Altered White Matter and microRNA Expression in a Murine Model Related to Williams Syndrome Suggests That miR-34b/c Affects Brain Development via Ptpru and Dcx Modulation

Williams syndrome (WS) is a multisystem neurodevelopmental disorder caused by a de novo hemizygous deletion of ~26 genes from chromosome 7q11.23, among them the general transcription factor II-I (GTF2I). By studying a novel murine model for the hypersociability phenotype associated with WS, we previously revealed surprising aberrations in myelination and cell differentiation properties in the cortices of mutant mice compared to controls. These mutant mice had selective deletion of Gtf2i in the excitatory neurons of the forebrain. Here, we applied diffusion magnetic resonance imaging and fiber tracking, which showed a reduction in the number of streamlines in limbic outputs such as the fimbria/fornix fibers and the stria terminalis, as well as the corpus callosum of these mutant mice compared to controls. Furthermore, we utilized next-generation sequencing (NGS) analysis of cortical small RNAs’ expression (RNA-Seq) levels to identify altered expression of microRNAs (miRNAs), including two from the miR-34 cluster, known to be involved in prominent processes in the developing nervous system. Luciferase reporter assay confirmed the direct binding of miR-34c-5p to the 3’UTR of PTPRU—a gene involved in neural development that was elevated in the cortices of mutant mice relative to controls. Moreover, we found an age-dependent variation in the expression levels of doublecortin (Dcx)—a verified miR-34 target. Thus, we demonstrate the substantial effect a single gene deletion can exert on miRNA regulation and brain structure, and advance our understanding and, hopefully, treatment of WS.

Genome-Wide Identification and Comparative Profiling of MicroRNAs Reveal Flavonoid Biosynthesis in Two Contrasting Flower Color Cultivars of Tree Peony

MicroRNA (miRNA)-mediated gene regulation is involved in various physiological processes in plants. Flower color is one of the vital ornamental traits of tree peony (Paeonia suffruticosa Andr.). However, the yellow-flowered tree peony cultivars are particularly rare. To elucidate the miRNA-mediated gene regulatory mechanism underlying yellow pigmentation in tree peony, we combined pigment assessment, miRNA identification, expression analysis, and gene functional verification in two contrasting flower color cultivars “High Noon” and “Roufurong.” Flavones/flavonols and anthocyanins were found to be the main contributors to the coloration of “High Noon” and “Roufurong” petals, respectively. Subsequently, miRNA analysis based on available genome data identified 9 differentially expressed miRNAs and 12 relevant target genes implicated in flavonoid biosynthesis. Their dynamic expression patterns determined the key role of mdm-miR156b-PsSPL2 module in yellow pigmentation of tree peony flowers. The sequence analysis and subcellular localization validated that PsSPL2 might function as a nuclear-localized transcription factor. Overexpression of PsSPL2 in tobacco resulted in a decrease of anthocyanin content and down-regulation of NtF3′H and NtDFR transcripts. PsSPL2-silenced petals exhibited lighter yellow color, and the contents of THC, Ap, and Ch decreased significantly. Meanwhile, expression levels of PsCHS, PsCHI, and PsF3H were significantly decreased in the petals with PsSPL2 silencing, while those of PsF3′H and PsDFR were remarkably increased. This study offers a novel insight into yellow pigmentation-related miRNA regulation network in tree peony, and further provides the valuable information on physiological changes during yellow coloring process of tree peony.

miR-515-3p, miR-623, miR-1272 and Notch3 protein as new biomarkers of Hepatocellular carcinoma

Backgrounds Hepatocellular carcinoma (HCC) is a diversity of hepatocellular neoplasms and is more prevalence in people with chronic liver disease and cirrhosis. It has been revealed that modification in miRNA regulation possibly will be elaborated in HCC pathogenesis. Materials and methods In this research 40 samples of HCC subjects and 40 samples of healthy liver were considered. Total RNA was obtained from paraffin-embedded tissue blocks and miR-515, miR-623 and miR-1272 gene expression levels were quantified by Real-Time Quantitative Reverse Transcription PCR. Likewise, the Notch protein quantity was assayed in ffpe materials by immunohistochemistry. Results Our study disclosed that Notch protein deals was ominously elevated in cancer cells than healthy cells (p<0.05). Data analysis also displayed that miR-515, miR-623 and miR-1272 expression levels were 3.8, 4.7, and 2.9 fold in normal tissues, respectively (p<0.05). Furthermore, it was found that expression levels of these genes are not dependent by hepatitis B and hepatic cirrhosis and it could be used as a marker of high specificity and sensitivity for the diagnosis of HCC. Discussions Our study demonstrated main role of miR-515, miR-623 and miR-1272 in HCC pathogenesis and similarly disclosed that these genes expression could be utilized in HCC prognosis.

