Abstract 16479: Mir20a Regulates Tissue Factor Expression in Human Peripheral Blood Mononuclear Cells Exposed to High Glucose and Lipopolysaccharide
Introduction: Inflammation and coagulation are deeply interconnected phenomena, a mechanism amplified by Angiotensin(AT)II that upregulates Tissue Factor (TF), the major regulator of haemostasis and thrombosis through AT-1 receptor (R). Proinflammatory stimuli such as high glucose (HG) and lipopolysaccharide (LPS) induce TF expression by activating NFkB-mediated gene transcription and stimulating the intracellular synthesis of RAS components. Whether miRNAs participate to that process by post-transcriptional modulation of TF expression is unclear.
Hypothesis: We studied the role of miR-19a, miR-19b e miR-20a on TF expression of unpooled peripheral blood mononuclear cells (PBMCs) suspensions exposed to HG and lipopolysaccharide (LPS), per se and in presence of Olmesartan (OLM), an AT1R antagonist.
Methods: PBMCs, obtained from healthy volunteers through a discontinuous Ficoll/Hystopaque density gradient, were activated by LPS (0.1 μg/mL) and HG (50 mM). TF Pro-coagulant Activity (PCA) was assessed by a 1-stage clotting assay. miR-19a, miR-19b, miR-20a and RNU6B expression was assessed using specific TaqMan® MicroRNA Assays.
Results: As compared with normal glucose (NG, 11mM), HG increased TF PCA (from 0,0045±0,0013 to 0,03± 0,018 AU, n=10, p<0.001) and amplified the stimulatory effect of LPS on TF PCA (from 1,2±0,48 to 2.34±0.71 AU n=10, p<0.001), an effect inhibited by OLM (10-6 M) (-66±16%, n=10 p<0.001). miR-20a levels decreased in HG conditions (-57±39%, n=4, p<0.001) and further in presence of LPS (-32±30%, n=9, p<0.01); OLM reversed that inhibitory effect (+58±82%, n=9, p<0.01). miR-19a, on the other hand, was reduced only in HG conditions (-61±25%, n=4, p<0.001) while miR-19b was unaffected by either HG or LPS.
Conclusions: miR-20a may potentially contribute to post-transcriptional regulation of TF in PBMCs exposed to HG and LPS and AT1R blockade although either miR-19a or miR-19b do not appear to play a significant role in that specific context. The data open insofar unexplored and potentially relevant facets to our understanding of the complex mechanisms linking ATII, inflammation and coagulation.
Author Disclosures: C. Balia: None. M. Giordano: None. V. Scalise: None. S. Cianchetti: None. T. Neri: None. G. Fontanini: None. F. Basolo: None. A. Celi: None. R. Pedrinelli: None.
- © 2016 by American Heart Association, Inc.