Abundant miRNAs Research Articles

Skeletal myotube-derived extracellular vesicles enhance itaconate production and attenuate inflammatory responses of macrophages.

Macrophages play an important role in the innate immunity. While macrophage inflammation is necessary for biological defense, it must be appropriately controlled. Extracellular vesicles (EVs) are small vesicles released from all types of cells and play a central role in intercellular communication. Skeletal muscle has been suggested to release anti-inflammatory factors, but the effect of myotube-derived EVs on macrophages is unknown. As an anti-inflammatory mechanism of macrophages, the immune responsive gene 1 (IRG1)-itaconate pathway is essential. In this study, we show that skeletal muscle-derived EVs suppress macrophage inflammatory responses, upregulating the IRG1-itaconate pathway. C2C12 myoblasts were differentiated into myotubes and EVs were extracted by ultracentrifugation. Skeletal myotube-derived EVs were administered to mouse bone marrow-derived macrophages, then lipopolysaccharide (LPS) stimulation was performed and inflammatory cytokine expression was measured by RT-qPCR. Metabolite abundance in macrophages after addition of EVs was measured by CE/MS, and IRG1 expression was measured by RT-PCR. Furthermore, RNA-seq analysis was performed on macrophages after EV treatment. EVs attenuated the expression of LPS-induced pro-inflammatory factors in macrophages. Itaconate abundance and IRG1 expression were significantly increased in the EV-treated group. RNA-seq analysis revealed activation of the PI3K-Akt and JAK-STAT pathways in macrophages after EV treatment. The most abundant miRNA in myotube EVs was miR-206-3p, followed by miR-378a-3p, miR-30d-5p, and miR-21a-5p. Skeletal myotube EVs are supposed to increase the production of itaconate via upregulation of IRG1 expression and exhibited an anti-inflammatory effect in macrophages. This anti-inflammatory effect was suggested to involve the PI3K-Akt and JAK-STAT pathways. The miRNA profiles within EVs implied that miR-206-3p, miR-378a-3p, miR-30d-5p, and miR-21a-5p may be responsible for the anti-inflammatory effects of the EVs. In summary, in this study we showed that myotube-derived EVs prevent macrophage inflammatory responses by activating the IRG1-itaconate pathway.

Real-Time PCR Quantification of 87 miRNAs from Cerebrospinal Fluid: miRNA Dynamics and Association with Extracellular Vesicles after Severe Traumatic Brain Injury

Severe traumatic brain injury (sTBI) is an intracranial damage triggered by external force, most commonly due to falls and traffic accidents. The initial brain injury can progress into a secondary injury involving numerous pathophysiological processes. The resulting sTBI dynamics makes the treatment challenging and prompts the improved understanding of underlying intracranial processes. Here, we analysed how extracellular microRNAs (miRNAs) are affected by sTBI. We collected thirty-five cerebrospinal fluids (CSF) from five sTBI patients during twelve days (d) after the injury and combined them into d1-2, d3-4, d5-6 and d7-12 CSF pools. After miRNA isolation and cDNA synthesis with added quantification spike-ins, we applied a real-time PCR-array targeting 87 miRNAs. We detected all of the targeted miRNAs, with totals ranging from several nanograms to less than a femtogram, with the highest levels found at d1-2 followed by decreasing levels in later CSF pools. The most abundant miRNAs were miR-451a, miR-16-5p, miR-144-3p, miR-20a-5p, let-7b-5p, miR-15a-5p, and miR-21-5p. After separating CSF by size-exclusion chromatography, most miRNAs were associated with free proteins, while miR-142-3p, miR-204-5p, and miR-223-3p were identified as the cargo of CD81-enriched extracellular vesicles, as characterised by immunodetection and tunable resistive pulse sensing. Our results indicate that miRNAs might be informative about both brain tissue damage and recovery after sTBI.

Alterations in Abundance and Compartmentalization of miRNAs in Blood Plasma Extracellular Vesicles and Extracellular Condensates during HIV/SIV Infection and Its Modulation by Antiretroviral Therapy (ART) and Delta-9-Tetrahydrocannabinol (Δ9-THC).

Alterations in Abundance and Compartmentalization of miRNAs in Blood Plasma Extracellular Vesicles and Extracellular Condensates during HIV/SIV Infection and Its Modulation by Antiretroviral Therapy (ART) and Delta-9-Tetrahydrocannabinol (Δ9-THC).

