Linc00299/miR-490-3p/AURKA axis regulates cell growth and migration in atherosclerosis.

Long non-coding RNA (lncRNA) plays a crucial role in regulating various cellular processes in atherosclerosis. The present study identified the regulation of Linc00299, via miR-490-3p targeting Aurora kinase A (AURKA), on migration and proliferation of endothelial cells and vascular smooth muscle cells (VSMCs) during atherosclerosis. The expression of RNAs was assessed by real-time PCR. The proliferation, apoptosis and migration were detected using MTT assay, Annexin V/PI staining and Transwell system, respectively. Bindings of Linc00299/miR-490-3p and subsequent miR-490-3p/AURKA were verified by luciferase and biotin pull-down assays. The protein expression of AURKA was detected by Western blotting. Expressions of Linc00299 and miR-490-3p were upregulated and downregulated in atherosclerosis patients, respectively. Both Linc00299 knockdown and miR-490-3p overexpression suppressed cell proliferation, increased apoptosis and inhibited migration of VSMCs and HUVECs. Linc00299 directly bound to miR-490-3p which targeted AURKA. The regulation of Linc00299 on expression of AURKA and proliferation and migration of VSMCs were dependent on miR-490-3p. Atherosclerosis-increased Linc00299 acts as a sponge of miR-490-3p to upregulate AURKA, and as a result increases proliferation and migration in VSMCs and HUVECs. Our study reveals an important effect of Linc00299/miR-490-3p/AURKA axis on regulating cell proliferation and migration in atherosclerosis.

Coxsackievirus B3 2A protease promotes encephalomyocarditis virus replication.

To determine whether 2A protease of the enterovirus genus with type I internal ribosome entry site (IRES) effect on the viral replication of type II IRES, coxsackievirus B3(CVB3)-encoded protease 2A and encephalomyocarditis virus (EMCV) IRES (Type II)-dependent or cap-dependent report gene were transiently co-expressed in eukaryotic cells. We found that CVB3 2A protease not only inhibited translation of cap-dependent reporter genes through the cleavage of eIF4GI, but also conferred high EMCV IRES-dependent translation ability and promoted EMCV replication. Moreover, deletions of short motif (aa13-18 RVVNRH, aa65-70 KNKHYP, or aa88-93 PRRYQSH) resembling the nuclear localization signals (NLS) or COOH-terminal acidic amino acid motif (aa133-147 DIRDLLWLEDDAMEQ) of CVB3 2A protease decreased both its EMCV IRES-dependent translation efficiency and destroy its cleavage on eukaryotic initiation factor 4G (eIF4G) I. Our results may provide better understanding into more effective interventions and treatments for co-infection of viral diseases.

VEGF promotes cardiac stem cells differentiation into vascular endothelial cells via the PI3K/Akt signaling pathway.

Recent research suggested that cardiac stem cells (CSCs) may have the clinical application for cardiac repair. However, their characteristics and the regulatory mechanisms of their growth and differentiation have not been fully investigated. Vascular endothelial growth factor (VEGF, VEGF-A) is a major regulator of physiological and pathological angiogenesis. But the homing role of VEGF for CSCs is unclear. In this report, CSCs were isolated, purified, and expanded in vitro from rat heart. VEGF, SU5416 (VEGF receptor blocker), and Wortmannin (PI3K/Akt signaling pathway inhibitor) were used for differentiation into vascular endothelial cells (VECs). Real-time qPCR was selected to confirm the role of PI3K/Akt signaling pathway in VECs differentiation from rat CSCs. The result of real-time qPCR demonstrated that PI3K/Akt signaling pathway plays an important role in rat CSCs differentiated into VECs. So, our research provides a theoretical basis and experimental evidence for therapeutic application of rat CSCs to treat cardiac repair.

Oxidative stress and cell-cycle change induced by coexposed PCB126 and benzo(a) pyrene to human hepatoma (HepG2) cells.

Benzo(a)pyrene (BaP) never exists in the environment as a single compound but always coexists with other chemicals. These chemicals may affect the toxicity of BaP. Our previous study confirmed that polychlorinated biphenyls (PCBs), which were recently found coexisting with BaP in various environmental media, dramatically enhanced the genotoxicity of BaP. But the known mechanisms associated with this phenomenon are limited. Because BaP's genotoxicity is highly associated with its ability to induce the oxidative stress, we propose that the coexistence of PCBs may enhance BaP's genotoxicity by affecting BaP-induced oxidative stress. In this study, the HepG2 cells were treated with either BaP (50 µM), 3,3',4,4',5-pentachlorobiphenyl (PCB126) (0.01, 0.1, 1, and 10 nM), or pretreated with PCB126 followed by a coexposure to BaP and PCB126. We found that the exposure to BaP alone effectively increased the level of reactive oxygen species (ROS), glutathione (GSH), malondialdehyde (MDA), and the percentage of cells in G0/G1 phase, but decreased the percentage of S-phase cells. Compared to BaP alone, coexposure to both BaP and PCB126 effectively enhanced the levels of ROS and MDA as well as the percentage of cells in S phase, but decreased the levels of GSH and percentage of cells in G0/G1 phase. Our findings suggest that increasing oxidative stress and impairing the normal cell-cycle control may be mechanisms by which PCB126 enhances the genotoxity of BaP exposure.