This study aimed to explore the ameliorating effects of the platelet surface glycoprotein (GP) IIb/IIIa receptor antagonist tirofiban on coagulation and fibrinolytic abnormalities in a mouse model of antibody-mediated transfusion-associated acute lung injury (ALI). This is important since ALI is a major cause of death attributable to the occurrence of adverse transfusion reactions. No information on a definite diagnosis or pathological mechanism exists, and targeted treatment options are not available. In this study, wild-type male Balb/c mice aged 8-10 weeks were randomly divided into the TRALI model, blank control, tirofiban intervention, and isotype control groups. After different treatment exposures, the mice were observed for 2 h before being sacrificed, and lung tissue samples were collected. To explore the intervention effect of tirofiban, the degree of lung injury was quantified by estimating the lung wet/dry ratio, rectal temperature, survival rate, total protein, myeloperoxidase, and via hematoxylin and eosin staining. Furthermore, the coagulation, anticoagulation, and fibrinolysis assays was measured by automatic coagulation instrument and Elisa kits, and the fluorescence densities of platelets and fibrin were quantified using immunofluorescence to analyze the effects of tirofiban on the platelet and fibrin interactions of TRALI. Compared to the TRALI model group, the lung injury indices in the tirofiban intervention group decreased significantly, and survival rates also improved. Furthermore, the level of coagulation and fibrinolytic abnormalities were obviously lower than compared to the TRALI model group. In conclusion, our findings suggest that tirofiban might interfere with TRALI by inhibiting platelet activation and improving coagulation and fibrinolytic abnormalities.

The glycoprotein (GP) IIb/IIIa receptor is found integrin present in platelet aggregations. GP IIb/IIIa antagonists interfere with platelet cross-linking and platelet-derived thrombus formation through the competition with fibrinogen and von Willebrand factor. Currently, three parenteral GP IIb/IIIa competitors (tirofiban, eptifibatide, and abciximab) are approved for clinical use in patients affected by percutaneous coronary interventions (PCI) in the location of acute coronary syndrome (ACS). GP IIb/IIIa antagonists have their mechanism of action in platelet aggregation prevention, distal thromboembolism, and thrombus formation, whereas the initial platelet binding to damage vascular areas is preserved. This work is aimed to provide a comprehensive review of the significance of GP IIb/IIIa inhibitors as a sort of antiplatelet agent. Their mechanism of action is based on factors that affect their efficacy. On the other hand, drugs that inhibit GP IIb/IIIa already approved by the FDA were reviewed in detail. Results from major clinical trials and regulatory practices and guidelines to deal with GP IIb/IIIa inhibitors were deeply investigated. The cardiovascular pathology and neuro-interventional surgical application of GP IIb/IIIa inhibitors as a class of antiplatelet agents were developed in detail. The therapeutic risk/benefit balance of currently available GP IIb/IIa receptor antagonists is not yet well elucidated in patients with ACS who are not clinically evaluated regularly for early cardiovascular revascularization. On the other hand, in patients who have benefited from PCI, the antiplatelet therapy intensification by the addition of a GP IIb/IIIa receptor antagonist (intravenously) may be an appropriate therapeutic strategy in reducing the occurrence of risks of thrombotic complications related to the intervention. Development of GP IIb/IIIa inhibitors with oral administration has the potential to include short-term antiplatelet benefits compared with intravenous GP IIb/IIIa inhibitors for long-term secondary preventive therapy in cardiovascular disease. But studies showed that long-term oral administration of GP IIb/IIIa receptor inhibitors has been ineffective in preventing ischemic events. Paradoxically, they have been linked to a high risk of side effects by producing prothrombotic and pro-inflammatory events.

