IIb-IIIa Research Articles

Abstract 119: LRRC8 Complex Is An ATP Release Channel Regulating Platelet Activation And Thrombosis

Platelet shape and volume changes are early mechanical events in platelet activation proposed to contribute to arterial thrombosis. Here, we identify single-nucleotide polymorphisms (SNPs) in four leucine-rich repeat containing protein subunits (LRRC8A, B, C, and D) expressed in human platelets that are independently associated with increased mean platelet volume in human genetic studies - implicating the volume-sensing LRRC8 channel complex as regulating platelet function in humans. We show LRRC8A is required for functional LRRC8/VRAC in megakaryocytes (MKs). MK-specific LRRC8A conditional knockout mice give rise to LRRC8A-null platelets with larger mean volumes. LRRC8A-null platelets and CRISPR-edited human LRRC8A KO MKs (hiPSC MKs) have reduced agonist -stimulated P-selectin exposure, and αIIbβ3 integrin activation. LRRC8A-null platelets exhibit impaired adhesion to collagen-coated surfaces, agonist-induced platelet aggregation and ATP secretion. MK-specific LRRC8A conditional knockout mice have reduced platelet thrombus formation in laser-induced cremaster arteriolar thrombosis and prolonged occlusion times in FeCl 3 -induced carotid arterial thrombosis, compared to control mice, without affecting tail bleeding times. Mechanistically, LRRC8A mediates swelling-induced ATP release to amplify agonist-stimulated calcium influx and aggregation in platelets. Treatment of platelets with small-molecule LRRC8 channel inhibitors recapitulate the defects in LRRC8A-null platelets. These studies identify the mechanoresponsive LRRC8 channel complex as a regulator of platelet function and thrombosis - providing a proof-of-concept for a novel anti-thrombotic drug target.

Contributions of the individual domains of αIIbβ3 integrin to its extension: Insights from multiscale modeling.

The platelet integrin αIIbβ3 undergoes long-range conformational transitions between bent and extended conformations to regulate platelet aggregation during hemostasis and thrombosis. However, how exactly αIIbβ3 transitions between conformations remains largely elusive. Here, we studied how transitions across bent and extended-closed conformations of αIIbβ3 integrin are regulated by effective interactions between its functional domains. We first carried out μs-long equilibrium molecular dynamics (MD) simulations of full-length αIIbβ3 integrins in bent and intermediate conformations, the latter characterized by an extended headpiece and closed legs. Then, we built heterogeneous elastic network models, perturbed inter-domain interactions, and evaluated their relative contributions to the energy barriers between conformations. Results showed that integrin extension emerges from: (i) changes in interfaces between functional domains; (ii) allosteric coupling of the head and upper leg domains with flexible lower leg domains. Collectively, these results provide new insights into integrin conformational activation based on short- and long-range interactions between its functional domains and highlight the importance of the lower legs in the regulation of integrin allostery.

Lipoxin A4 analogue, BML-111, reduces platelet activation and protects from thrombosis

Formyl peptide receptors (FPRs) are members of seven transmembrane G protein-coupled receptors superfamily that exhibit different responses based on the nature of stimulating ligand type. FPRs have been shown to be present in platelets and regulate their function. However, the effect of formyl peptide receptor 2 (FPR2/ALX) lipid ligands on platelets has not yet been addressed. Hence, we sought to study the role of FPR2/ALX ligand and lipoxin A4 lipid analogue, BML-111, in the modulation of platelet function and thrombus formation. Immunofluorescence microscopy showed subcellular distribution and peripheral mobilisation of FPR2/ALX in stimulated platelets. This variation in distribution was further confirmed using flow cytometry. BML-111 inhibited a range of platelet activities in a dose-dependent manner in response to several platelet agonists. This included aggregation, fibrinogen binding to integrin αIIbβ3, α-granule secretion, dense granule secretion, Ca2 + mobilisation and integrin αIIbβ3-mediated outside-in signaling. The selectivity of BML-111 for FPR2/ALX was confirmed using FPR2/ALX deficient mice in flow cytometry assays. In vitro thrombus formation was also inhibited by various concentrations of BML-111. Moreover, the levels of vasodilator stimulated phosphorylation (VASP-S157) increased significantly after BML-111 treatment in resting and stimulated platelets via protein kinase A (PKA) independently of cyclic adenosine monophosphate (cAMP) signaling. Together, our findings demonstrate the significance of BML-111 as a modulator of platelet function via FPR2/ALX and unravel the thrombo-protective potentials of BML-111 induced signaling against thrombo-inflammatory diseases.

