Loss of Sirt3 accelerates arterial thrombosis by increasing formation of neutrophil extracellular traps and plasma tissue factor activity

Abstract

AimsSirtuin 3 (Sirt3) is a mitochondrial, nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase that reduces oxidative stress by activation of superoxide dismutase 2 (SOD2). Oxidative stress enhances arterial thrombosis. This study investigated the effects of genetic Sirt3 deletion on arterial thrombosis in mice in an inflammatory setting and assessed the clinical relevance of these findings in patients with ST-elevation myocardial infarction (STEMI).Methods and resultsUsing a laser-induced carotid thrombosis model with lipopolysaccharide (LPS) challenge, in vivo time to thrombotic occlusion in Sirt3−/− mice (n = 6) was reduced by half compared to Sirt3+/+ wild-type (n = 8, P < 0.01) controls. Ex vivo analyses of whole blood using rotational thromboelastometry revealed accelerated clot formation and increased clot stability in Sirt3−/− compared to wild-type blood. rotational thromboelastometry of cell-depleted plasma showed accelerated clotting initiation in Sirt3−/− mice, whereas overall clot formation and firmness remained unaffected. Ex vivo LPS-induced neutrophil extracellular trap formation was increased in Sirt3−/− bone marrow-derived neutrophils. Plasma tissue factor (TF) levels and activity were elevated in Sirt3−/− mice, whereas plasma levels of other coagulation factors and TF expression in arterial walls remained unchanged. SOD2 expression in bone marrow -derived Sirt3−/− neutrophils was reduced. In STEMI patients, transcriptional levels of Sirt3 and its target SOD2 were lower in CD14+ leukocytes compared with healthy donors (n = 10 each, P < 0.01).Conclusions Sirt3 loss-of-function enhances experimental thrombosis in vivo via an increase of neutrophil extracellular traps and elevation of TF suggesting thrombo-protective effects of endogenous Sirt3. Acute coronary thrombosis in STEMI patients is associated with lower expression levels of SIRT3 and SOD2 in CD14+ leukocytes. Therefore, enhancing SIRT3 activity by pan-sirtuin activating NAD+-boosters may provide a novel therapeutic target to prevent or treat thrombotic arterial occlusion in myocardial infarction or stroke.

Indoxyl Sulfate Promotes Arterial Thrombosis in Rat Model via Increased Levels of Complex TF/VII, PAI-1, Platelet Activation as Well as Decreased Contents of SIRT1 and SIRT3

“…However, some studies also show that sirtuins, especially Sirt1 and Sirt3, are involved in thromboprotection. The authors not only correlated the loss of sirtuins with the promotion of arterial thrombosis, but also demonstrated that their inhibition is linked to an elevated level of TF ( Breitenstein et al, 2011 ; Gaul et al, 2018 ). In addition, Gaul et al (2018) reported that arterial thrombosis in mice with Sirt3 knockout is enhanced with an increased formation of NETs.…”

“… Breitenstein et al (2011) showed that the inhibition of Sirt1 contributes to arterial thrombosis associated with the increased activation of nuclear factor-kappa B/p65, leading to augmented TF activity. Similarly, Gaul et al (2018) noticed that genetic loss of Sirtuin 3 results not only in enhanced TF activity, but also increases the formation of NETs that together lead to the promotion of arterial thrombosis. Little is known about the impact of IS on sirtuins.…”

Tissue factor at the crossroad of coagulation and cell signaling

“…Coagulation abnormalities in Pon 2‐deficient mice are indicated by shortened clotting times in vitro , likely reflecting pre‐activated coagulation factors, and are reversed by restoration of PON2 expression in endothelial cells . Deficiency of sirtuin 3 (Sirt3), another anti‐oxidative molecule inactivating superoxide dismutase 2 (SOD2), increases myeloid cell TF prothrombotic function in experimental murine thrombosis in vivo in the context of inflammation induced by endotoxin . The previously underappreciated expression of TF by endothelial cells plays a major role in sickle cell disease (SCD) pathology.…”

Interleukin-1β Mediates Arterial Thrombus Formation via NET-Associated Tissue Factor

“…As previously described [21], mice received 5 mg/kg lipopolysaccharide (LPS) (E. coli O111: B4, Sigma-Aldrich, St. Louis, MO, USA) by intraperitoneal (i.p.) injection 10 h before the laser-induced arterial thrombosis to trigger inflammation.…”

“…Murine thrombosis experiments sought to mimic an underlying inflammatory condition by administering LPS, as done previously [21]. Next, animals received the canakinumab-surrogate antibody (01BSUR, 10 µg/g) and underwent the thrombosis protocol (Figure 2A).…”