Endogenous SOD2 (Superoxide Dismutase) Regulates Platelet-Dependent Thrombin Generation and Thrombosis During Aging

Autor: Vijay K. Sonkar, Alicia S. Eustes, Azaj Ahmed, Melissa Jensen, Mitali V. Solanki, Jagadish Swamy, Rahul Kumar, Trevor P. Fidler, Jon C.D. Houtman, Bryan G. Allen, Douglas R. Spitz, E. Dale Abel, Sanjana Dayal
Rok vydání: 2023
Předmět:
Zdroj: Arteriosclerosis, Thrombosis, and Vascular Biology. 43:79-91
ISSN: 1524-4636
1079-5642
DOI: 10.1161/atvbaha.121.317735
Popis: Background: Reactive oxygen species (ROS) contribute to platelet hyperactivation during aging. Several oxidative pathways and antioxidant enzymes have been implicated; however, their mechanistic contributions during aging remain elusive. We hypothesized that mitochondria are an important source of platelet ROS and that mitochondrial SOD2 (superoxide dismutase) protects against mitochondrial ROS-driven platelet activation and thrombosis during aging. Methods: We studied littermates of platelet-specific SOD2-knockout (SOD2 fl/fl Pf4Cre, pSOD2-KO) and control (SOD2 fl/fl ) mice at young (4–5 months) or old (18–20 months) ages. We examined agonist-induced platelet activation, platelet-dependent thrombin generation potential, and susceptibility to in vivo thrombosis. Results: Platelet α II b β3 activation, aggregation, and adhesion were increased to similar extents in aged mice of both genotypes compared with young mice. In contrast, the age-dependent increases in mitochondrial and total cellular ROS, calcium elevation, and phosphatidylserine exposure were augmented in platelets from pSOD2-KO mice compared with control mice. Aged pSOD2-KO mice showed increased platelet-dependent thrombin generation compared with aged control mice. In vivo, aged pSOD2-KO mice exhibited enhanced susceptibility to carotid artery and pulmonary thrombosis compared to aged control mice. Adoptive transfer of platelets from aged pSOD2-KO but not aged control mice increased thrombotic susceptibility in aged host mice, suggesting a prothrombotic effect of platelet pSOD2 deficiency. Treatment with avasopasem manganese (GC4419), a SOD mimetic, decreased platelet mitochondrial pro-oxidants, cellular ROS levels, and inhibited procoagulant platelet formation and arterial thrombosis in aged mice. Conclusions: Platelet mitochondrial ROS contributes to age-related thrombosis and endogenous SOD2 protects from platelet-dependent thrombin generation and thrombosis during aging.
Databáze: OpenAIRE
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