Apolipoprotein A-IV polymorphisms Q360H and T347S attenuate its endogenous inhibition of thrombosis

Platelets are small anucleate cells that play a key role in thrombosis and hemostasis. Our group previously identified apolipoprotein A-IV (apoA-IV) as an endogenous inhibitor of thrombosis by competitive blockade of the αIIbβ3 integrin on platelets. ApoA-IV inhibition of platelets was dependent on the N-terminal D5/D13 residues, and enhanced with absence of the C-terminus, suggesting it sterically hinders its N-terminal platelet binding site. The C-terminus is also the site of common apoA-IV polymorphisms apoA-IV-1a (T347S) and apoA-IV-2 (Q360H). Interestingly, both are linked with an increased risk of cardiovascular disease, however, the underlying mechanism remains unclear. Here, we generated recombinant apoA-IV and found that the Q360H or T347S polymorphisms dampened its inhibition of platelet aggregation in human platelet-rich plasma and gel-filtered platelets, reduced its inhibition of platelet spreading, and its inhibition of P-selectin on activated platelets. Using an ex vivo thrombosis assay, we found that Q360H and T347S attenuated its inhibition of thrombosis at both high (1800s−1) and low (300s−1) shear rates. We then demonstrate a conserved monomer-dimer distribution among apoA-IV WT, Q360H, and T347S and use protein structure modelling software to show Q360H and T347S enhance C-terminal steric hindrance over the N-terminal platelet-binding site. These data provide critical insight into increased cardiovascular risk for individuals with Q360H or T347S polymorphisms.

Full-length αIIbβ3 cryo-EM structure reveals intact integrin initiate-activation intrinsic architecture

Integrin αIIbβ3 is the key receptor regulating platelet retraction and accumulation and a proven drug-target for antithrombotic therapies. Here we resolve the cryo-EM structures of the full-length αIIbβ3, which covers three distinct states along the activation pathway. Firstly, we obtain the αIIbβ3 structure at 3Å resolution in the inactive state, revealing the overall topology of the heterodimer with the transmembrane (TM) helices and the ligand-binding domain tucked in a specific angle proximity to the TM region. After the addition of a Mn2+ agonist, we resolve two coexisting structures representing two new states between inactive and active state. Our structures show conformational changes of the αIIbβ3 activating trajectory and a unique twisting of the integrin legs, which is required for platelets accumulation. Our structure provides direct structural evidence for how the lower legs are involved in full-length integrin activation mechanisms and offers a new strategy to target the αIIbβ3 lower leg.

Platelet Activation Pathways Controlling Reversible Integrin αIIbβ3 Activation.

Background Agonist-induced platelet activation, with the integrin αIIbβ3 conformational change, is required for fibrinogen binding. This is considered reversible under specific conditions, allowing a second phase of platelet aggregation. The signaling pathways that differentiate between a permanent or transient activation state of platelets are poorly elucidated. Objective To explore platelet signaling mechanisms induced by the collagen receptor glycoprotein VI (GPVI) or by protease-activated receptors (PAR) for thrombin that regulate time-dependent αIIbβ3 activation. Methods Platelets were activated with collagen-related peptide (CRP, stimulating GPVI), thrombin receptor-activating peptides, or thrombin (stimulating PAR1 and/or 4). Integrin αIIbβ3 activation and P-selectin expression was assessed by two-color flow cytometry. Signaling pathway inhibitors were applied before or after agonist addition. Reversibility of platelet spreading was studied by microscopy. Results Platelet pretreatment with pharmacological inhibitors decreased GPVI- and PAR-induced integrin αIIbβ3 activation and P-selectin expression in the target order of protein kinase C (PKC) > glycogen synthase kinase 3 > β-arrestin > phosphatidylinositol-3-kinase. Posttreatment revealed secondary αIIbβ3 inactivation (not P-selectin expression), in the same order, but this reversibility was confined to CRP and PAR1 agonist. Combined inhibition of conventional and novel PKC isoforms was most effective for integrin closure. Pre- and posttreatment with ticagrelor, blocking the P2Y 12 adenosine diphosphate (ADP) receptor, enhanced αIIbβ3 inactivation. Spreading assays showed that PKC or P2Y 12 inhibition provoked a partial conversion from filopodia to a more discoid platelet shape. Conclusion PKC and autocrine ADP signaling contribute to persistent integrin αIIbβ3 activation in the order of PAR1/GPVI > PAR4 stimulation and hence to stabilized platelet aggregation. These findings are relevant for optimization of effective antiplatelet treatment.