Comparable Analysis of COMPSRA and Excerpt Pipelines for Mining Distinct Molecules of RNA

The COMPSRA and exceRpt pipelines that are used explicitly for quantifying RNAseq data were compared and evaluated in this study. In both pipelines, various tools are used to extract various kinds of RNAs from a given sample. Small RNA sequencing data from milk somatic cell samples from 12 buffaloes were compared using the COMPSRA and exceRpt analyses. The two selected pipelines were also evaluated from a variety of angles, including the length of time required for comparing the sequences, the types of supported databases for annotation, and the number of distinct RNAs produced as results. The output varies even though the pipelines are used for similar purposes, because different quantification techniques are used for transcriptomic data. When the two pipelines were compared, it became clear that both had drawbacks. For example, exceRpt's analysis time was very high, while COMPSRA's count of generated specific RNA was lower. In contrast to exceRpt, which detected abundance of tRNA, rRNA, miRNA, snRNA, snoRNA, and lncRNA, COMPSRA found circRNA and piRNA to have a higher level of diversity and abundance.

The Integrator complex regulates microRNA abundance through RISC loading.

MicroRNA (miRNA) homeostasis is crucial for the posttranscriptional regulation of their target genes during development and in disease states. miRNAs are derived from primary transcripts and are processed from a hairpin precursor intermediary to a mature 22-nucleotide duplex RNA. Loading of the duplex into the Argonaute (AGO) protein family is pivotal to miRNA abundance and its posttranscriptional function. The Integrator complex plays a key role in protein coding and noncoding RNA maturation, RNA polymerase II pause-release, and premature transcriptional termination. Here, we report that loss of Integrator results in global destabilization of mature miRNAs. Enhanced ultraviolet cross-linking and immunoprecipitation of Integrator uncovered an association with duplex miRNAs before their loading onto AGOs. Tracing miRNA fate from biogenesis to stabilization by incorporating 4-thiouridine in nascent transcripts pinpointed a critical role for Integrator in miRNA assembly into AGOs.

Endogenous miRNA-Based Innate-Immunity against SARS-CoV-2 Invasion of the Brain.

The severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2), the causative agent of COVID-19, possesses an unusually large positive-sense, single-stranded viral RNA (ssvRNA) genome of about ~29,903 nucleotides (nt). In many respects, this ssvRNA resembles a very large, polycistronic messenger RNA (mRNA) possessing a 5'-methyl cap (m7GpppN), a 3'- and 5'-untranslated region (3'-UTR, 5'-UTR), and a poly-adenylated (poly-A+) tail. As such, the SARS-CoV-2 ssvRNA is susceptible to targeting by small non-coding RNA (sncRNA) and/or microRNA (miRNA), as well as neutralization and/or inhibition of its infectivity via the human body's natural complement of about ~2650 miRNA species. Depending on host cell and tissue type, in silico analysis, RNA sequencing, and molecular-genetic investigations indicate that, remarkably, almost every single human miRNA has the potential to interact with the primary sequence of SARS-CoV-2 ssvRNA. Individual human variation in host miRNA abundance, speciation, and complexity among different human populations and additional variability in the cell and tissue distribution of the SARS-CoV-2 angiotensin converting enzyme-2 (ACE2) receptor (ACE2R) appear to further contribute to the molecular-genetic basis for the wide variation in individual host cell and tissue susceptibility to COVID-19 infection. In this paper, we review recently described aspects of the miRNA and ssvRNA ribonucleotide sequence structure in this highly evolved miRNA-ssvRNA recognition and signaling system and, for the first time, report the most abundant miRNAs in the control superior temporal lobe neocortex (STLN), an anatomical area involved in cognition and targeted by both SARS-CoV-2 invasion and Alzheimer's disease (AD). We further evaluate important factors involving the neurotropic nature of SARS-CoV-2 and miRNAs and ACE2R distribution in the STLN that modulate significant functional deficits in the brain and CNS associated with SARS-CoV-2 infection and COVID-19's long-term neurological effects.