miRNA Combinatorics and its Role in Cell State Control—A Probabilistic Approach

A hallmark of cancer evolution is that the tumor may change its cell identity and improve its survival and fitness. Drastic change in microRNA (miRNA) composition and quantities accompany such dynamic processes. Cancer samples are composed of cells’ mixtures of varying stages of cancerous progress. Therefore, cell-specific molecular profiling represents cellular averaging. In this study, we consider the degree to which altering miRNAs composition shifts cell behavior. We used COMICS, an iterative framework that simulates the stochastic events of miRNA-mRNA pairing, using a probabilistic approach. COMICS simulates the likelihood that cells change their transcriptome following many iterations (100 k). Results of COMICS from the human cell line (HeLa) confirmed that most genes are resistant to miRNA regulation. However, COMICS results suggest that the composition of the abundant miRNAs dictates the nature of the cells (across three cell lines) regardless of its actual mRNA steady-state. In silico perturbations of cell lines (i.e., by overexpressing miRNAs) allowed to classify genes according to their sensitivity and resilience to any combination of miRNA perturbations. Our results expose an overlooked quantitative dimension for a set of genes and miRNA regulation in living cells. The immediate implication is that even relatively modest overexpression of specific miRNAs may shift cell identity and impact cancer evolution.

Explore synergistic and competitive miRNA regulation mechanisms in the miRNA-mRNA regulatory network from the information decomposition perspective

Since multiple microRNAs can target 3' untranslated regions of the same mRNA transcript, it is likely that these endogenous microRNAs may form synergistic alliances, or compete for the same mRNA harbouring overlapping binding site matches. Synergistic and competitive microRNA regulation is an intriguing yet poorly elucidated mechanism. We here introduce a computational method based on the multivariate information measurement to quantify such implicit interaction effects between microRNAs. Our informatics method of integrating sequence and expression data is designed to establish the functional correlation between microRNAs. To demonstrate our method, we exploited TargetScan and The Cancer Genome Atlas data. As a result, we indeed observed that the microRNA pair with neighbouring binding site(s) on the mRNA is likely to trigger synergistic events, while the microRNA pair with overlapping binding site(s) on the mRNA is likely to cause competitive events, provided that the pair of microRNAs has a high functional similarity and the corresponding triplet presents a positive/negative 'synergy-redundancy' score.

MicroRNA Member TaMIR5062 in T. Aestivum Involves Plant Drought and Salt Acclimation via Regulating Physiological Processes Associated with Water Retention and ROS Homeostasis

microRNA members negatively regulate target genes via posttranscriptional cleavage or translation repression mechanisms, impacting on plant growth, development, and stress response. In this study, we characterized TaMIR5062, a miRNA member in T. aestivum, in mediating drought and salt responses. TaMIR5062 interacts with six target genes, including two encoding calmodulins, three coding for 4-oxalocrotonate tautomerases, and one for pumilio-family RNA binding domain protein. The TaMIR5062 transcripts were gradually upregulated in plants upon 27-h drought and salt treatments, whose induced expression under stress treatments was restored following the normal recovery condition. Tobacco (N. tabacum) lines transformed with TaMIR5062 modified growth traits under drought and salt treatments; the lines overexpressing miRNA (i.e., Sen 1 and Sen 2) improved growth traits (i.e., biomass, leaf area, and root length) whereas those with knockdown (Anti 1) alleviated growth features compared with wild type. These results suggested the critical role of TaMIR5062 in improving plant drought and salt tolerance. In line with growth traits in stress-challenged lines, improved leaf water retention (i.e., promoted stomata closing, water losing rate, and osmolytes) and ROS-associated parameters (higher SOD, CAT, and POD activities, etc.) were shown in Sen 1 and Sen 2 under stress conditions. Antioxidant enzyme (AE) genes NtMnSOD1, NtCAT, and NtPOD9 encoding SOD, CAT, and POD, respectively, enhanced transcription in Sen 1 and downregulated expression in Anti 1 challenged with drought and salt stress. These results suggested the improved ROS homeostasis mediated by TaMIR5062 associates modified expression of distinct AE genes. Quantities of genes functional into categories “biological process”, “cellular component”, and “molecular function” contribute to TaMIR5062-mediated osmotic stress adaptation by regulating distinct biological pathways (i.e., protein folding) and metabolisms (i.e., photosynthesis and isoprenoid biosynthesis), which impact on plant osmotic-regulation, ROS homeostasis, and stress defensiveness underlying miRNA regulation. TaMIR5062 is a valuable target for molecular breeding of drought-tolerant crop cultivars.