418 The antiplatelet effects of EPA, an omega-3 fatty acid, are mediated by its 12-lipoxygenase metabolite, 12-HEPE

OBJECTIVES/GOALS: To determine whether cardioprotective effects observed in individuals taking dietary supplementation with eicosapentaenoic acid (EPA), an ω-3 polyunsaturated fatty acid, are realized by altering platelet function, and if these effects are mediated through the 12-lipoxygenase derived metabolite, 12-hydroxyeicosapentaenoic acid (12-HEPE). METHODS/STUDY POPULATION: Washed platelets or platelet rich plasma from healthy human donors were treated with EPA and 12-HEPE to assess their ability to inhibit platelet activation. Platelets were stimulated with agonists targeting different steps of the hemostatic response to vascular injury. Platelet aggregation, dense granule secretion, surface expression of integrin αIIbβ3 and P-selectin, and clot retraction were analyzed. To assess signaling through Gαs-GPCRs and protein kinase A activity, phosphorylation of vasodilator-stimulated phosphoprotein (VASP) was examined via western blot following treatment with EPA or 12-HEPE. RESULTS/ANTICIPATED RESULTS: EPA and 12-HEPE dose-dependently inhibit both collagen and thrombin-induced platelet aggregation. Furthermore, 12-HEPE more potently attenuates dense granule secretion and surface expression of platelet activation markers, integrin αIIbβ3 and P-selectin, in comparison to EPA. Plasma treated with EPA delayed thrombin-induced clot retraction, while 12-HEPE had no effect. Additionally, treatment with 12-HEPE increases phosphorylation of VASP, suggesting it could signal through the activation of the eicosanoid Gαs-GPCRs. DISCUSSION/SIGNIFICANCE: Here, we show for the first time that EPA directly inhibits platelet activation through its 12-LOX metabolite, 12-HEPE. These findings provide further insight into the mechanisms underlying the cardioprotective effects of EPA. A better understanding of current PUFA supplementations can inform treatment and prevention of cardiovascular diseases.

Impact of rise and fall phases of shear on platelet activation and aggregation using microfluidics.

Blood flow disorders are often the result of the non-physiological narrowing of blood arteries caused by atherosclerosis and thrombus. The blood then proceeds through rising-peak-decreasing phases as it passes through the narrow area. Although abnormally high shear is known to activate platelets, the shear process that platelets undergo in small arteries is complex. Thus, understanding how each shear phase affects platelet activation can be used to improve antiplatelet therapy and decrease the risk of side effects like bleeding. Blood samples were sheared (68.8 ms,5200s-1) in vitro by the microfluidic technique, and platelet activation levels (P-selectin and integrin αIIbβ3) and von Willebrand factor (vWF) binding to platelets were analyzed by flow cytometry. Post-stenosis platelet aggregation was dynamically detected using microfluidic technology. We studied TXA2, P2Y12-ADP, and integrin αIIbβ3-fibrinogen receptor pathways by adding antiplatelet drugs, such as acetylsalicylic acid (ASA, an active ingredient of aspirin that inhibits platelet metabolism), ticagrelor (hinders platelet activation), and tirofiban (blocks integrin αIIbβ3 receptor) in vitro, respectively, to determine platelet activation function mediated by transient non-physiological high shear rates. We demonstrated that platelets can be activated under transient pathological high shear rates. The shear rise and fall phases influenced shear-induced platelet activation by regulating the binding of vWF to platelets. The degree of platelet activation and aggregation increased with multiple shear rise and fall phases. ASA did not inhibit shear-mediated platelet activation, but ticagrelor and tirofiban effectively inhibited shear-mediated platelet activation. Our data demonstrated that the shear rise and fall phases play an important role in shear-mediated platelet activation and promote platelet activation and aggregation in a vWF-dependent manner. Blocking integrin αIIbβ3 receptor and hindering P2Y12-ADP were beneficial to reducing shear-mediated platelet activation.