A conserved SNP variation in the pre-miR396c flanking region in Oryza sativa indica landraces correlates with mature miRNA abundance

Plant precursor miRNAs (pre-miRNA) have conserved evolutionary footprints that correlate with mode of miRNA biogenesis. In plants, base to loop and loop to base modes of biogenesis have been reported. Conserved structural element(s) in pre-miRNA play a major role in turn over and abundance of mature miRNA. Pre-miR396c sequences and secondary structural characteristics across Oryza species are presented. Based on secondary structure, twelve Oryza pre-miR396c sequences are divided into three groups, with the precursor from halophytic Oryza coarctata forming a distinct group. The miRNA-miRNA* duplex region is completely conserved across eleven Oryza species as are other structural elements in the pre-miRNA, suggestive of an evolutionarily conserved base-to-loop mode of miRNA biogenesis. SNPs within O. coarctata mature miR396c sequence and miRNA* region have the potential to alter target specificity and association with the RNA-induced silencing complex. A conserved SNP variation, rs10234287911 (G/A), identified in O. sativa pre-miR396c sequences alters base pairing above the miRNA-miRNA* duplex. The more stable structure conferred by the ‘A10234287911’ allele may promote better processing vis-à-vis the structure conferred by ‘G10234287911’ allele. We also examine pri- and pre-miR396c expression in cultivated rice under heat and salinity and their correlation with miR396c expression.

Highly Effective Detection of Exosomal miRNAs in Plasma Using Liposome-Mediated Transfection CRISPR/Cas13a.

Exosomal miRNAs play a critical role in cancer biology and could be potential biomarkers for cancer diagnosis. However, due to the low abundance of miRNAs in the exosomes, recognizing and detecting disease-associated exosomal miRNAs in an easy-to-operate way remain a challenge. Herein, we used a liposome-mediated membrane fusion strategy (MFS) to transfect CRISPR/Cas13a into exosomes, termed MFS-CRISPR, directly measuring exosomal miRNAs in plasma. Using the MFS-CRISPR platform for detection of the exosomal miR-21, we achieve a linear range spanning four orders of magnitude (104-108 particles/mL) and the method is able to detect the exosomal miR-21 in as low as 1.2 × 103 particles/mL. The liposome-mediated MFS could confine fluorescent signals in fused vesicles, which can be used for exosome heterogeneity analysis. Moreover, MFS-CRISPR assay was evaluated by measuring clinical samples, and the difference of miR-21 expression of breast cancer patients and healthy donors was significant. Because of high sensitivity and simplicity, the proposed method could have promising clinical potential for cancer diagnosis and treatment monitoring.

Garlic-derived exosomes regulate PFKFB3 expression to relieve liver dysfunction in high-fat diet-fed mice via macrophage-hepatocyte crosstalk

BackgroundAlthough macrophage-mediated low-grade chronic inflammation and liver dysfunction have been found to be associated with the development of non-alcoholic fatty (NAFLD) and widely reported, but strategies and drugs targeting macrophages for the treatment of NAFLD are limited. Hypothesis/purposeGarlic-derived exosomes (GDE) can be useful for NAFLD due to its anti-inflammatory activity. Clarify whether GDE improves liver dysfunction through macrophage-hepatocyte crosstalk. MethodsGDE was isolated with PEG precipitation and ultracentrifuge. Inflammatory cytokines were detected by qRT-PCR and ELISA. Expression of 6-phosphofructo-2-kinase/fructose-2, 6-biphosphatase 3 (PFKFB3) was determined using qRT-PCR and western blot. Crosstalk between macrophages and hepatocytes was identified through a co-culture experiment. Small RNA sequencing and bioinformatic analysis were used to identify the key element of GDE regulating the expression of PFKFB3 gene. ResultsGDE regulated the expression of PFKFB3 to reduce the inflammatory response in LPS-treated differentiated THP-1 macrophages. Data from small RNA sequencing and bioinformatics analysis reveal that miR-396e, one of the most abundant miRNAs of GDE, is the key component to regulate PFKFB3 expression. Mechanistically, miR-396e-mediating PFKFB3 expression plays a crucial role in GDE inhibiting inflammatory response and enhancing lipid metabolism in hepatocytes via the macrophage-hepatocyte crosstalk. Notably, GDE supplementation reduced the inflammatory response and improved liver dysfunction in high-fat diet-fed mice. ConclusionGDE may be useful for improving the symptoms of NAFLD via macrophage-hepatocyte crosstalk and its role in PFKFB3 expression.

Longitudinal evaluation of serum microRNAs as biomarkers for neuroblastoma burden and therapeutic p53 reactivation.

