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MicroRNAs miR-186 and miR-150 Down-regulate Expression of the Pro-apoptotic Purinergic P2X7 Receptor by Activation of Instability Sites at the 3′-Untranslated Region of the Gene That Decrease Steady-state Levels of the Transcript

Department of Reproductive Biology, Case Western Reserve University, Cleveland, Ohio 44106, USA.
Journal of Biological Chemistry (Impact Factor: 4.57). 09/2008; 283(42):28274-86. DOI: 10.1074/jbc.M802663200
Source: PubMed

ABSTRACT The P2X7 receptor regulates cell growth through mediation of apoptosis. P2X7 levels are lower in cancer epithelial cells than in normal cells, and previous studies showed that expression of P2X7 was regulated post-transcriptionally. The objective of the study was to understand regulation of P2X7 mRNA stability. Overexpression of a reporter containing the full-length human P2X7 3'-untranslated region (3'-UTR) or reporters containing parts of the 3'-UTR-P2X7 were associated with increased abundance of the construct in normal cells and decreased abundance in cancer epithelial cells. Sequences within the 3'-UTR-P2X7, which are putative target sites for the microRNAs, miR-186 (middle segment) and miR-150 (distal segment), decreased the abundance of the P2X7 transcript. Overexpression in cancer cells of mutated miR-186 and miR-150 target sites was associated with lower levels of the reporter genes. In normal cells overexpression of the mutated miR-186 target site was associated with marked increased concentration, but overexpression of the miR-150 target site reporters, wild-type and mutant, did not change over time. Levels of miR-186 and miR-150 were higher in cancer than in normal cells, and treatment with miR-186 and miR-150 inhibitors increased P2X7 mRNA. In human embryonic kidney-293 cells heterologously expressing the full-length 3'-UTR-P2X7 luciferase reporter, miR-186 and miR-150 inhibitors increased luciferase activity, whereas miR-186 and miR-150 mimics decreased luciferase activity after actinomycin D treatment. These data suggest that increased expression of miR-186 and miR-150 in cancer epithelial cells decreases P2X7 mRNA by activation of miR-186 and miR-150 instability target sites located at the 3'-UTR-P2X7.

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    • ". We also detected upregulated miR- 181b-5p and −186-5p, which may suppress plasminogen activator inhibitor-1 in VSMCs (Chen et al. 2014) and promote apoptosis (Zhou et al. 2008), thus interfering with extracellular matrix degradation, and structural and functional changes in VSMCs. miR-155 is highly expressed in various cell types including VSMCs and endothelial cells (Faraoni et al. 2009). "
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    ABSTRACT: Atherosclerosis is an inflammatory disease with possible contributions from bacterial antigens. We aimed to investigate the role of oral bacteria as inducers of inflammatory cascades in smooth muscle cells from carotid endarterectomy patients (AthSMCs) and healthy controls (HSMCs). Inactivated Streptococcus mitis, S. sanguinis, S. gorgonii, Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis were used to stimulate inflammation in HSMCs and AthSMCs. Tumor necrosis factor-α (TNFα) was used as a positive control in all stimulations. Interleukin-6 (IL-6) levels were determined from cell culture supernatants and microRNA expression profiles from cells after 24 h of bacterial stimulation. Genome wide expression (GWE) analyses were performed after 5 h stimulation. All studied bacteria induced pro inflammatory IL-6 production in both SMCs. The most powerful inducer of IL-6 was A. actinomycetemcomitans (p < 0.001). Of the 84 studied miRNAs, expression of 9 miRNAs differed significantly (p ≤ 0.001) between HSMCs and AthSMCs stimulated with inactivated bacteria or TNFα. The data was divided into two groups: high IL-6 producers (A. actinomytectemcomititans and TNFα) and low IL-6 producers (streptococcal strains and P. gingivalis). The expression of 4 miRNAs (miR-181-5p, -186-5p, -28-5p and -155-5p) differed statistically significantly (p < 0.001) between healthy HSMCs and AthSMCs in the low IL-6 producer group. According to multidimensional scaling, two gene expression clusters were seen: one in HSMCs and one AthSMCs. Our results suggest that inactivated oral bacteria induce inflammation that is differently regulated in healthy and atherosclerotic SMCs.
    SpringerPlus 12/2015; 4(1). DOI:10.1186/s40064-015-0993-8
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    • "October 2011 | Volume 4 | Article 28 | 12 Table A4 | Additional targets of ChE-targeting miRs (common to more than one ChE). miR ID Validated target common to ACHE-R and AChE-S Hsa-miR-186 Pro-apoptotic P2 × 7 purinergic receptor(Zhou et al., 2008) "
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    Frontiers in Molecular Neuroscience 10/2011; 4:28. DOI:10.3389/fnmol.2011.00028 · 4.08 Impact Factor
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    Clinical Oncology and Cancer Research 02/2010; 7(1):22-26. DOI:10.1007/s11805-010-0022-1
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