Study on Platelet Adhesion and Aggregation Induced by Gradient Shear Stress Using Microfluidic Chip Technology / 中国实验血液学杂志

OBJECTIVE@#To study the effect of gradient shear stress on platelet aggregation by microfluidic chip Technology.@*METHODS@#Microfluidic chip was used to simulate 80% fixed stenotic microchannel, and the hydrodynamic behavior of the stenotic microchannel model was analyzed by the finite element analysis module of sollidwork software. Microfluidic chip was used to analyze the adhesion and aggregation behavior of platelets in patients with different diseases, and flow cytometry was used to detect expression of the platelet activation marker CD62p. Aspirin, Tirofiban and protocatechuic acid were used to treat the blood, and the adhesion and aggregation of platelets were observed by fluorescence microscope.@*RESULTS@#The gradient fluid shear rate produced by the stenosis model of microfluidic chip could induce platelet aggregation, and the degree of platelet adhesion and aggregation increased with the increase of shear rate within a certain range of shear rate. The effect of platelet aggregation in patients with arterial thrombotic diseases were significantly higher than normal group (P<0.05), and the effect of platelet aggregation in patients with myelodysplastic disease was lower than normal group (P<0.05).@*CONCLUSION@#The microfluidic chip analysis technology can accurately analyze and evaluate the platelet adhesion and aggregation effects of various thrombotic diseases unde the environment of the shear rate, and is helpful for auxiliary diagnosis of clinical thrombotic diseases.

Regulation of Mitochondria on Platelet Apoptosis and Activation / 中国实验血液学杂志

OBJECTIVE@#To explore the regulation of mitochondria on platelet apoptosis and activation, and the relationship between platelet apoptosis and activation.@*METHODS@#Platelets were isolated from peripheral venous blood of healthy volunteers. Cyclosporin A (CsA), which has a protective effect on the function of platelet mitochondria, BAPTA, which can chelate calcium ions across membranes in platelets, and NAC, an antioxidant that reduces the level of intracellular reactive oxygen species, were selected for coincubation with washed platelets, respectively. By flow cytometry, platelet aggregator was used to detect the changes of platelet mitochondrial function and platelet activation indexes after different interventions.@*RESULTS@#H89, staurosporine, and A23187 led to platelet mitochondrial abnormalities, while CsA could effectively reverse the decline of platelet mitochondrial membrane potential caused by them. Antioxidant NAC could reverse platelet mitochondrial damage correspondingly, and completely reverse platelet shrinkage and phosphatidylserine eversion induced by H89. BAPTA, prostaglandin E1, acetylsalicylic acid and other inhibitors could not reverse the decline of platelet mitochondrial membrane potential.@*CONCLUSION@#Mitochondrial function plays an important role in platelet apoptosis and activation. Abnormal mitochondrial function causes the imbalance of reduction/oxidation state in platelets, which leads to platelet apoptosis. Platelet apoptosis and activation are independent signal processes.

Immature Platelet Fraction and Thrombin Generation: Preeclampsia Biomarkers / Fração de plaquetas imaturas e geração de trombina: Biomarcadores da pré-eclâmpsia

Abstract Preeclampsia, a human pregnancy syndrome, is characterized by elevated blood pressure and proteinuria after the 20th week of gestation. Its etiology remains unknown, and its pathophysiological mechanisms are related to placental hypoperfusion, endothelial dysfunction, inflammation, and coagulation cascade activation. Recently, the role of the complement system has been considered. This syndrome is one of the main causes of maternal and fetal mortality and morbidity. This article discusses the hypothesis of preeclampsia being triggered by the occurrence of inadequate implantation of the syncytiotrophoblast, associated with bleeding during the first stage of pregnancy and with augmented thrombin generation. Thrombin activates platelets, increasing the release of antiangiogenic factors and activating the complement system, inducing the membrane attack complex (C5b9). Immature platelet fraction and thrombin generation may be possible blood biomarkers to help the early diagnosis of preeclampsia.

Resumo A pré-eclâmpsia, uma síndrome da gestação humana, é caracterizada por elevação da pressão arterial e proteinúria patológica após a 20ª semana de gestação. Sua etiologia permanece desconhecida, e seus mecanismos fisiopatológicos estão relacionados à hipoperfusão placentária, disfunção endotelial, inflamação, e ativação da cascata de coagulação. Recentemente, o papel do sistema do complemento foi considerado. Essa síndrome é uma das principais causas de morbidade e mortalidade materna e fetal. Este artigo discute a hipótese de a pré-eclâmpsia ser desencadeada pela ocorrência da implantação inadequada do sinciciotrofoblasto, associada ao sangramento durante o primeiro trimestre da gravidez com aumento da geração de trombina. A trombina ativa plaquetas, aumentando a liberação de fatores antiangiogênicos na circulação e ativando o sistema do complemento, especialmente o complexo de ataque de membrana (C5b9). Portanto, a fração de plaquetas imaturas e a geração de trombina podem ser possíveis biomarcadores sanguíneos para auxílio no diagnóstico precoce da pré-eclâmpsia.