CHEK1: a hub gene related to poor prognosis for lung adenocarcinoma

Aim: The study aims to pinpoint hub genes and investigate their functions in order to gain insightful understandings of lung adenocarcinoma (LUAD). Methods: Bioinformatic approaches were adopted to investigate genes in databases including Gene Expression Omnibus, WebGestalt, STRING and Cytoscape, GEPIA2, Oncomine, Human Protein Atlas, TIMER2.0, UALCAN, cBioPortal, TargetScanHuman, OncomiR, ENCORI, Kaplan–Meier plotter, UCSC Xena, European Molecular Biology Laboratory – European Bioinformatics Institute Single Cell Expression Atlas and CancerSEA. Results: Five hub genes were ascertained. CHEK1 was overexpressed in a range of cancers, including LUAD. Promoter methylation, amplification and miRNA regulation might trigger CHEK1 upregulation, signaling poor prognosis. CHEK1 with its coexpressed genes were enriched in the cell cycle pathway. Intratumor heterogeneity of CHEK1 expression could be observed. Cell clusters with CHEK1 expression were more prone to metastasis and epithelial-to-mesenchymal transition. Conclusion: CHEK1 might potentially act as a prognostic biomarker for LUAD.

The impact of whole genome duplications on the human gene regulatory networks

This work studies the effects of the two rounds of Whole Genome Duplication (WGD) at the origin of the vertebrate lineage on the architecture of the human gene regulatory networks. We integrate information on transcriptional regulation, miRNA regulation, and protein-protein interactions to comparatively analyse the role of WGD and Small Scale Duplications (SSD) in the structural properties of the resulting multilayer network. We show that complex network motifs, such as combinations of feed-forward loops and bifan arrays, deriving from WGD events are specifically enriched in the network. Pairs of WGD-derived proteins display a strong tendency to interact both with each other and with common partners and WGD-derived transcription factors play a prominent role in the retention of a strong regulatory redundancy. Combinatorial regulation and synergy between different regulatory layers are in general enhanced by duplication events, but the two types of duplications contribute in different ways. Overall, our findings suggest that the two WGD events played a substantial role in increasing the multi-layer complexity of the vertebrate regulatory network by enhancing its combinatorial organization, with potential consequences on its overall robustness and ability to perform high-level functions like signal integration and noise control. Lastly, we discuss in detail the RAR/RXR pathway as an illustrative example of the evolutionary impact of WGD duplications in human.

Altered microRNAs in C3H10T1/2 cells induced by p.E95K mutant IHH signaling

Background Indian Hedgehog (IHH), an important cell signaling protein, plays a key regulatory role in development of cartilage and chondrogenesis. Earlier studies have shown that heterozygous missense mutations in IHH gene may cause brachydactyly type A1 (BDA1), an autosomal dominant inheritance disease characterized by apparent shortness or absence of the middle phalanges of all digits. MicroRNAs (miRNAs) have been found to be significant post-transcriptional regulators of gene expression and significantly influence the process of bone-development. Therefore, it is possible that miRNAs are involved in the mechanism underlying the development of BDA1. However, the relationship between miRNAs and the pathogenesis of BDA1 remains unclear. Methods In this study, we used microarray-based miRNA profiling to investigate the role of miRNAs in BDA1 by characterization of differentially expressed miRNAs in C3H10T1/2 cell line induced by wild type (WT) and p.E95K mutant (MT) IHH signaling. Results Our results identified 6 differentially expressed miRNAs between WT and control (CT) group and 5 differentially expressed miRNAs between MT and CT groups. In particular, miR-135a-1-3p was found to be a significantly differentially expressed miRNA between WT and CT group. Results of dual-luciferase reporter gene experiment successfully discovered Hoxd10 was one of the target gene of miR-135a-1-3p. Additionally, our pathway analysis revealed that the targets of these miRNAs of interest were highly involved with Runx1/2, Notch and collagen-related pathways. Conclusions Taken together, our findings provided important clue for future study of the process of miRNA-regulation in IHH signaling and novel insights into the regulatory role of miRNA in pathogenesis of BDA1.