A mouse model of the protease-activated receptor 4 Pro310Leu variant has reduced platelet reactivity

BackgroundProtease-activated receptor 4 (PAR4) mediates thrombin signaling on platelets and other cells. Our recent structural studies demonstrated that a single nucleotide polymorphism in extracellular loop 3 and PAR4-P310L (rs2227376) leads to a hyporeactive receptor. ObjectivesThe goal of this study was to determine how the hyporeactive PAR4 variant in extracellular loop 3 impacts platelet function in vivo using a novel knock-in mouse model (PAR4-322L). MethodsA point mutation was introduced into the PAR4 gene F2rl3 via CRISPR/Cas9 to create PAR4-P322L, the mouse homolog to human PAR4-P310L. Platelet response to PAR4 activation peptide (AYPGKF), thrombin, ADP, and convulxin was monitored by αIIbβ3 integrin activation and P-selectin translocation using flow cytometry or platelet aggregation. In vivo responses were determined by the tail bleeding assay and the ferric chloride–induced carotid artery injury model. ResultsPAR4-P/L and PAR4-L/L platelets had a reduced response to AYPGKF and thrombin measured by P-selectin translocation or αIIbβ3 activation. The response to ADP and convulxin was unchanged among genotypes. In addition, both PAR4-P/L and PAR4-L/L platelets showed a reduced response to thrombin in aggregation studies. There was an increase in the tail bleeding time for PAR4-L/L mice. The PAR4-P/L and PAR4-L/L mice both showed an extended time to arterial thrombosis. ConclusionPAR4-322L significantly reduced platelet responsiveness to AYPGKF and thrombin, which is in agreement with our previous structural and cell signaling studies. In addition, PAR4-322L had prolonged arterial thrombosis time. Our mouse model provides a foundation to further evaluate the role of PAR4 in other pathophysiological contexts.

First experience of endoscopic radiofrequency ablation in tumor-induced stenosis of extrahepatic bile ducts

Aim. To evaluate technical features, safety and efficiency of radiofrequency ablation in tumor strictures of extrahepatic bile ducts. Materials and methods. An ongoing prospective observational study from September 2022 to June 2023 enrolled patients with unresectable extrahepatic bile duct tumors. Examination involved esophagogastroduodenoscopy, endoscopic ultrasound, retrograde cholangiopancreatography and video choledochoscopy with biopsy. Ductalradiofrequency ablation with polymeric or self-expanding metallic stent placement was applied as the main treatment method for the first time in Russia. Results. 3 patients (75 %) were diagnosed with cholangiocarcinoma of stage IIb–IIIa, 1 patient – with mucinous cystic tumor with signs of severe intraepithelial neoplasia. Radiofrequency ablation was successfully performed in all patients: tumor stenosis was completely eliminated, no complications reported in the immediate and distant period. The median follow-up period amounted to 8 months. Conclusion. The results of the first application of ductal radiofrequency ablation in unresectable tumors of extrahepatic bile ducts with stenosis prove to be positive. The method is considered to be effective, minimally invasive and safe.

Multi-proteomic analyses of 5xFAD mice reveal new molecular signatures of early-stage Alzheimer's disease.

