An Overview of Two Old Friends Associated with Platelet Redox Signaling, the Protein Disulfide Isomerase and NADPH Oxidase

Abstract

Oxidative stress participates at the baseline of different non-communicable pathologies such as cardiovascular diseases. Excessive formation of reactive oxygen species (ROS), above the signaling levels necessary for the correct function of organelles and cells, may contribute to the non-desired effects of oxidative stress. Platelets play a relevant role in arterial thrombosis, by aggregation triggered by different agonists, where excessive ROS formation induces mitochondrial dysfunction and stimulate platelet activation and aggregation. Platelet is both a source and a target of ROS, thus we aim to analyze both the platelet enzymes responsible for ROS generation and their involvement in intracellular signal transduction pathways. Among the proteins involved in these processes are Protein Disulphide Isomerase (PDI) and NADPH oxidase (NOX) isoforms. By using bioinformatic tools and information from available databases, a complete bioinformatic analysis of the role and interactions of PDI and NOX in platelets, as well as the signal transduction pathways involved in their effects was performed. We focused the study on analyzing whether these proteins collaborate to control platelet function. The data presented in the current manuscript support the role that PDI and NOX play on activation pathways necessary for platelet activation and aggregation, as well as on the platelet signaling imbalance produced by ROS production. Our data could be used to design specific enzyme inhibitors or a dual inhibition for these enzymes with an antiplatelet effect to design promising treatments for diseases involving platelet dysfunction.

Targeting Cysteine Oxidation in Thrombotic Disorders

“…Evidence for oxidative stress-driven thrombosis is derived from multiple independent studies using targeted interruption of genes involved in oxidant regulation [51][52][53], pharmacologic inhibition of oxidant sources [54,55], chemical degraders or generators of oxidants [56,57], cellular assays that involve oxidants (e.g., platelet activation and endothelial cell-mediated procoagulant activity) [58][59][60], and animal models of thrombosis [57,61]. We focus on atherothrombosis, which is arterial thrombosis in the context of atherosclerosis, based on evidence from our lab and others that oxidative stress is prominent in dyslipidemia and other chronic atherogenic states and that redox cues in these settings are converted to a pro-thrombotic response [2,62,63].…”