Circular RNA suppression of vascular smooth muscle apoptosis through the miR-545-3p/CKAP4 axis during abdominal aortic aneurysm formation.

BACKGROUND: Abdominal aortic aneurysms (AAA) are an important cause of cardiovascular deaths. The loss of vascular smooth muscle cells (VSMCs) has been reported to be related to the pathology of AAA. This study focused on investigating the function of circ_0002168 in VSMC apoptosis. METHODS: Levels of genes and proteins were measured by quantitative real-time-polymerase chain reaction (qRT-PCR) and Western blot. The growth of VSMCs was determined by using cell counting kit-8 assay, 5-ethynyl-2'-deoxyuridine (EdU) assay, flow cytometry and the evaluation of caspase-3 activity analysis, reactive oxygen species (ROS) production as well as lactate dehydrogenase (LDH) activity. The binding between miR-545-3p and circ_0002168 or Cytoskeleton-associated protein 4 (CKAP4) was confirmed by bioinformatics analysis, dual-luciferase reporter, RNA immunoprecipitation, and pull-down assays. RESULTS: Circ_0002168 decreased in the aortic tissues of patients with AAA. Functionally, ectopic overexpression of circ_0002168 dramatically induced proliferation and suppressed apoptosis in VSMCs. Mechanistically, circ_0002168 sequestered miR-545-3p to release CKAP4 expression via the ceRNA mechanism, indicating the circ_0002168/miR-545-3p/CKAP4 feedback loop in VSMCs. Increased miR-545-3p and a decreased CKAP4 expression were observed in patients with AAA. Rescue experiments showed that miR-545-3p reversed the protective effects of circ_0002168 on VSMC proliferation. Moreover, inhibition of miR-545-3p could restrain the apoptosis of VSMCs, which was abolished by CKAP4 silencing. CONCLUSION: Circ_0002168 has a protective effect on VSMC proliferation by regulating the miR-545-3p/CKAP4 axis, adding further understanding of the pathogenesis of AAA and a potential therapeutic approach in AAA management.

Characterization of Carbide Precipitation during Tempering for Quenched Dievar Steel.

Carbide precipitation and coarsening are investigated for quenched Dievar steel during tempering. Lath/lenticular martensite, retained austenite, lower bainite, auto-tempered, and larger spherical carbides are all observed in the as-quenched condition. The carbide precipitation sequence on tempering is ascertained to be: M8C7 + cementite → M8C7 + M2C + M7C3 → M8C7 + M7C3 + M23C6 → M8C7 + M7C3 + M23C6 + M6C; carbides become coarser on tempering, and the sizes for inter-lath carbides increase noticeably with increasing tempering temperatures due to the faster grain boundary diffusion, whereas the sizes for intra-lath carbides remain nearly constant. The rate of coarsening for carbides by tempering at 650 °C is much higher than those by tempering at 550 °C and 600 °C, due to the faster diffusion of alloying elements at higher temperatures.

Prediction of Functional Genes in Primary Varicose Great Saphenous Veins Using the lncRNA-miRNA-mRNA Network.

Background: Long noncoding RNAs (lncRNAs) have been widely suggested to bind with the microRNA (miRNA) sites and play roles of competing endogenous RNAs (ceRNAs), which can thus affect and regulate target gene and mRNA expression. Such lncRNA-related ceRNAs are identified to exert vital parts in vascular disease. Nonetheless, it remains unknown about how the lncRNA-miRNA-mRNA network functions in the varicose great saphenous veins. Methods: This study acquired the lncRNA and mRNA expression patterns from the GEO database and identifies the differentially expressed mRNAs and lncRNAs by adopting the R software "limma" package. Then, miRcode, miRDB, miRTarbase, and TargetScan were used to establish the miRNA-mRNA pairs and lncRNA-miRNA pairs. In addition, the lncRNA-miRNA-mRNA ceRNA network was constructed by using Cytoscape. Protein-protein interaction, Gene Ontology functional annotations, and Kyoto Encyclopedia of Genes and Genomes enrichment were carried out to examine the candidate hub genes, the functions of genes, and the corresponding pathways. Results: In line with the preset theory, we constructed ceRNA network comprising 12 lncRNAs, 38 miRNAs, and 149 mRNAs. Kyoto Encyclopedia of Genes and Genomes analysis indicated that the PI3K/Akt signaling pathway played a vital part in the development of varicose great saphenous veins. AC114730, AC002127, and AC073342 were significant biomarkers. At the same time, we predicted the potential miRNA, which may exert a significant influence on the varicose great saphenous veins, namely, miR-17-5p, miR-129-5p, miR-1297, miR-20b-5p, and miR-33a-3p. Conclusion: By performing ceRNA network analysis, our study detects new lncRNAs, miRNAs, and mRNAs, which can be applied as underlying biomarkers of varicose great saphenous veins and as therapeutic targets for the treatment of varicose great saphenous veins.

DsTRD: Danshen Transcriptional Resource Database.

Salvia miltiorrhiza has been comprehensively studied as a medicinal model plant. However, research progress on this species is significantly hindered by its unavailable genome sequences and limited number of expressed sequence tags in the National Center for Biotechnology Information database. Thus, a transcript database must be developed to assist researchers to browse, search, and align sequences for gene cloning and functional analysis in S. miltiorrhiza. In this study, the Danshen Transcriptional Resource Database (DsTRD) was built using 76,531 transcribed sequences assembled from 12 RNA-Seq transcriptomes. Among these 12 RNA-seq data, ten were downloaded from NCBI database. The remaining two were enced on the Hiseq2000 platform using the stem and hairy-root of S. miltiorrhiza. The transcripts were annotated as protein-coding RNAs, long non-coding RNAs, microRNA precursors, and phased secondary small-interfering RNA genes through several bioinformatics methods. The tissue expression levels for each transcript were also calculated and presented in terms of RNA-Seq data. Overall, DsTRD facilitates browsing and searching for sequences and functional annotations of S. miltiorrhiza. DsTRD is freely available at http://bi.sky.zstu.edu.cn/DsTRD/home.php.

MiR-224 promotes proliferation and migration of gastric cancer cells through targeting PAK4.

Although recent studies have shown the important role and overexpression of miR-224 in several tumors, its function in gastric cancer has not yet been defined. In the present study, we tried to confirm the result of microRNAs microarray and further investigated the functions of miR-224 in gastric cancer, and tried to find new downstream targets of miR-224. In this study, the level of miR-224 was measured in gastric cancer cells with the normal human gastric epithelial cell. The effects of miR-224 of on proliferation, migration, and target protein expression were evaluated by CCK8 assay, colony assay, transwell migration assay, western blotting. In addition, luciferase reporter plasmid was constructed to demonstrate the direct target of miR-224. Overexpression of miR-224 was detected in the gastric cancer cells, especially in SCG-7901. Exogenous miR-224 expression promoted the proliferation and migration of gastric cells and abrogating expression of miR-224 suppressed proliferation, and migration of SCG-7901 cells in vitro. Luciferase assays revealed that miR-224 directly targeted the 3'UTR of p21-activated kinase 4 (PAK4). The present study provides an experimental foundation for miR-224 as a potential tumor suppressor that may decrease PAK4 expression to inhibit gastric cancer cells and that in the future, targeting of this miRNA may provide a novel strategy for the diagnosis and treatment of patients with this lethal disease.