Accurate assessment of treatment response and residual disease is indispensable for the evaluation of cancer treatment efficacy. However, performing tissue biopsies for longitudinal follow-up poses a major challenge in the management of solid tumours like neuroblastoma. In the present study, we evaluated whether circulating miRNAs are suitable to monitor neuroblastoma tumour burden and whether treatment-induced changes of miRNA abundance in the tumour are detectable in serum. We performed small RNA sequencing on longitudinally collected serum samples from mice carrying orthotopic neuroblastoma xenografts that were exposed to treatment with idasanutlin or temsirolimus. We identified 57 serum miRNAs to be differentially expressed upon xenograft tumour manifestation, out of which 21 were also found specifically expressed in the serum of human high-risk neuroblastoma patients. The murine serum levels of these 57 miRNAs correlated with tumour tissue expression and tumour volume, suggesting potential utility for monitoring tumour burden. In addition, we describe serum miRNAs that dynamically respond to p53 activation following treatment of engrafted mice with idasanutlin. We identified idasanutlin-induced serum miRNA expression changes upon one day and 11 days of treatment. By limiting to miRNAs with a tumour-related induction, we put forward hsa-miR-34a-5p as a potential pharmacodynamic biomarker of p53 activation in serum.

CircRNA-PI4KB Induces Hepatic Lipid Deposition in Non-Alcoholic Fatty Liver Disease by Transporting miRNA-122 to Extra-Hepatocytes.

Ectopic fat deposition in the liver, known as non-alcoholic fatty liver disease (NAFLD), affects up to 30% of the worldwide population. miRNA-122, the most abundant liver-specific miRNA, protects hepatic steatosis and inhibits cholesterol and fatty acid synthesis in NAFLD. Previously, we have shown that compared with its expression in healthy controls, miRNA-122 decreased in the liver tissue but gradually increased in the serum of patients with non-alcoholic fatty liver disease and non-alcoholic steatohepatitis, suggesting that miRNA-122 could have been transported to the serum. Here, we aimed to confirm and unravel the mechanism of transportation of miRNA-122 to extra-hepatocytes. Our findings showed a decrease in the intra-hepatocyte miRNA-122 and an increase in the extra-hepatocyte (medium level) miRNA-122, suggesting the miRNA-122 "escaped" from the intra-hepatocyte due to an increased extra-hepatocyte excretion. Using bioinformatics tools, we showed that miRNA-122 binds to circPI4KB, which was further validated by an RNA pull-down and luciferase reporter assay. The levels of circPI4KB in intra- and extra-hepatocytes corresponded to that of miRNA-122, and the overexpression of circPI4KB increased the miRNA-122 in extra-hepatocytes, consequently accomplishing a decreased protective role of miRNA-122 in inhibiting the lipid deposition. The present study provides a new explanation for the pathogenesis of the hepatic lipid deposition in NAFLD.

Suppression of RBFox2 by Multiple MiRNAs in Pressure Overload-Induced Heart Failure.

Heart failure is the final stage of various cardiovascular diseases and seriously threatens human health. Increasing mediators have been found to be involved in the pathogenesis of heart failure, including the RNA binding protein RBFox2. It participates in multiple aspects of the regulation of cardiac function and plays a critical role in the process of heart failure. However, how RBFox2 itself is regulated remains unclear. Here, we dissected transcriptomic signatures, including mRNAs and miRNAs, in a mouse model of heart failure after TAC surgery. A global analysis showed that an asymmetric alternation in gene expression and a large-scale upregulation of miRNAs occurred in heart failure. An association analysis revealed that the latter not only contributed to the degradation of numerous mRNA transcripts, but also suppressed the translation of key proteins such as RBFox2. With the aid of Ago2 CLIP-seq data, luciferase assays verified that RBFox2 was targeted by multiple miRNAs, including Let-7, miR-16, and miR-200b, which were significantly upregulated in heart failure. The overexpression of these miRNAs suppressed the RBFox2 protein and its downstream effects in cardiomyocytes, which was evidenced by the suppressed alternative splicing of the Enah gene and impaired E-C coupling via the repression of the Jph2 protein. The inhibition of Let-7, the most abundant miRNA family targeting RBFox2, could restore the RBFox2 protein as well as its downstream effects in dysfunctional cardiomyocytes induced by ISO treatment. In all, these findings revealed the molecular mechanism leading to RBFox2 depression in heart failure, and provided an approach to rescue RBFox2 through miRNA inhibition for the treatment of heart failure.