Application and Prospect of Platelet Multi-Omics Technology in Study of Blood Stasis Syndrome / 中国结合医学杂志

The abnormality of platelet function plays an important role in the pathogenesis and evolution of blood stasis syndrome (BSS). The explanation of its mechanism is a key scientific issue in the study of cardiovascular and cerebrovascular diseases and treatment. System biology technology provides a good technical platform for further development of platelet multi-omics, which is conducive to the scientific interpretation of the biological mechanism of BSS. The article summarized the pathogenesis of platelets in BSS, the mechanism of action of blood activating and stasis resolving drugs, and the application of genomics, proteomics, and metabonomics in platelet research, and put forward the concept of "plateletomics in BSS". Through the combination and cross-validation of multi-omics technology, it mainly focuses on the clinical and basic research of cardiovascular and cerebrovascular diseases; through the interactive verification of multi-omics technology and system biology, it mainly focuses on the platelet function and secretion system. The article systematically explains the molecular biological mechanism of platelet activation, aggregation, release, and other stages in the formation and development of BSS, and provides a new research idea and method for clarifying the pathogenesis of BSS and the mechanism of action of blood activating and stasis resolving drugs.

Analysis of Differential Proteins Related to Platelet Activation in Patients with Essential Thrombocythemia Based on Label-Free Quantitative Technology / 中国实验血液学杂志

OBJECTIVE@#To analysis the specific protein markers of essential thrombocythemia (ET) based on proteomics technology, to explore and verify the differential protein related to platelet activation.@*METHODS@#Blood samples were obtained from ET patients and healthy people and a certain protein mass spectrometry was detected using label-free quantitative technology. The proteins relative abundance increased or down-regulated by 1.3 times in the disease group compared with the control group, and the protein abundance in the two groups t test P＜0.05 were defined as differential proteins. Bioinformatics analysis of the differential proteins was performed using GO and KEGG. The difference in the average protein abundance between the two groups was analyzed by t test and P＜0.05 was considered statistically significant. Differential proteins were selected for verification by parallel reaction monitoring (PRM) technology.@*RESULTS@#A total of 140 differential proteins were found, of which 72 were up-regulated and 68 were down-regulated. KEGG enrichment showed that the differential protein expression was related to the platelet activation pathway. The differential proteins related to platelet activation were GPV, COL1A2, GP1bα, COL1A1 and GPVI. Among them, the expressions of GPV, GP1bα and GPVI were up-regulated, and the expressions of COL1A2 and COL1A1 were down-regulated. PRM verification of COL1A1, GP1bα, GPVI and GPV was consistent with LFP proteomics testing.@*CONCLUSION@#Differential proteins in ET patients are related to platelet activation pathway activation.Differential proteins such as GPV, GPVI, COL1A1 and GP1bα can be used as new targets related to ET platelet activation.

Recurrent pterygium resection associated to fibrin membrane graft: report of two cases / Resseção do pterígio recorrente associada ao enxerto de membrana fibrina: relato de dois casos

ABSTRACT We propose a novel surgical technique in cases of aggressive recurrent pterygium non-subsidiary of treatment with conjunctival autografts or antimetabolites. Two presented cases were treated with surgical excision and a sutured plasma rich in growth factors membrane (mPRGF) followed by rich in growth factors (PRGF) eye drops treatment. After surgery, dexamethasone, tobramycin and PRGF eye drops were prescribed for 6 weeks. After a 12-month and 3-year post-surgical follow-up respectively, treated eyes with mPRGF did not present relapse, and visual acuity improved in both cases. No ocular complications, pain, eye discomfort nor other symptoms were observed. The combined use of PRGF eye drops and mPRGF seems an effective and safe therapy for recurrent pterygium.

RESUMO Nós propomos uma nova técnica cirúrgica em casos de pterígio agressivo recorrente não subsidiário de tratamento com autoenxertos conjuntivais ou antimetabólitos. Dois casos foram tratados com excisão cirúrgica e um plasma suturado rico em membrana de fatores de crescimento (mPRGF), seguido de tratamento com colírios ricos em fatores de crescimento (PRGF). Após a cirurgia, foram prescritos colírios de dexametasona, tobramicina e PRGF por 6 semanas. Após 12 meses e 3 anos de acompanhamento pós-cirúrgico respectivamente, os olhos tratados com mPRGF não apresentaram recidiva e a acuidade visual melhorou nos dois casos. Não foram observadas complicações oculares, dor, desconforto ocular ou outros sintomas. O uso combinado de colírios de PRGF e mPRGF parece uma terapia eficaz e segura para o pterígio recorrente.

