro- and anti-inflammatory factors, and the direction of the inflammatory response can impact on the development and progression of various disorders. The currently available treatment strategies often target the symptoms and not the causes of inflammatory disease and may often be ineffective. Since the onset and termination of inflammation are crucial to prevent tissue damage, a range of mechanisms has evolved in nature to regulate the process including negative and positive feedback loops. In this regard, microRNAs (miRNAs) have emerged as key gene regulators to control inflammation, and it is speculated that they are fine-tune signaling regulators to allow for proper resolution and prevent uncontrolled progress of inflammatory reactions. In this review, we discuss recent findings related to significant roles of miRNAs in immune regulation, especially the potential utility of these molecules as novel anti-inflammatory agents to treat inflammatory diseases. Furthermore, we discuss the possibilities of using miRNAs as drugs in the form of miRNA mimics or miRNA antagonists.

Recent advances in vertebrate and invertebrate transgenerational immunity in the light of ecology and evolution

Parental experience with parasites and pathogens can lead to increased offspring resistance to infection, through a process known as transgenerational immune priming (TGIP). Broadly defined, TGIP occurs across a wide range of taxa, and can be viewed as a type of phenotypic plasticity, with hosts responding to the pressures of relevant local infection risk by altering their offspring's immune defenses. There are ever increasing examples of both invertebrate and vertebrate TGIP, which go beyond classical examples of maternal antibody transfer. Here we critically summarize the current evidence for TGIP in both invertebrates and vertebrates. Mechanisms underlying TGIP remain elusive in many systems, but while it is unlikely that they are conserved across the range of organisms with TGIP, recent insight into epigenetic modulation may challenge this view. We place TGIP into a framework of evolutionary ecology, discussing costs and relevant environmental variation. We highlight how the ecology of species or populations should affect if, where, when, and how TGIP is realized. We propose that the field can progress by incorporating evolutionary ecology focused designs to the study of the so far well chronicled, but mostly descriptive TGIP, and how rapidly developing -omic methods can be employed to further understand TGIP across taxa.

Non-Coding RNA Mediated Regulation of Allogeneic T Cell Responses After Hematopoietic Transplantation

Allogeneic bone marrow transplantation (BMT) is an effective therapy for several malignant and non-malignant disorders. The precise control of allogeneic T cells is critical for successful outcomes after BMT. The mechanisms governing desirable (graft-versus-leukemia) versus undesirable (graft-versus-host disease) allogeneic responses remain incompletely understood. Non-coding RNAs (ncRNA) are controllers of gene expression that fine-tune cellular responses. Multiple microRNAs (miRNAs), a type of ncRNA, have recently been shown to influence allogeneic T cell responses in both murine models and clinically. Here, we review the role of various miRNAs that regulate T cell responses, either positively or negatively, to allo-stimulation and highlight their potential relevance as biomarkers and as therapeutic targets for improving outcomes after allogeneic BMT.