MicroRNAs behave differently to drought stress in drought-tolerant and drought-sensitive grape genotypes

Drought is a major environmental factor limiting grapevine production and quality. However, the roles of miRNAs in different grape varieties at the post-transcriptional level during drought are largely unknown. In this study, we investigated the miRNA abundance in a drought-sensitive grapevine (Vitis vinifera L. cv. Cabernet Sauvignon) (CS) and a drought-tolerant grapevine (Berlandiari Ressiguier No.2 × Rupestris Martin) (110R) in response to drought using Illumina sequencing. A total of 488 known and 892 novel miRNAs belonging to 48 miRNA families were identified in CS and 110-R, respectively. Various accumulation trends of miRNAs observed in the differential drought tolerance of grapevine genotypes were further confirmed using stem-loop qRT-PCR. The target transcripts are predominantly associated with biological processes, cellular components, and molecular functions. Several significantly different drought-responsive miRNAs were examined by β-glucuronidase reporter gene activity driven by miRNA promoters in transgenic lines. The results showed drought-induced downregulation of VvmiR169d and VvmiR398a expression and upregulation of VvmiR156b expression. Moreover, we noted that VvmiR156b overexpression significantly decreased primary root length and increased lateral root numbers in Arabidopsis lines and observed a higher relative growth rate in grape calli under drought treatment. Therefore, genotype-dependent stress-responsive regulation of miRNA expression contributes to the differential drought tolerance of grapevines, and this finding provides mechanistic insight into the vital roles of miRNAs in drought-stress environments in grapevines.

Identification of extremely GC-rich micro RNAs for RT-qPCR data normalization in human plasma.

We aimed at extending the repertoire of high-quality miRNA normalizers for reverse transcription-quantitative PCR (RT-qPCR) of human plasma with special emphasis on the extremely guanine-cytosine-rich portion of the miRNome. For high-throughput selection of stable candidates, microarray technology was preferred over small-RNA sequencing (sRNA-seq) since the latter underrepresented miRNAs with a guanine-cytosine (GC) content of at least 75% (p = 0.0002, n = 2). miRNA abundances measured on the microarray were ranked for consistency and uniformity using nine normalization approaches. The eleven most stable sequences included miRNAs of moderate, but also extreme GC content (45%-65%: miR-320d, miR-425-5p, miR-185-5p, miR-486-5p; 80%-95%: miR-1915-3p, miR-3656-5p, miR-3665-5p, miR-3960-5p, miR-4488-5p, miR-4497 and miR-4787-5p). In contrast, the seven extremely GC-rich miRNAs were not found in the two plasma miRNomes screened by sRNA-seq. Stem-loop RT-qPCR was employed for stability verification in 32 plasma samples of healthy male Caucasians (age range: 18-55years). In general, inter-individual variance of miRNA abundance was low or very low as indicated by coefficient of variation (CV) values of 0.6%-8.2%. miR-3665 and miR-1915-3p outperformed in this analysis (CVs: 0.6 and 2.4%, respectively). The eight most stable sequences included four extremely GC-rich miRNAs (miR-1915-3p, miR-3665, miR-4787-5p and miR-4497). The best-performing duo normalization factor (NF) for the condition of human plasma, miR-320d and miR-4787-5p, also included a GC-extreme miRNA. In summary, the identification of extremely guanine-cytosine-rich plasma normalizers will help to increase accuracy of PCR-based miRNA quantification, thus raise the potential that miRNAs become markers for psychological stress reactions or early and precise diagnosis of clinical phenotypes. The novel miRNAs might also be useful for orthologous contexts considering their conservation in related animal genomes.