Activated platelets in central venous catheters: a flow cytometry and numerical simulation approach

The central venous catheter that is inserted in patients undergoing hemodialysis can cause hemodynamic instability and trigger complications such as thrombus formation. The objective of this study was to investigate hemostatic and numerical influences on thrombus formation in patients undergoing hemodialysis with a central venous catheter. Participants were assigned to three groups: I: clinical and laboratorial healthy individuals matched by sex and age (controls); II: participants after one month of insertion of the catheter and III: participants after 4 months of insertion of the catheter. Platelet activation was investigated by GPIIb/IIIa and p-selectin expressions using flow cytometry. A three-dimensional model of the catheter was constructed in the numerical simulation for the calculation of partial differential equation of a platelet activation model. A significant difference was detected by the expression of p-selectin comparing the group I (33.42 ± 4.74), group II (40.79 ± 5.54) and group III(51.00 ± 7.21) (p < 0.0001). The median values for GPIIb/IIIa were 10426 (10029-10721), 13921 (13412-15652) and 19946 (18714-21815) after catheter insertion (p < 0.0001), for groups I, II and III, respectively. Excluding the first arterial orifice, venous orifices tend to have greater platelet activation when compared to the other arterial orifices. The results of this study showed the influence of arterial and venous lateral orifices in stimulating the development of thrombi associated with the activation of platelet markers the longer the catheter was used.

Research progress of change of platelet in blood stasis syndrome and effect of traditional Chinese medicine / 中国中药杂志

The traditional Chinese medicine(TCM) syndrome of blood stasis refers to blood stagnation in meridians and viscera, with the main symptoms of pain, mass, bleeding, purple tongue, and unsmooth pulse. Cardiovascular and cerebrovascular diseases are among the major chronic diseases seriously harming the health of the Chinese. Among the coronary heart disease and stroke patients, most demonstrate the blood stasis syndrome. Platelet is considered to be one of the necessary factors in thrombosis, which closely relates to the TCM syndrome of blood stasis and the occurrence of cardiovascular and cerebrovascular diseases. The clinical and laboratory research on platelet activation and aggregation has been paid more and more attention. Its purpose is to treat and prevent blood stasis syndrome. In this study, the authors analyzed the research on the dysfunctions of platelets in blood stasis syndrome, biological basis of TCM blood stasis syndrome, and the effect of blood-activating stasis-resolving prescriptions on platelets, aiming at providing a reference for exploring the mechanism of platelet intervention in the treatment of TCM blood stasis syndrome and the pathways and targets of Chinese medicine in the prevention and treatment of the syndrome.

Effect of Vitamin D3 to Platelet Activation Mediated by Tumor Cell Culture Medium / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of vitamin D3 to platelet activation by tumor cell culture medium.@*METHODS@#The peripheral blood platelets of BALB/c mice were isolated. The platelets were activated in 4T1 culture fluid for 24 h. The platelets were divided into 7 groups: control group, activation group, 1 nmol/L vitamin D3 group, 10 nmol/L vitamin D3 group, 50 nmol/L vitamin D3 group, 100 nmol/L vitamin D3 group, and positive drug (0.1 μmol/L eptifibatide) group. CCK-8 assay was used to detect the platelet proliferation at 24, 48 and 72 h. Flow cytometry was used to detect the expression of CD61 and CD62p and receptor for advanced glycation end products (RAGE) at 24, 48 and 72 h. ELISA was used to detect the level of platelet-endothelial cell adhesion molecule-1 (PECAM-1) at 24, 48 and 72 h.@*RESULTS@#The CD41@*CONCLUSION@#Vitamin D3 shows antiplatelet effect and can inhibit platelet proliferation and activation.