During long-term antiplatelet agents (APAs) administration, patients with thrombotic diseases take a fairly high risk of life-threatening bleeding, especially when in need of urgent surgery. Rapid functional reversal of APAs remains an issue yet to be efficiently resolved by far due to the lack of any specific reversal agent in the clinic, which greatly restricts the use of APAs. Although platelet transfusion has become a common practice to counteract the function of APAs, personalized dosage of platelet transfusion is difficult to be judged by assessing the trade-off between its effectiveness and additional thrombotic risk. Here we reported a platelet-mimicking perfluorocarbon-based nanosponge, which potently reversed the antiplatelet effect of APAs by competitively binding with APAs. Platelet-mimicking perfluorocarbon-based nanosponges showed high binding affinity comparable to fresh platelets in vitro with first-line APAs, ticagrelor and tirofiban, and efficiently reversed their function in both tail bleeding and postischemic-reperfusion models. Moreover, the deficiency of platelet intrinsic thrombotic activity diminished the risk of thrombogenesis. In summary, our results demonstrated the safety and effectiveness of the platelet-mimicking nanosponge in ameliorating the bleeding risk of different APAs, which offers a promising strategy for the management of bleeding complications induced by antiplatelet therapy.

Integrins are considered the main cell-adhesion transmembrane receptors that play multifaceted roles as extracellular matrix (ECM)-cytoskeletal linkers and transducers in biochemical and mechanical signals between cells and their environment in a wide range of states in health and diseases. Integrin functions are dependable on a delicate balance between active and inactive status via multiple mechanisms, including protein-protein interactions, conformational changes, and trafficking. Due to their exposure on the cell surface and sensitivity to the molecular blockade, integrins have been investigated as pharmacological targets for nearly 40 years, but given the complexity of integrins and sometimes opposite characteristics, targeting integrin therapeutics has been a challenge. To date, only seven drugs targeting integrins have been successfully marketed, including abciximab, eptifibatide, tirofiban, natalizumab, vedolizumab, lifitegrast, and carotegrast. Currently, there are approximately 90 kinds of integrin-based therapeutic drugs or imaging agents in clinical studies, including small molecules, antibodies, synthetic mimic peptides, antibody-drug conjugates (ADCs), chimeric antigen receptor (CAR) T-cell therapy, imaging agents, etc. A serious lesson from past integrin drug discovery and research efforts is that successes rely on both a deep understanding of integrin-regulatory mechanisms and unmet clinical needs. Herein, we provide a systematic and complete review of all integrin family members and integrin-mediated downstream signal transduction to highlight ongoing efforts to develop new therapies/diagnoses from bench to clinic. In addition, we further discuss the trend of drug development, how to improve the success rate of clinical trials targeting integrin therapies, and the key points for clinical research, basic research, and translational research.

Endovascular thrombectomy (EVT) is associated with good clinical outcomes in patients with ischemic stroke, but the impact of EVT on clinical outcomes in patients with ischemic stroke with and without atrial fibrillation (AF), and the effect of adjunctive pharmacological therapies with EVT, remains unclear.

The purpose of this study was to assess the efficacy and safety of the combination of tirofiban with intravenous thrombolysis (IVT) in treating patients with capsular warning syndrome (CWS) who failed to respond to the treatment of intravenous thrombolysis alone. Tirofiban was approved for the treatment of CWS patients with fluctuating symptoms or no substantial improvement after intravenous thrombolysis within 24 h in our hospital from October 2019 to June 2021. Patients were evaluated with the National Institutes of Health Stroke Scale (NIHSS) at admission, at 72 h post-thrombolysis, at 1-week, and at 3-months with the modified Rankin Scales (MRS) score. A total of 12 patients received tirofiban and eight patients received control treatment with a history of CWS in our cohort. Among the patients, 13 patients smoked more than one pack of cigarettes a day, 17 had hypertension, 17 had hypercholesterolemia, 7 had diabetes, 1 had the history of cerebral infarction, 2 had atrial fibrillation, 7 had mild big vascular stenosis, 13 had lesions of the perforating branch by imaging, and 19 had acute capsular infarction. In both the tirofiban and control groups, NIHSS scores were significantly reduced after intravenous thrombolysis or 1-week after onset compared with before intravenous thrombolysis (P < 0.001). Before and after intravenous thrombolysis, there were no differences between the tirofiban group and control group (P = 0.970, P = 0.384, respectively). The tirofiban group, however, showed remarkably lower scores in both 1-week NIHSS and 3-month MRS than the control (P = 0.012, P = 0.003, respectively). Our study revealed that tirofiban did not increase the risk of hemorrhage and had favorable clinical efficacy as a remedial treatment for CWS patients with poor prognosis for intravenous thrombolysis, therefore indicating great potential for broader use.