Inhibition of osteosarcoma by European Mistletoe derived val-miR218

Aim: In recent years, there has been a growing interest in the therapeutic potential of plant-derived miRNAs, which have been considered new bioactive ingredients in medicinal plants. Viscum album L., commonly used as an adjuvant cancer therapy in central Europe, contains a large number of miRNAs associated with human diseases such as cancer, cardiovascular diseases, and neurological disorders. This study aimed to investigate whether mistletoe miRNAs, specifically val-miR218, exert anti-cancer activity against osteosarcoma. Methods: The anti-cancer effects of miRNAs from V. album L. were evaluated. The targets of val-miR218 were identified by RNA-seq. The mRNA and protein expression of the targets was confirmed by RT-qPCR and western blot analyses. The interaction between the val-miR218 and miRNA recognition elements (MREs) was validated by the dual-luciferase assay. The inhibitory effect of val-miR218 against osteosarcoma was investigated in vivo. Results: Among these abundant miRNAs in V. album L., val-miR218 showed high potential anti-cancer effects against osteosarcoma. To clarify its molecular mechanism of action, we sequenced val-miR218 associated RNAs and their down-regulated RNAs. As a result, 61 genes were considered the direct targets of val-miR218. Interestingly, these targets were related to essential cellular functions such as cell cycle, DNA replication, and cell morphology, suggesting that val-miR218 significantly inhibited cell growth and arrested osteosarcoma cells in G0/G1 phase by influencing basic cell activities. Mistletoe extracellular vesicles offered val-miR218 adequate protection and facilitated the uptake of val-miR281 by human cells. Moreover, val-miR218 showed significant anti-tumor effects in vivo. Conclusion: This study demonstrated the significant potential of val-miR218 regarding proliferation inhibition in various tumor cell lines in vitro and for osteosarcoma in vivo. Due to the increasing problems during chemotherapy, new therapeutic approaches are becoming more critical. The significant anti-cancer effects of medicinal plants derived miRNAs indicate a promising therapeutic strategy for treating cancer.

Integrated analysis of transcriptome, small RNA, and phytohormonal content changes between <i>Artemisia annua</i> Linn. and <i>Nicotiana benthamiana</i> Domin in heterogeneous grafting

Grafting, one of the most artificial propagation methods of plants, now is widely used in flower breeding, vegetable cultivation and stress response research. In order to discover the reason for success of heterograft and information exchange mechanisms, we used <italic>Artemisia annua</italic> (Aa) as scion and <italic>Nicotiana benthamiana</italic> (Nb) as rootstock to build a grafting model. After grafting 30 days co-growth, 7,794 DEGs (different expression genes) and 8,214 DEGs were identified in Aa scion and Nb rootstock, respectively. Most of the DEGs belong to defense response and signal transduction in scion and substance metabolism in rootstock, which indicate that the diverging response mechansim of grafted parts. Besides, 50 Nb genes and 20 Aa genes were detected in Aa scion and Nb rootstock, which were regarded as potentially active genes during graft process. The most abundant miRNAs are <italic>miR159</italic> and <italic>miR166</italic>, which may be closely related to their conservation and physiological functions. Besides, <italic>miR159</italic> and <italic>miR166</italic> could quickly respond to internal change, therefore the two miRNAs should be considered as biomarker of successful grafting models. And then, as simultaneously screened miRNAs, <italic>miR396</italic> and <italic>miR6149</italic> could be potential biomarker in Aa and Nb, respectively<italic>.</italic> Through the analysis of miRNA-target gene network in differentially expressed miRNAs, transcription factor R2R3-MYB, <italic>bHLH</italic>, <italic>GRAS</italic>, <italic>GAMYB</italic>, <italic>SBP-box</italic>, <italic>MADS-box</italic>, <italic>IIS</italic> in scion and <italic>NF</italic>-<italic>Y</italic> in rootstock were regarded as key genes involved in growth and development of grafted plants. The content of ABA, JA, CK was calculated in grafted plants and showed its respective functions.

Exosomes from Short-Term High-Fat or High-Sucrose Fed Mice Induce Hepatic Steatosis through Different Pathways

Obesity and other closely associated diseases, such as metabolic-associated fatty liver disease (MAFLD) and type 2 diabetes, give rise to a common biometric and metabolic phenotype resulting from a different etiopathogenesis. To characterize the first stages of metabolic dysfunction induced by either obesity or hepatic steatosis, we compared two animal models of short-term feeding with either high-fat (HFD) or high-sucrose (SAC) diets. Using transcriptomic, metabolic, and calorimetric analyses, we determined that a short-term HFD leads to obesity and then hepatic steatosis through lipid storage, whereas SAC increases gluconeogenesis and de novo lipogenesis, resulting in hepatic steatosis followed later by obesity. Plasma exosomal miRNA profiles differed between HFD and SAC mice, and the injection of exosomes from HFD or SAC mice reproduced some transcriptomic and metabolic features of the donor mice. Finally, we exploited our data to identify circulating miR-22-3p as a candidate biomarker for MAFLD patient stratification. In conclusion, dietary challenges affecting adipose or hepatic metabolism regulate the abundance of exosomal miRNAs in plasma, which in turn modulate gene expression, helping the organism to adapt.

Dual-AND Logic Gate-Based Strip Assay for Amplified Detection of Four miRNAs and Diagnosis of Lung Cancer.