An early diagnosis of Alzheimer's disease is crucial as treatment efficacy is limited to the early stages. However, the current diagnostic methods are limited to mid or later stages of disease development owing to the limitations of clinical examinations and amyloid plaque imaging. Therefore, this study aimed to identify molecular signatures including blood plasma extracellular vesicle biomarker proteins associated with Alzheimer's disease to aid early-stage diagnosis. The hippocampus, cortex, and blood plasma extracellular vesicles of 3- and 6-month-old 5xFAD mice were analyzed using quantitative proteomics. Subsequent bioinformatics and biochemical analyses were performed to compare the molecular signatures between wild type and 5xFAD mice across different brain regions and age groups to elucidate disease pathology. There was a unique signature of significantly altered proteins in the hippocampal and cortical proteomes of 3- and 6-month-old mice. The plasma extracellular vesicle proteomes exhibited distinct informatic features compared with the other proteomes. Furthermore, the regulation of several canonical pathways (including phosphatidylinositol 3-kinase/protein kinase B signaling) differed between the hippocampus and cortex. Twelve potential biomarkers for the detection of early-stage Alzheimer's disease were identified and validated using plasma extracellular vesicles from stage-divided patients. Finally, integrin α-IIb, creatine kinase M-type, filamin C, glutamine γ-glutamyltransferase 2, and lysosomal α-mannosidase were selected as distinguishing biomarkers for healthy individuals and early-stage Alzheimer's disease patients using machine learning modeling with approximately 79% accuracy. Our study identified novel early-stage molecular signatures associated with the progression of Alzheimer's disease, thereby providing novel insights into its pathogenesis.

Platelet dysfunction reversal with cold-stored vs room temperature–stored platelet transfusions

AbstractPlatelets are stored at room temperature for 5 to 7 days (room temperature–stored platelets [RSPs]). Because of frequent and severe shortages, the US Food and Drug Administration recently approved up to 14-day cold-stored platelets (CSPs) in plasma. However, the posttransfusion function of CSPs is unknown and it is unclear which donors are best suited to provide either RSPs or CSPs. In this study, we sought to evaluate the posttransfusion platelet function and its predictors for platelets stored for the maximum approved storage times (7-day RSPs and 14-day CSPs) in healthy volunteers on acetylsalicylic acid (ASA). We conducted a randomized crossover study in 10 healthy humans. Individuals donated 1 platelet unit, stored at either 22°C or 4°C based on randomization. Before transfusion, participants ingested ASA to inhibit endogenous platelets. Transfusion recipients were tested for platelet function and lipid mediators. Platelet units were tested for lipid mediators only. A second round of transfusion with the alternative product was followed by an identical testing sequence. RSPs reversed platelet inhibition significantly better in αIIbβ3 integrin activation–dependent assays. In contrast, CSPs in recipients led to significantly more thrombin generation, which was independent of platelet microparticles. Lysophosphatidylcholine-O species levels predicted the procoagulant capacity of CSPs. In contrast, polyunsaturated fatty acid concentrations predicted the aggregation response of RSPs. In summary, we provide, to our knowledge, the first efficacy data of extended-stored CSPs in plasma. Our results suggest that identifying ideal RSP and CSP donors is possible, and pave the way for larger studies in the future. This trial is registered at www.ClinicalTrials.gov as #NCT0511102.

Constitutive hypercoagulability in pediatric sickle cell disease patients with hemoglobin SS genotype

