Protective Effect Of Ticagrelor Research Articles

Protective Effect of Ticagrelor Against Infective Endocarditis Induced by Virulent Staphylococcus aureus in Mice

In addition to its potent antiplatelet activity, ticagrelor possesses antibacterial properties against gram-positive bacteria. We wondered whether the typical clinical dosage of ticagrelor could prevent the development of infective endocarditis caused by highly virulent Staphylococcus aureus. Ticagrelor prevented vegetation formation in a mouse model of inflammation-induced endocarditis. The dosage achieved in patients under ticagrelor therapy altered bacterial toxin production and adherence on activated endothelial cells, thereby mitigating bacterial virulence. Besides the previously described bactericidal activity at high doses, ticagrelor at typical clinical doses possesses antivirulence activity against S aureus. Ticagrelor antiplatelet activity further interferes with the interplay between platelets and bacteria.

Ticagrelor Protects against Sepsis-Induced Acute Kidney Injury through an Adenosine Receptor-Dependent Pathway.

Ticagrelor is a widely used anti-platelet drug. However, the mechanisms by which ticagrelor protects against sepsis-induced acute kidney injury (AKI) have not been clearly demonstrated. We designed this study to explore the protective effect of ticagrelor on sepsis-induced AKI and to explore the underlying mechanisms. C57BL6J mice received oral ticagrelor (20 mg/kg and 50 mg/kg) for 7 days, and then caecal ligation and puncture (CLP) were performed. An adenosine receptor antagonist, CGS15943, was administered (10 mg/kg, intraperitoneal injection) to block the adenosine pathway 2 h before CLP. After 24 h, serum creatinine levels were measured. Periodic acid-Schiff (PAS) staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining were employed to analyze pathological changes and cell apoptosis. Serum concentrations of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and mRNA expression of tissue TNF-α and IL-1β were detected. Western blotting analysis was used to determine AKT and mammalian target of rapamycin (mTOR) protein expression in the kidney. PAS staining showed less swelling of renal tubules, and TUNEL staining revealed less cell apoptosis in the ticagrelor group than in the CLP group. Serum creatinine levels were significantly lower in the ticagrelor group than in the CLP group. Moreover, significantly lower serum and kidney levels of TNF-α and IL-1β were observed in the ticagrelor group. CGS15943 blocked the effects of ticagrelor. Western blotting analysis showed increased phosphorylation of AKT and mTOR in the kidneys of the 50 mg/kg ticagrelor group. The adenosine receptor antagonist inhibited the activation of AKT and mTOR. This study demonstrates that the protective effect of ticagrelor on sepsis-induced AKI depends on adenosine receptor activation and the subsequent increase of AKT and mTOR phosphorylation.

P0521TICAGRELOR PROTECTS KIDNEY FROM SEPSIS INDUCED ACUTE KIDNEY INJURY THROUGH ADENOSINE DEPENDENT WAY

Abstract Background and Aims Sepsis induced acute kidney injury (AKI) is common in intensive care unit in multiple organ failure patients. Ticagrelor is an anti-platelet drug that widely applied in coronary artery disease. In addition, ticagrelor can increase the level of adenosine. Recent study had indicated that ticagrelor can protect renal function in sepsis induced AKI. However, the detailed mechanism was still unknown. Accordingly, we designed this trial to investigate if the ticagrelor alleviated sepsis induced AKI and demonstrated the potential mechanism that how ticagrelor works. Method C57BL6J mouse received oral ticagrelor (20mg/kg and 50mg/kg) for 7 days and caecum ligation and puncture (CLP) were performed. Adenosine-receptor antagonist was administered (10mg/kg, intraperitoneal injection) to block the adenosine pathway 2h before CLP. After 24h, serum creatinine was measured. PAS staining was used and TUNEL staining was applied to determine the pathological changes and cell apoptosis. Plasma concentrations of TNF-α and IL-1β were detected. Kidney tissue level of TNF-α and IL-1β were determined via qRT-PCR. Western blot was used to determine the expression of signal molecular in kidney. Results In ticagrelor group, PAS staining (fig. 1) showed that less swelling of renal tubules and TUNEL staining (fig. 2) showed the less cell apoptosis compared to CLP. Serum creatinine was significantly lower in ticagrelor group. Plasma TNF-α and IL-1β and kidney expression of TNF-α and IL-1β were significantly lower in ticagrelor group. Adenosine-receptor antagonist significantly blocked the effect of ticagrelor (fig. 3 ang 4). Western blot showed that ticagrelor activate the phosphorylation of AKT and mTOR in kidney. Adenosine-receptor antagonist inhibited the activation of AKT and mTOR (fig. 5). Conclusion The protective effect of ticagrelor was dependent on adenosine-receptor activation with downstream upregulation of phosphorylation of AKT and mTOR in sepsis induced AKI.