The detection of circulating tumor microRNAs (miRNAs) holds great promise for the noninvasive and early-stage diagnosis of cancer. However, the low abundance of lung cancer-related miRNAs and the false-positive results of single miRNA detection limited the development of strip-based point-of-care testing methods in clinic. We developed a duplex-specific nuclease (DSN)-mediated and dual-AND logic gate-based triple-line lateral flow strip detection system for the rapid and simultaneous detection of four miRNAs of lung cancer in a single strip test. This system combines DSN-mediated signal amplification with AND logic gate-based simple signal output. Meanwhile, the limit of detection of this platform was calculated to be 26.51 fM. Furthermore, this assay was used to detect lung cancer-related miRNAs from serum in a homogeneous and separation-free format, which could discriminate lung cancer patients from healthy individuals with an accuracy of 100%. Our approach provides a simple and easy-to-handle method for the diagnosis of lung cancer in clinic.

Genes related to cell wall metabolisms are targeted by miRNAs in immature tomato fruits under drought stress.

The metabolism of tomato fruits changes when plants experience drought stress. In this study, we investigated changes in microRNA (miRNA) abundance and detected 32 miRNAs whose expression changes in fruit. The candidate target genes for each miRNA were predicted from the differentially expressed genes identified by transcriptome analysis at the same fruit maturation stage. The predicted targeted genes were related to cell wall metabolisms, response to pathogens, and plant hormones. Among these, we focused on cell wall metabolism-related genes and performed a dual luciferase assay to assess the targeting of their mRNAs by their predicted miRNA. As a result, sly-miR10532 and sly-miR7981e suppress the expression of mRNAs of galacturonosyltransferase-10 like encoding the main enzyme of pectin biosynthesis, while sly-miR171b-5p targets β-1,3-glucosidase mRNAs involved in glucan degradation. These results will allow the systematic characterization of miRNA and their target genes in the tomato fruit under drought stress conditions.

Circulating miR-29b decrease in response to sarcopenia in patients with cardiovascular risk factors in older Chinese.

Sarcopenia is a clinical syndrome characterized by a progressive and extensive decline in skeletal muscle mass, muscle strength, and function. Sarcopenia and cardiovascular diseases (CVDs) can coexist, which further decreases the quality of life of patients, and increases the mortality rate. MicroRNAs (miRNAs) are unique posttranscriptional regulators of gene expression whose function in aging-related sarcopenia and CVDs has recently begun to unravel. The aim of the present study is to investigate the relationship between sarcopenia and cardiovascular risk factors (CVRF) in the Chinese elderly and describe the circulating miRNAs in sarcopenia patients with the intention of identifying novel diagnostic and therapeutic tools. The well-established CVRF of diabetes, hypertension, and dyslipidemia were assessed. Multiple logistic regression analyses and linear regressions were used to evaluate the components of CVRF and the number of CVRF in elderly patients with sarcopenia. Moreover, we used real-time RT-PCR to measure the abundance of the CVRF-related miRNAs in the plasma of a cohort of 93 control and sarcopenia individuals, including miR-29b, miR-181a, and miR-494. We found that CVRF was associated with a high prevalence of sarcopenia in elderly Chinese populations After adjusting for potential confounders. Furthermore, hypertension and dyslipidemia, but not diabetes, were found to be significantly associated with sarcopenia. A linear increase in the prevalence of sarcopenia was found to be associated with the number of CVRF components in the elderly population. We found that plasma miR-29b levels were significantly down-regulated in response to sarcopenia in the elderly with CVRF. In particular, there was a remarkable correlation between miR-29b and appendicular skeletal muscle mass (ASM)/height2. Collectively, knowledge of CVRF, particularly hypertension and dyslipidemia, may help predict the risk of sarcopenia in the elderly. Our data also show that circulating miR-29b can be considered as possible biomarkers for sarcopenia, which may also be used in the CVD assessment of these patients. We found that the prevalence of sarcopenia was significantly proportional to the number of CVRF components. In particular, hypertension and dyslipidemia were significantly associated with a higher risk of sarcopenia in the adjusted models. Moreover, our study has been proven that c-miRNAs may be considered as possible biomarkers for sarcopenia as a new diagnostic tool to monitor response to treatment. There is also a pressing need for further research on sarcopenia and CVRF to understand their relationship and mechanism. These can provide more evidence to develop potential interventions to improve clinical outcomes.