Determinación de la viabilidad de los concentrados plaquetarios obtenidos de capa leucocitaria (buffy coat) durante siete días de almacenamiento / Monitoring of the Viability of Platelet Concentrates Obtained from Buffy Coat during Seven Days of Storage / Determinação da viabilidade de concentrados de plaquetas obtidos de camada leucocitária (buffy coat) durante sete dias de armazenamento

Introducción: los concentrados plaquetarios (CPG) son hemocomponentes lábiles afectados por varios factores, desde el método de obtención hasta las condiciones de almacenamiento, que provocan una paulatina pérdida de funcionalidad, por lo que es necesario evaluar parámetros de calidad que garanticen la viabilidad de las plaquetas durante los días de almacenamiento, con el propósito de monitorear el mantenimiento de las características funcionales de las plaquetas. Materiales y métodos: estudio descriptivo transversal, con un tamaño muestral de 64 cpq, evaluados a los 3, 5 y 7 días de almacenamiento. Los parámetros monitoreados fueron físicos, de almacenamiento y porcentaje de la activación plaquetaria mediante la medición de P-selectina (cd62) por citometría de flujo. Se aplicó el estadístico de chi cuadrado, Anova de un factor, Kruskall-Wallis y correlación de Pearson. Resultados: existen diferencias significativas al séptimo día con relación al tercer y quinto día de almacenamiento, especialmente en el parámetro de formación de remolino plaquetario o swirling (p < 0.005) y agregados plaquetarios (p = 0.001). La activación plaquetaria aumentó significativamente (p = 0.001) desde el quinto día. Conclusiones: la viabilidad de los cpq difiere con los días de almacenamiento, por lo que es necesario evaluar pH, formación de remo-linos y agregados a todos los cpq antes de ser transfundidos como indicativos de activación plaquetaria y disminución de su funcionalidad

Introduction: Platelet concentrates (cpq) are labile blood components affected by several factors from the method of production to storage conditions that cause a gradual loss of functionality. For this reason, it is necessary to evaluate the platelet quality parameters that guarantee the viability during the storage days, with the purpose of monitoring the maintenance of the functional characteristics of the platelets. Materials and methods: This cross-sectional descriptive study had a sample size of 64 platelet concen-trates, evaluated at 3, 5, and 7 days of storage. The monitored parameters were the physical storage parameters and percentage of platelet activation by measuring P-selectin (cd62) via flow cytometry. The chi-square statistic, one-way Anova, Kruskal­Wallis test, and Pearson correlation were applied. Results: Significant differences were observed on the 7th day in relation to the 3rd and 5th day of storage, espe-cially in the swirling parameter (p < 0.005) and platelet aggregates (p = 0.001). The platelet activation increased significantly (p = 0.001) on the 5th day. Conclusions: Based on the findings of this study, the viability of the platelet concentrates differs with the days of storage. For this reason, it is necessary to evaluate the swirling, pH, and aggregates to all platelet concentrates before being transfused as an indication of platelet activation and decreased functionality

Introdução: os concentrados de plaquetas (cpq) são hemocomponentes lábeis afetados por diversos fato-res, desde o método de obtenção até as condições de armazenamento que ocasionam uma perda grada-tiva de funcionalidade, sendo necessário avaliar os parâmetros de qualidade que garantem a viabilidade das plaquetas ao longo dos dias de armazenamento, a fim de monitorar a manutenção das características funcionais das plaquetas. Materiais e métodos: estudo descritivo transversal, com tamanho de amostra de 64 cpq, avaliados aos três, cinco e sete dias de armazenamento. Os parâmetros monitorados foram físicos, de armazenamento e porcentagem de ativação plaquetária pela dosagem de P-selectin (cd62) por citometria de fluxo. Os testes estatísticos aplicados incluíram o teste qui-quadrado, anovade um fator, teste de Kruskall-Wallis e correlação de Pearson. Resultados: há diferenças significativas no sétimo dia em relação ao terceiro e quinto dia de armazenamento, principalmente no parâmetro formação de rede-moinhos ou swirling de plaquetas (p < 0.005) e agregados plaquetários (p = 0.001). A ativação plaquetária aumentou significativamente (p = 0.001) a partir do quinto dia. Conclusões: a viabilidade dos concentra-dos de plaquetas difere com os dias de armazenamento, por isso é necessário avaliar o pH, a formação de redemoinhos e agregados a todos os concentrados de plaquetas antes de serem transfundidos como indicativo de ativação plaquetária e diminuição de sua funcionalidade

