P-30/BO-05 : MiRNA-145 administration attenuates thrombus formation in animal model of venous thrombosis

posted Jan 26, 2017, 6:02 AM by sourav ghosh   [ updated Jan 26, 2017, 6:33 AM ]

Anita Sahu1, Prabhash Kumar Jha1, Neha Gupta1, Tarun Tyagi1, Amit Prabhakar1, Tathagata Chatterjee2, Mohammad Zahid Ashraf1
(1) Defence Institute of Physiology & Allied Sciences (DIPAS), New Delhi, India (2) Army Hospital (Research & Referral), Delhi, India

Introduction: Venous thromboembolism (VTE) remains the third most common cardiovascular disease (CVD) with inexplicit pathogenesis. MiRNAs are small regulatory RNAs; emerge as a promising class of therapeutics in CVDs and malignancies. Targeting differentially expressed miRNAs could represent a new approach for the treatment of VTE also. In our study miR-145 expression decreased in thrombosed IVC of animal model of venous thrombosis (VT) as well as in plasma of VT patients. We assessed the therapeutic potential of miR-145 restoration in animal model.
Methods: Animals were subjected to a sham operation (n=10) or Inferior vena cava (IVC) ligation, n=14) for 6h to induce thrombus formation in IVC. Animals were intravenously administered miR-145 mimic or Negative control mimic. Coagulation markers were assessed by various assays post treatment, followed by molecular and histological analyses.
Results: Expression of miR-145 decreased in thrombosed IVC subjected to ligation compared to sham operated animals (~2 fold, n=5, P<0.01), but was increased in thrombosed IVC of animals administered with miR-145 mimic (~4 fold n=5, P<0.05). Restoration of miR-145 attenuated thrombus formation. Histology study of thrombus showed reduced thrombus formation and thrombus weight (35±5%, n=5, P<0.01). Furthermore, decrease in coagulation markers - Clotting time, prothrombin time, prothrombin F1+2, (all P<0.05, n=4-7/group) confirmed antithrombotic effect of miR-145 treatment. To elucidate the mechanisms underlying the miR-145 mediated antithrombotic effect, we performed bioinformatics analysis, luciferase reporter assay, and western-blotting. Our results showed that miR-145 negatively regulated tissue factor. Tissue Factor mRNA and activity were decreased in thrombosed IVC in treated animals (3 fold and 2 fold respectively, n=5, P<0.05).
Conclusion: Therapeutic administration of miR-145 attenuates the thrombus formation, decreased thrombogenesis by downregulation of tissue factor. In conclusion this study provides the first evidence that restoration of miR-145 could represent an attractive approach for the treatment of VTE.