BackgroundConstitutive inflammation and hemostatic activation have been identified as key contributors to the pathophysiology of sickle cell disease (SCD), leading to clinical consequences such as vaso-occlusive crises and stroke. Patients with hemoglobin SS (HbSS) and hemoglobin SC (HbSC) genotypes are reported to have different symptoms, as do patients in steady-state and crisis situations. Differences among these groups remain unclear in pediatric patients. ObjectivesTo compare hemostatic activity in HbSS and HbSC pediatric patients during steady state, in crisis, and in clinical follow-up and compare HbSS and HbSC patients with normal healthy children. MethodsWhole-blood coagulation assay thromboelastography (TEG) was used to assess hemostatic activity. In parallel, flow cytometry was used to assess procoagulant surface expression of platelets and red blood cells. ResultsTEG results indicated no significant differences in clotting onset (R time), clot maximum amplitude, or maximum rate of thrombus generation among steady-state, crisis, and follow-up subgroups of HbSS and HbSC patients. TEG parameters did not differ significantly between HbSC patients and healthy children, while HbSS patients showed significantly shorter R time and greater maximum amplitude and maximum rate of thrombus generation, all indicative of a constitutive hypercoagulable state. Flow cytometry results did not detect increased platelet integrin αIIbβ3 activation or red blood cell procoagulant surface expression in SCD patients compared with unaffected children. ConclusionOur results indicate that pediatric SCD patients with the HbSS genotype have constitutively activated hemostasis relative to HbSC patients and healthy children. It remains to be determined how treatments that improve clinical outcomes in SCD patients affect this constitutively hypercoagulable state.

Icaritin Sensitizes Thrombin- and TxA2-Induced Platelet Activation and Promotes Hemostasis via Enhancing PLCγ2-PKC Signaling Pathways.

Vascular injury results in uncontrollable hemorrhage in hemorrhagic diseases and excessive antithrombotic therapy. Safe and efficient hemostatic agents which can be orally administered are urgently needed. Platelets play indispensable roles in hemostasis, but there is no drug exerting hemostatic effects through enhancing platelet function. The regulatory effects of icaritin, a natural compound isolated from Herba Epimedii, on the dense granule release, thromboxane A2 (TxA2) synthesis, α-granule release, activation of integrin αIIbβ3, and aggregation of platelets induced by multiple agonists were investigated. The effects of icaritin on tail vein bleeding times of warfarin-treated mice were also evaluated. Furthermore, we investigated the underlying mechanisms by which icaritin exerted its pharmacological effects. Icaritin alone did not activate platelets, but significantly potentiated the dense granule release, α-granule release, activation of integrin αIIbβ3, and aggregation of platelets induced by thrombin and U46619. Icaritin also shortened tail vein bleeding times of mice treated with warfarin. In addition, phosphorylated proteome analysis, immunoblotting analysis, and pharmacological research revealed that icaritin sensitized the activation of phospholipase Cγ2 (PLCγ2)-protein kinase C (PKC) signaling pathways, which play important roles in platelet activation. Icaritin can sensitize platelet activation induced by thrombin and TxA2 through enhancing the activation of PLCγ2-PKC signaling pathways and promote hemostasis, and has potential to be developed into a novel orally deliverable therapeutic agent for hemorrhages.

Antiplatelet and Antithrombotic Activities of Lespedeza cuneata via Pharmacological Inhibition of Integrin αIIbβ3, MAPK, and PI3K/AKT Pathways and FeCl3-Induced Murine Thrombosis.

Cardiovascular diseases (CVDs) have been the major cause of mortality all around the globe. Lespedeza cuneata abbreviated as L. cuneata with the authority name of Dumont de Courset (G. Don) is a perennial flowering plant commonly grown in Asian countries such as Korea, Japan, China, and Taiwan. We aimed to investigate the L. cuneata extract's antiplatelet and antithrombotic properties as GC-MS analysis indicated that the extract contained short-chain fatty acids, which have been reported to possess beneficial cardiovascular effects. L. cuneata was extracted using water, 50% EtOH, 70% EtOH, and 100% EtOH. For in vitro antiplatelet analysis, washed platelets were prepared and incubated with L. cuneata with 200 μg/mL of 50% EtOH in the presence of 1 mM of CaCl2 for 1 minute followed by agonist (collagen 2.5 μg/mL or ADP 10 μM or thrombin 0.1 U/mL) stimulation for 5 minutes over light transmission aggregometer. Scanning electron microscopy was performed to assess platelet shape change. ATP release and intracellular calcium mobilization were quantified to assess the granular content. Fibrinogen-binding assay and clot retraction assay assessed integrin αIIbβ3-mediated inside-out and outside-in signaling. Protein phosphorylation expression was investigated by western blot analysis. Finally, the in vivo antithrombotic efficacy was investigated by oral dosage of L. cuneata 200 and 400 mg/kg and aspirin 100 mg/kg for 7 days, and tail bleeding and FeCl3-induced murine thrombus model were performed. In vitro platelet aggregation and platelet shape change were dose-dependently suppressed by L. cuneata. Calcium mobilization, dense granules secretion, integrin αIIbβ3-mediated inside-out and outside-in signaling, and protein phosphorylation of MAPK and PI3K/Akt pathways were significantly inhibited. In vivo assays revealed that L. cuneata prevents side effects of synthetic drugs via nonsignificantly increasing bleeding time and improving coronary artery blood flow and animal survival. Our results demonstrate that L. cuneata exhibited potent antiplatelet and antithrombotic effects and can be considered a potential herbal medicine with cardioprotective effects.

