Downregulation of microRNA-637 Increases Risk of Hypoxia-Induced Pulmonary Hypertension by Modulating Expression of Cyclin Dependent Kinase 6 (CDK6) in Pulmonary Smooth Muscle Cells.

BACKGROUND The objective of this study was to investigate the molecular mechanism by which miR-637 interferes with the expression of CDK6, which contributes to the development of pulmonary hypertension (PH) with chronic obstructive pulmonary disease (COPD). MATERIAL AND METHODS We used an online miRNA database to identify CDK6 as a virtual target of miR-637, and validated the hypothesis using luciferase assay. Furthermore, we transfected SMCs with miR-637 mimics and inhibitor, and expression of CDK6 was determined using Western blot and real-time PCR. RESULTS In this study, we identified CDK6 as a target of miR-637 in smooth muscle cells (SMCs), and determined the expression of miR-637 in SMCs from PH patients with COPD and normal controls. We also identified the exact miR-637 binding site in the 3'UTR of CDK6 by using a luciferase reporter system. The mRNA and protein expression levels of CDK6 in SMCs from PH patients with COPD were clearly upregulated compared with the normal controls. Cells exposed to hypoxia also showed notably increased CKD6 mRNA and protein expression levels, and when treated with miR-637 or CDK6 siRNA, this increase in CKD6 expression was clearly attenuated. Additionally, cell viability and cell cycle analysis showed that hypoxia markedly increased viability of SMCs by causing an accumulation in S phase, which was relieved by the introduction of miR-637 or CDK6 siRNA. CONCLUSIONS Our study proved that the CDK6 gene is a target of miR-637, and demonstrated the regulatory association between miR-637 and CDK6, suggesting a possible therapeutic target for PH, especially in patients with COPD.

An event-related brain potential study of children's conservation.

To investigate the relationship between cortical activation and conservation ability, 22 children were divided into two groups based on their performance on a standard Piagetian Conservation test. Visual evoked potentials were recorded while children performed a weight conservation task. A bilateral, frontal-distributed, broad late positive component at 900 ms differed between non-conserving and conserving children, with non-conservers having a larger amplitude. The significant interaction between conservation ability and hemisphere on the amplitude of this component suggests that inferior generators gradually move from central to right frontal-central while conservation level increases. The results indicate the existence of an ERP component that reflects weight conservation ability in children and a possible relationship between conservation ability and brain activation.

Hsa-miR-137, hsa-miR-520e and hsa-miR-590-3p perform crucial roles in Lynch syndrome.

The aim of the present study was to identify the differentially expressed microRNAs (DEMs) between Lynch syndrome (LS) and the normal colonic (N-C) control samples, predict the target genes (TGs) and analyze the potential functions of the DEMs and TGs. The miRNA expression dataset GSE30454, which included data of 13 LS and 20 N-C tissue samples, was downloaded from the Gene Expression Omnibus. The classical t-test in Linear Models for Microarray Data package was used for DEM identification. TG prediction was performed using 5 databases. The regulatory network of the DEMs and their TGs was constructed using Cytoscape. Functional and pathway enrichment analysis was performed. The transcription factors (TFs), tumor-associated genes (TAG) and tumor suppressor genes (TSGs) were then identified. Three key DEMs hsa-miR-137, hsa-miR-520e, and hsa-miR-590-3p were identified. Hsa-miR-520e and hsa-miR-137 had 4 common TGs, including SNF related kinase, metal-regulatory transcription factor 1 (MTF1), round spermatid basic protein 1 and YTH N6-methyladenosine RNA binding protein 3; hsa-miR-590-3p and hsa-miR-137 had 14 common TGs, including NCK adaptor protein 1 (NCK1), EPH receptor A7, and stress-associated endoplasmic reticulum protein 1; hsa-miR-590-3p and hsa-miR-520e had 12 common TGs, including Krüppel-like factor (KLF) 13, twinfilin actin binding protein 1, and nuclear factor I B. Through the functional and pathway enrichments analysis, MTF1 was involved in regulation of gene expression and metabolic processes, and sequence-specific DNA binding TF activity. KLF13 was involved in regulation of gene expression and regulation of cellular metabolic processes. NCK1 was enriched in the axon guidance pathway. In addition, the functional and pathway enrichment analysis showed certain TGs, such as hypoxia-inducible factor 1α, AKT serine/threonine kinase 2, and rapamycin-insensitive companion of mammalian target of rapamycin, participated in the mTOR signaling pathway. The 3 key DEMs hsa-miR-137, hsa-miR-520e, and hsa-miR-590-3p may have important roles in the process of LS.

Gene expression profiling of CD133-positive cells in coronary artery disease.

Gene expression profiles of CD133-positive cells from patients with coronary artery disease (CAD) were analyzed to identify key genes associated with cardiac therapy. Furthermore, the effect of exercise on gene expression was also investigated. Gene expression data set (accession number: GSE18608) was downloaded from the Gene Expression Omnibus, including blood samples from four healthy subjects (H), and from 10 patients with coronary artery disease at baseline (B) and after 3 months (3M) of exercise. Differential analysis was performed for H vs. B and H vs. 3M using limma package of R. Two­way cluster analysis was performed using the expression levels of the differentially expressed genes (DEGs) by package pheatmap of R. Functional enrichment analysis was applied on the DEGs using the Database for Annotation, Visualization and Integrated Discovery. Relevant small molecules were predicted using the Connectivity map database (cMap). A total of 131 and 71 DEGs were identified in patients with CAD prior to and following 3 months of exercise. The two groups of DEGs were compared and 44 genes overlapped. In cluster analysis with the expression levels of the common DEGs, patients with CAD could be well separated from the healthy controls. Functional enrichment analysis showed that response to peptide hormone stimulus and anti­apoptosis pathways were significantly enriched in the common DEGs. A total of 12 relevant small molecules were revealed by cMap based upon the expression levels of common DEGs, such as 5252917 and MG­262. Three months of exercise in part normalized the gene expression in CAD patients. The genes not altered by exercise may be the targets of small molecules, such as 5252917 and MG-262.

Global correlation analysis for microRNA and gene expression profiles in human obesity.

Obesity is an increasing health problem associated with major adverse consequences for human health. MicroRNAs (miRNAs), small endogenous non-coding RNAs, regulate the expression of genes that play roles in human body via posttranscriptional inhibition. To identify the miRNAs and their target genes involved in obesity, we downloaded the miRNA and gene expression profiles from gene expression omnibus (GEO) database and analyzed the differentially expressed miRNAs (DEMs) and differentially expressed genes (DEGs) in adipose tissues from obese subjects compared to those from non-obese subjects. Then, we constructed the miRNA-target interaction network and conducted functional enrichment analysis of DEGs, and the targets negatively correlated with DEMs. We identified a total of 16 miRNAs and 192 genes that showed a significantly different expression and 3002 miRNA-target interaction pairs, including 182 regulatory pairs in obesity. Target genes of DEMs were found mainly enriched in several functions, such as collagen fibril organization, extracellular matrix part, and extracellular matrix structural constituent. Moreover, hsa-miR-425 and hsa-miR-126 had a significant number of target genes and hsa-miR-16/COL12A1 and hsa-miR-634/SLC4A4 interaction pairs are significantly co-expressed, suggesting that they might play important roles in the pathogenesis of obesity. Our study provides a bioinformatic basis for further research of molecular mechanism in obesity.