Ticagrelor for the primary prevention of stroke in patients with coronary artery disease: a systematic review and meta-analysis of randomized controlled trials.

Coronary artery disease (CAD) patients had a higher risk of first-ever stroke than general population even when they were on antiplatelet treatment. It was unknown whether more potent antiplatelet inhibitor ticagrelor which also provided adenosine-mediated protection would improve the primary stroke prevention for CAD. PubMed, Embase, Web of Science and CERNTRAL were searched for randomized clinical trials (RCTs) comparing efficacy and safety outcomes of over 30-day use of ticagrelor versus other antiplatelet drugs or placebo in patients with acute or chronic coronary syndrome. RCTs involving patients with any stroke history were excluded. Based on 5 RCTs with 45,843 patients, ticagrelor-involving regimens significantly reduced first-ever strokes (risk ratio [RR] 0.81; 95% confidential interval [CI] 0.71-0.94; I2 = 0%) in comparison to other antiplatelet regimens in CAD, where the benefits in reducing ischemic strokes (IS) (RR 0.80; 95% CI 0.68-0.94; I2 = 0%) was not canceled out by the increase of intracranial hemorrhage (ICH) (RR 1.41; 95% CI 1.05-1.89; I2 = 0%). According to results of subgroup analyses, the protective effects of ticagrelor on first-ever stroke were more significant with treatment duration of more than 1year, dosage of 60mg twice daily, and in clinical settings of chronic coronary syndrome. In conclusion, available evidence from aggregate data supported a modest advantage of ticagrelor-involving regimens for the primary stroke prevention in CAD compared with other antiplatelet regimens after the trade-off between reducing IS and inducing ICH, where more benefits might be expected from long-term and low-dose use of ticagrelor among patients with chronic coronary syndrome. Further collaborative meta-analysis of individual participant data from well-designed and statistically-powered trials would be needed to generate high quality evidence on this issue.

Investigation of the protective effect of enoxaparin and ticagrelor pretreatment against ischemia-reperfusion injury in rat lung tissue.

This study was conducted to reveal the possible protective effects of ticagrelor and enoxaparin pretreatment against ischemia-reperfusion (IR)-induced injury on the lung tissue of a rat model. Wistar albino rats were randomly divided into 4 groups as follows: group-1 (control-sham), group-2 (control-saline+IR), group-3 (ticagrelor+IR), group-4 (enoxaparin+IR). Before the ischemic period, saline, ticagrelor, and enoxaparin were administered to the 2nd-4th groups, respectively. In these groups, IR injury was induced by clamping the aorta infrarenally for 2 h, followed by 4 h of reperfusion except group-1. After the rats were euthanized, the lungs were processed for histological examinations. Paraffin sections were stained with Haematoxylin&Eosin (H&E) for light microscopic observation. Apoptosis was evaluated by caspase-3 immunoreactivity. Data were statistically analyzed using the SPSS software. In the lung sections stained with H&E, a normal histological structure was observed in group-1, whereas disorganized epithelial cells, hemorrhage, and inflammatory cell infiltration were seen in the alveolar wall in group-2. The histologic structure of the treatment groups was better than that of group-2. Caspase-3(+) apoptotic cells were noticeable in sections of group-2 and were lower in the treatment groups. In group-4, caspase-3 immunostaining was lower than in group-3. In group-2, apoptotic cells were significantly higher than in the other groups (p<0.001). Based on the histological results, we suggested that both therapies ameliorated the detrimental effects of IR. Caspase-3 immunohistochemistry results also revealed that pre-treatment with enoxaparin gave better results in an IR-induced rat injury model. In further studies, other parameters such as ROS and inflammatory gene expressions should be evaluated for accurate results.

The protective effect of ticagrelor on renal function in a mouse model of sepsis-induced acute kidney injury

Platelets are traditionally considered to be essential components of primary hemostasis. Recent investigations have revealed that platelets can be activated in patients with sepsis and are implicated in the development of sepsis and sepsis-induced-acute kidney injury (SAKI). In the present study, ticagrelor was used to induce a mouse model of SAKI by cecal ligation and puncture. It was found that ticagrelor could inhibit platelet activity, decrease the levels of interleukin-1β and serum creatinine, reduce infiltration of neutrophils in renal tissue, and attenuate cell apoptosis in the kidney. The results suggested that ticagrelor could protect renal function by inhibiting inflammation, recruitment of neutrophils into the kidney, and cell apoptosis in renal tissue. Thus, the findings might provide new strategies for preventing SAKI.