Force-regulated conformational changes of αIIBβ3 and αVβ3 integrins: Insights from equilibrium and enhanced molecular dynamics simulations

Force-regulated conformational changes of αIIBβ3 and αVβ3 integrins: Insights from equilibrium and enhanced molecular dynamics simulations

Radiochemotherapy and interstitial brachytherapy for cervical cancer: clinical results and patient-reported outcome measures

ObjectiveTo evaluate clinical results and long-term patient-reported outcome measures (PROMs) on quality of life in cervical cancer patients following radiochemotherapy (RCT) and brachytherapy (BT) as definitive treatment.Materials and methodsBetween 2003 and 2023, a total of 132 patients with advanced cervical cancer were evaluated for possible treatment. Patients treated by postoperative RCT, palliative radiotherapy, and those treated for recurrent disease were excluded. Thus, 46 patients receiving standard RCT and BT as their curative treatment were included in this study. PROMs were assessed prospectively by patients’ self-completion of the EORTC-QLQ-C30 and EORTC-QLQ-CX24 questionnaires.ResultsFive-year overall survival (OS), distant metastases-free survival (DMFS), and pelvic tumor-free survival rates (PTFS) were 53%, 54%, and 83%, respectively. A significant impact on OS was seen for FIGO (International Federation of Gynecologic Oncology) stage (IIB–IIIA: 79% vs. IIIB–IVA: 33%, p = 0.015), for overall treatment time (OTT; 50–65 d: 64% vs. > 65 d: 38%, p = 0.004), and for rectal D2cc (≤ 73 Gy: 50% vs. > 73 Gy: 38%, p = 0.046). The identical parameters were significantly associated with DMFS (FIGO stage: p = 0.012, OTT: p = 0.008, D2cc: p = 0.024). No parameters with a significant influence on PTFS were seen. In multivariate analysis, an impact of FIGO stage on OS (p = 0.05) and DMFS (p = 0.014) was detected, and of rectal D2cc on DMFS (p = 0.031). The overall QoL score was 63/100. Cognitive function was the least impaired (84/100), while role functioning was the worst (67/100). On the symptom scale, insomnia (46/100), fatigue (41/100), dyspnea (32/100), pain (26/100), and financial difficulties (25/100) were scored the worst. According to EORTC-QLQ-CX24, peripheral neuropathy (36/100) and lymphedema (32/100) occurred most frequently. Impaired sexual/vaginal functioning (32/100) and body image (22/100) were also frequently recorded.ConclusionIn patients with advanced cervical cancer, a combination of RCT and BT remains an excellent treatment option. In terms of patient-reported long-term quality of life, specific support is needed to alleviate symptoms including lymphedema, peripheral neuropathy, and impaired sexual activity.

