Evaluation of oxidized biomolecules and microRNAs association with primary antiphospholipid syndrome thrombosis-related

Author(s)

Camila de Oliveira Vaz

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Médicas
• Defense date: 2020-05-15

Examining board members

Patricia Moriel; Erich Vinicius De Paula; Daniel Dias Ribeiro

• Advisor: Fernanda Loureiro de Andrade Orsi; Patricia Moriel

Abstract

Introduction: Antiphospholipid syndrome (APS) is an autoimmune disease characterized by thromboembolic events (arterial or venous) or obstetric complications associated with the persistence of antiphospholipid antibodies (aPLs). The pathological mechanisms behind thrombosis in APS are not completely elucidated. Although aPLs are necessary to trigger hypercoagulability, they are not sufficient to cause thrombotic events and external factors play a role in the development of APS-related thrombosis. In this context, mechanisms such as oxidative stress and epigenetic influences could be represent mechanisms involved in thrombosis in APS. Oxidative stress occurs due to the imbalance between the production and elimination of reactive oxygen species, which generates a pro-inflammatory environment that can lead to hypercoagulability. Also, mechanisms of gene regulation by microRNAs (miRNAs) have been identified in inflammatory and atherothrombotic diseases. Aims: The main aim of this study was to evaluate the association of plasma levels of oxidative damage markers and a microRNA signature with APS-related thrombosis. Methodology: This is an observational case-control study, in which 70 patients with primary APS were included and matched by frequency of sex, age and race with 74 controls without thrombosis antecedents. For the assessment of oxidative stress, levels of malondialdehyde, 8-isoprostane, carbonylated proteins and the total antioxidant capacity of plasma samples from both groups were quantified by commercial CAYMAN CHEMICAL® kits. The identification of the differential signature of circulating microRNAs was performed using the microarray technique, using samples from 21 patients paired with 21 of the controls. Statistical analyzes were performed using the R statistical software (R Core Team, 2017) and SPSS for Windows version 20 (IBM Corp. Released 2011. IBM Armonk, NY: IBM Corp). We adopted a significance value at 0.05 for the analysis of oxidative damage markers and miRNAs as biomarkers, and at 0.001 for the differential analysis of miRNAs. Results: The APS patients majority was female, averaging 41 years of age and had had venous thrombosis spontaneously. Triple antibody positivity and arterial thrombosis were observed in 24.3% and 34.3% of the patients, respectively. The plasma concentrations of oxidative damage markers in patients with primary thrombotic APS was similar to that of controls, therefore we could not observe an association of these markers with APS-related thrombosis. In regard to epigenetic changes, 24 miRNAs differentially expressed in APS patients were identified. Several validated targets of these miRNAs are genes involved in pathways related to the induction and maintenance of prothrombotic and inflammatory state. We identified a signature of 5 miRNAs (hsa-miR-149-3p, hsa-miR-1273g-3p, hsa-miR-4687-3p, hsa-miR-4497 and hsa-miR-4516) that, together, have the capacity to discriminate thrombotic APS in relation to control (AU)

• FAPESP's process: 17/19251-4 - MicroRNAs and oxidized biomolecules as possible biomarkers of primary antiphospholipid syndrome
• Grantee: Camila de Oliveira Vaz
• Support Opportunities: Scholarships in Brazil - Master