Identification of miRNAs as potential modulators of tissue factor expression in patients with systemic lupus erythematosus and antiphospholipid syndrome

Abstract

To cite this article: Teruel R, Pé rez-Sá nchez C, Corral J, Herranz MT, Pé rez-Andreu V, Saiz E, García-Barberá N, Martínez-Martínez I, Roldá n V, Vicente V, Ló pez-Pedrera C, Martínez C. Identification of miRNAs as potential modulators of tissue factor expression in patients with systemic lupus erythematosus and antiphospholipid syndrome. J Thromb Haemost 2011; 9: 1985-92.Summary. Background: Tissue factor (TF) is the main initiator of the coagulation cascade and elements that may upregulate its expression might provoke thrombotic events. Systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS) are autoimmune diseases characterized by a high TF expression in monocytes. Objectives: To examine the role of microRNAs (miRNAs) in TF expression and to evaluate their levels in SLE and APS patients. Methods: An in silico search was performed to find potential putative binding sites of miRNAs in TF mRNA. In vitro validation was performed transfecting cells expressing TF (THP-1 and MDA-MB-231) with oligonucleotide miRNA precursors and inhibitors. Additionally, reporter assays were performed to test for the binding of miR-20a to TF mRNA. Levels of miRNAs and TF were measured by quantitative (qRT-PCR) in patients with APS and SLE. Results: Overexpression of miRNA precursors, but not inhibitors, of two of the members of cluster miR-1792, for example miR-19b and miR-20a, in cells expressing TF decreased TF mRNA, protein levels, and procoagulant activity between 30% and 60%. Reporter assays showed that miR-20a binds to TF mRNA. Finally, we measured levels of miR-19b and miR-20a in monocytes from patients with APS and SLE and observed significantly lower miRNAs levels in comparison with healthy subjects inversely correlated with the levels of TF. Conclusions: Down-regulation of miR-19b and miR-20a observed in patients with SLE and APS could contribute to increased TF expression and thus provoke the hypercoagulable state characteristic of these patients.

PARP-14 combines with tristetraprolin in the selective posttranscriptional control of macrophage tissue factor expression

“…27 The stability of TF mRNA is known to be regulated by miR 19a/19b and by miR201/20b/106b, acting at distinct binding sites proximal to the conserved ARE engaged by the interaction of PARP-14 and TTP. [31][32][33] Using a luciferase mRNA stability reporter assay, we found that the 2 miR sites and the conserved ARE each contribute to reducing reporter activity in the assay, and have additive effects in combination. Clearly more work is now warranted to understand the molecular interactions between ARE-mediated and miR-mediated regulation of mRNA stability in this model, both under basal conditions and dynamically after LPS or cytokine activation.…”

“…[31][32][33] To examine the relative impact of the conserved 17-nucleotide AREs compared with the miR-A and miR-B sites, we established a luciferase mRNA stability reporter assay in RAW 264.7 cells. These are of mouse macrophage origin and are known to express hypophosphorylated TTP basally without stimulation 34 and to express PARP-14 (supplemental Figure 8).…”

Epigenetics and Systemic Lupus Erythematosus: Unmet Needs

“…For example, up to 40 % of SLE patients are persistently positive for aPL, even at high titre; however, less than one third of them actually display the clinical events. A similar group of aPL-positive asymptomatic carriers can also be found in subjects with no any underlying autoimmune disease and followed for a long period of time [74].…”

Can we withdraw anticoagulation in patients with antiphospholipid syndrome after seroconvertion?

“…Preliminary studies have shown that several members of the miR 17-92 cluster (miR-20a and miR-19b) regulate the expression of TF in monocytes from patients with APS and systemic lupus erythematosus (SLE) [27]. A reduction in their expression has been found to significantly correlate with the over-activation of TF.…”

“…A reduction in their expression has been found to significantly correlate with the over-activation of TF. The reduction in the expression of these miRNAs could therefore contribute to the prothrombotic state characteristic of APS and SLE patients [27]. Data gathered in recent years explored the relationship between three groups of antiphospholipid antibodies, not currently included in the classification criteria and the development of thrombotic events.…”