Microbubble Biointerfacing by Regulation of the Platelet Membrane Surfactant Activity at the Gas‐Liquid Interface for Acute Thrombosis Targeting

AbstractBiointerfacing nanomaterials with cell membranes has been successful in the functionalization of nanoparticles or nanovesicles, but microbubble functionalization remains challenging due to the unique conformation of the lipid monolayer structure at the gas‐liquid interface that provides insufficient surfactant activity. Here, we describe a strategy to rationally regulate the surfactant activity of platelet membrane vesicles by adjusting the ratio of proteins to lipids through fusion with synthetic phospholipids (i.e., liposomes). A “platesome” with the optimized protein‐to‐lipid ratio can be assembled at the gas‐liquid interface in the same manner as pulmonary surfactants to stabilize a microsized gas bubble. Platesome microbubbles (PMBs) inherited 61.4 % of the platelet membrane vesicle proteins and maintained the active conformation of integrin αIIbβ3 without the talin 1 for fibrin binding. We demonstrated that the PMBs had good stability, long circulation, and superior functionality both in vitro and in vivo. Moreover, by molecular ultrasound imaging, the PMBs provide up to 11.8 dB of ultrasound signal‐to‐noise ratio enhancement for discriminating between acute and chronic thrombi. This surface tension regulating strategy may provide a paradigm for biointerfacing microbubbles with cell membranes, offering a potential new approach for the construction of molecular ultrasound contrast agents for the diagnosis of different diseases.

Microbubble Biointerfacing by Regulation of the Platelet Membrane Surfactant Activity at the Gas-Liquid Interface for Acute Thrombosis Targeting.

Biointerfacing nanomaterials with cell membranes has been successful in the functionalization of nanoparticles or nanovesicles, but microbubble functionalization remains challenging due to the unique conformation of the lipid monolayer structure at the gas-liquid interface that provides insufficient surfactant activity. Here, we describe a strategy to rationally regulate the surfactant activity of platelet membrane vesicles by adjusting the ratio of proteins to lipids through fusion with synthetic phospholipids (i.e., liposomes). A "platesome" with the optimized protein-to-lipid ratio can be assembled at the gas-liquid interface in the same manner as pulmonary surfactants to stabilize a microsized gas bubble. Platesome microbubbles (PMBs) inherited 61.4 % of the platelet membrane vesicle proteins and maintained the active conformation of integrin αIIbβ3 without the talin 1 for fibrin binding. We demonstrated that the PMBs had good stability, long circulation, and superior functionality both in vitro and in vivo. Moreover, by molecular ultrasound imaging, the PMBs provide up to 11.8 dB of ultrasound signal-to-noise ratio enhancement for discriminating between acute and chronic thrombi. This surface tension regulating strategy may provide a paradigm for biointerfacing microbubbles with cell membranes, offering a potential new approach for the construction of molecular ultrasound contrast agents for the diagnosis of different diseases.

Inhibition of mitochondrial calcium transporters alters adp-induced platelet responses.

ADP-stimulated elevation of cytosolic Ca2+ is an important effector mechanism for platelet activation. The rapidly elevating cytosolic Ca2+ is also transported to mitochondrial matrix via Mitochondrial Ca2+ Uniporter (MCU) and extruded via Na+/Ca2+/Li+ Exchanger (NCLX). However, the exact contribution of MCU and NCLX in ADP-mediated platelet responses remains incompletely understood. The present study aimed to elucidate the role of mitochondrial Ca2+ transport in ADP-stimulated platelet responses by inhibition of MCU and NCLX with mitoxantrone (MTX) and CGP37157 (CGP), respectively. As these inhibitory strategies are reported to cause distinct effects on matrix Ca2+ concentration, we hypothesized to observe opposite impact of MTX and CGP on ADP-induced platelet responses. Platelet aggregation profiling was performed by microplate-based spectrophotometery while p-selectin externalization and integrin αIIbβ3 activation were analyzed by fluorescent immunolabeling using flow cytometery. Our results confirmed the expression of both MCU and NCLX mRNAs with relatively low abundance of NCLX in human platelets. In line with our hypothesis, MTX caused a dose-dependent inhibition of ADP-induced platelet aggregation without displaying any cytotoxicity. Likewise, ADP-induced p-selectin externalization and integrin αIIbβ3 activation was also significantly attenuated in MTX-treated platelets. Concordantly, inhibition of NCLX with CGP yielded an accelerated ADP-stimulated platelet aggregation which was associated with an elevation of p-selectin surface expression and αIIbβ3 activation. Together, these findings uncover a vital and hitherto poorly characterized role of mitochondrial Ca2+ transporters in ADP-induced platelet activation.