PRotective Effect on the coronary microcirculation of patients with DIabetes by Clopidogrel or Ticagrelor (PREDICT): study rationale and design. A randomized multicenter clinical trial using intracoronary multimodal physiology

BackgroundIn diabetic patients a predisposed coronary microcirculation along with a higher risk of distal particulate embolization during primary percutaneous intervention (PCI) increases the risk of peri-procedural microcirculatory damage. However, new antiplatelet agents, in particular Ticagrelor, may protect the microcirculation through its adenosine-mediated vasodilatory effects.MethodsPREDICT is an original, prospective, randomized, multicenter controlled study designed to investigate the protective effect of Ticagrelor on the microcirculation during PCI in patient with diabetes mellitus type 2 or pre-diabetic status. The primary endpoints of this study aim to test (i) the decrease in microcirculatory resistance with antiplatelet therapy (Ticagrelor > Clopidogrel; mechanistic effect) and (ii) the relative microcirculatory protection of Ticagrelor compared to Clopidogrel during PCI (Ticagrelor < Clopidogrel; protective effect).ConclusionsPREDICT will be the first multicentre clinical trial to test the adenosine-mediated vasodilatory effect of Ticagrelor on the microcirculation during PCI in diabetic patients. The results will provide important insights into the prospective beneficial effect of this drug in preventing microvascular impairment related to PCI (http://www.clinicaltrials.gov No. NCT02698618).

Protective Effects of Ticagrelor on Myocardial Injury After Infarction.

The P2Y12 receptor antagonist ticagrelor has been shown to be clinically superior to clopidogrel. Although the underlying mechanisms remain elusive, ticagrelor may exert off-target effects through adenosine-related mechanisms. We aimed to investigate whether ticagrelor reduces myocardial injury to a greater extent than clopidogrel after myocardial infarction (MI) at a similar level of platelet inhibition and to determine the underlying mechanisms. Pigs received the following before MI induction: (1) placebo-control; (2) a loading dose of clopidogrel (600 mg); (3) a loading dose of ticagrelor (180 mg); or (4) a loading dose of ticagrelor followed by an adenosine A1/A2-receptor antagonist [8-(p-sulfophenyl)theophylline, 4 mg/kg intravenous] to determine the potential contribution of adenosine in ticagrelor-related cardioprotection. Animals received the corresponding maintenance doses of the antiplatelet agents during the following 24 hours and underwent 3T-cardiac MRI analysis. Platelet inhibition was monitored by ADP-induced platelet aggregation. In the myocardium, we assessed the expression and activation of proteins known to modulate edema formation, including aquaporin-4 and AMP-activated protein kinase and its downstream effectors CD36 and endothelial nitric oxide synthase and cyclooxygenase-2 activity. Clopidogrel and ticagrelor exerted a high and consistent antiplatelet effect (68.2% and 62.2% of platelet inhibition, respectively, on challenge with 20 μmol/L ADP) that persisted up to 24 hours post-MI (P<0.05). All groups showed comparable myocardial area-at-risk and cardiac worsening after MI induction. 3T-Cardiac MRI analysis revealed that clopidogrel- and ticagrelor-treated animals had a significantly smaller extent of MI than placebo-control animals (15.7 g left ventricle and 12.0 g left ventricle versus 22.8 g left ventricle, respectively). Yet, ticagrelor reduced infarct size to a significantly greater extent than clopidogrel (further 23.5% reduction; P=0.0026), an effect supported by troponin-I assessment and histopathologic analysis (P=0.0021). Furthermore, in comparison with clopidogrel, ticagrelor significantly diminished myocardial edema by 24.5% (P=0.004), which correlated with infarct mass (r=0.73; P<0.001). 8-(p-Sulfophenyl)theophylline administration abolished the cardioprotective effects of ticagrelor over clopidogrel. At a molecular level, aquaporin-4 expression decreased and the expression and activation of AMP-activated protein kinase signaling and cyclooxygenase-2 increased in the ischemic myocardium of ticagrelor- versus clopidogrel-treated animals (P<0.05). These protein changes were not observed in those animals administered the adenosine receptor blocker 8-(p-sulfophenyl)theophylline. Ticagrelor, beyond its antiplatelet efficacy, exerts cardioprotective effects by reducing necrotic injury and edema formation via adenosine-dependent mechanisms.