Tirofiban has recently shown encouraging efficacy and safety among acute ischemic stroke (AIS) patients with mechanical thrombectomy (MT). However, the benefits of tirofiban varied among studies depending on the patient's condition, which was often not well analyzed. This study aimed to identify the characteristics of patients who may obtain the largest benefits from tirofiban. The efficacy endpoint was a favorable outcome defined as a modified Rankin Scale (mRS) score of 0~2 at 90 days. The safety endpoints were intracranial hemorrhage (ICH), symptomatic intracranial hemorrhage (sICH) and mortality at 90 days. Adjusted logistic regression analysis and subgroup analyses were utilized to investigate the factors associated with tirofiban and the outcome. All of 285 patients fit the inclusion criteria. Tirofiban was associated with a higher rate of favorable outcome (aOR 2.033, 95% CI, 1.002~4.123, p = 0.043) but not with an increased risk of ICH, sICH or mortality (p > 0.05). Moreover, subgroup analyses revealed that tirofiban was associated with favorable outcomes in patients with NIHSS > 14 (aOR 2.778, 95% CI 1.056~7.356, p = 0.038) but not in patients with NIHSS ≤ 14 (aOR 1.719, 95% CI 0.646~4.578, p = 0.278). No significant heterogeneity was found in the effect of tirofiban across the subgroups of age, sex, ASPECTS, time from onset to puncture, use of t-PA or stroke etiology (p for interaction > 0.05). The administration of tirofiban was associated with favorable outcomes in severe ischemic stroke patients, and further studies are needed to confirm this finding.

Severe acute respiratory syndrome‑coronavirus‑2 (SARS‑CoV‑2), responsible for COVID-19, is mainly a respiratory illness, but it can affect other organs also such as heart, kidneys, and liver. Myocardial injury from COVID-19 has been reported in hospitalized patients ranging from pericarditis and myocarditis to acute coronary syndrome (ACS). COVID-19 is highly hypercoagulable state and is associated with both central and peripheral thromboembolism. COVID 19 patients with ACS may not present with classical features of chest pain and electrocardiogram (ECG) is the most important initial investigation in these patients to assess for any ST or T waves changes. COVID-19 patients with cardiac involvement are the most vulnerable group of patients and have increased morbidity and mortality risk. COVID-19 infections can affect the cardiovascular system in patients with or without history of coronary artery disease (CAD), but the risk of type 1 or 2 myocardial infarction (MI), myocardial injury, ST segment elevation, myocarditis, heart failure, cardiogenic shock, and life threatening arrhythmias are more common in the former group. We present a case of 55-year-old patient who presented to our cardiac center with ST elevated myocardial infarction and high blood sugar level. Patient was recently diagnosed with type 2 diabetes mellitus (T2DM) but was not commenced on medications. Echocardiogram showed mildly impaired left ventricular systolic function (LVSF) with inferior wall hypokinesia, and ECG showed inferior leads ST elevation. Coronary angiogram showed severe mid-vessel lesion and occluded posterior left ventricular branch (PLV). Multiple attempts at aspirating the thrombus resulted in thrombolysis in MI grade 2 (TIMI 2) flow in the vessel and patient was commenced on a tirofiban infusion for 72 hours.

Platelets and their progenitors express high levels of integrin αIIbβ3, which plays a key role in platelet functions, hemostasis, and arterial thrombosis. Because of their quick and high efficacy, the three anti-αIIbβ3 drugs, abciximab, eptifibatide, and tirofiban, are regarded as potent anti-thrombotics and clinically approved by US Food and Drug Administration. However, because they interfere with the inside-out signaling of αⅡbβ3, which is required for stable platelet adhesion and aggregation, the application of abciximab, eptifibatide, and tirofiban is restricted to patients undergoing percutaneous coronary intervention. On the other hand, the outside-in signaling of αⅡbβ3 in platelets appears to be responsible for thrombus stabilization, and selective interference with the propagation of outside-in signals might signify a new therapeutic strategy to preferentially inhibit platelet-rich arterial thrombosis with less bleeding issues caused by way of compromised major hemostasis. The purpose of this review is to describe the bidirectional signal transduction of integrin αIIbβ3 in platelets with a focus on outside-in signaling, more efficient and safer anti-αⅡbβ3 peptides, and the potential drug targets for future anti-platelet research.