Alteraciones hematológicas en COVID-19 / Hematological Findings in COVID-19

Resumen El SARS (síndrome respiratorio agudo grave) es el estadio grave de la COVID-19 ocasionado por el SARS-CoV-2, que causa infecciones respiratorias en humanos y cuya transmisión se da principalmente por contacto. El virus ingresa a la célula huésped por la interacción de la proteína S con la enzima convertidora de angiotensina II (ACE2), presente en el tracto respiratorio, así como en monocitos, macrófagos, células endoteliales, corazón y tracto gastrointestinal. El aumento de IFN frena la replicación viral y activa la respuesta inmune adaptativa. Así, las manifestaciones clínicas de la infección se presentan frecuentemente a nivel del tracto respiratorio; sin embargo, también pueden involucrar otros sistemas como el hematopoyético. En el hemograma se observan recuentos celulares alterados, principalmente leucocitos y plaquetas. La linfopenia y neutrofilia se asocian con enfermedad severa y la trombocitopenia se presenta de manera heterogénea en la infección. Entre las complicaciones se encuentra la coagulación intravascular diseminada, producida cuando los monocitos y las células endoteliales son activadas por la liberación de citoquinas; esto genera daño endotelial, con la síntesis del factor tisular, secreción de factor tisular, activación plaquetaria y liberación del factor Von Willebrand, así como una condición hiperfibrinolítica especialmente en estadios tardíos de la infección. Las pruebas de laboratorio como el dímero D, los productos de degradación de la fibrina (PDF), tiempo de protrombina (TP), tiempo de tromboplastina parcial activado (TTPA), entre otras, son fundamentales para el diagnóstico, seguimiento y pronóstico de la enfermedad.

Abstract Severe Acute Respiratory Syndrome (SARS) is the serious condition of coronavirus (COVID-19) caused by SARS-COV-2 which causes respiratory infections in humans, and whose transmission is given mainly through the contact. this virus enters into the host cell due to the spike protein (S) interaction with the angiotensin-converting enzyme 2 (ACE2), which is not only present in the respiratory tract but also monocytes, macrophages, endothelial cells, the heart, and gastrointestinal tract. The increase in INF stops viral replication and activates the adaptive immune response. The infection's clinic manifestations often occur in the respiratory tract; however, other systems like the hematopoietic may be affected. Altered cell counts, mainly leukocytes and platelets, are seen on the blood count. Lymphopenia and neutrophilia are associated with severe disease; thrombocytopenia is present in a heterogeneous way in the infection. Among the disease's complications are the Disseminated Intravascular Coagulation (DIC) that results when monocytes and endothelial cells are activated because of the release of cytokines, causing endothelial damage, with the synthesis of the tissue factor, tissue factor discharge, platelet activation, and the von Willebrand factor release, generating a hyperfibrinolytic condition especially in the infection's late-stage. Laboratory tests such as D-dimer (D-D), Fibrinogen Degradation Products (FDP), Prothrombin Time (PT), Activated Partial Thromboplastin Time (APTT) among others, are essential to the diagnosis, monitoring, and prognosis of the disease.

Roles of Platelet Toll-like Receptors in Thrombosis / 中国医学科学院学报

Platelets are non-nuclear blood cells that are widely involved in physiological and pathological processes.Their main role is to participate in hemostasis and thrombosis.Toll-like receptors(TLRs)are innate immune receptors.Platelets express multiple TLRs and can promote thrombosis by recognizing ligand-induced platelet activation and aggregation.This article reviews the relationship between platelets/TLR and thrombosis and the roles of TLRs in the development of thrombotic diseases.

Low triiodothyronine syndrome is associated with platelet function in patients with nephrotic syndrome

SUMMARY OBJECTIVE The objective of this study was to investigate the effects of low triiodothyronine syndrome (LT3S) on platelet function and clotting factors in patients with nephrotic syndrome(NS). METHODS Patients with primary nephrotic syndrome were divided into two groups, normal thyroid function (group A) and LT3S (group B), based on whether they had LT3S or not. Healthy subjects were selected as the control group (group C). Blood coagulation function was detected in each group. The platelet activation function (CD62P, CD63) was determined by flow cytometry. The platelet aggregation rate was detected by an optical method using adenosine diphosphate and arachidonic acid as inducers. RESULTS The proportion of primary nephrotic syndrome with LT3S was 23.2% (69/298). Compared with group C, group A had higher CD62P and PAgTADP, and group B had higher CD62P, CD63, PAgTAA, and PAgTADP; the difference was statistically significant (all P < 0.05). There was no significant difference in renal pathology between group A and group B (X2 = 4.957, P = 0.421). Compared with group A, the 24-hour urine protein, CD63, PAgTAA, and PAgTADP were higher in group B, and APTT and Alb were lower. The difference was statistically significant (P < 0.05). Logistic regression analysis showed that LT3S was associated with CD36 (OR: 3.516; 95% CI: 1.742~8.186; P = 0.004) and PAgTAA (OR: 0.442; 95% CI: 1.001~1.251; P = 0.037). CONCLUSION NS patients are prone to LT3S. Patients with LT3S may have abnormal platelet activation and increase of platelet aggregation.

RESUMO OBJETIVO O objetivo deste estudo foi investigar os efeitos da síndrome do baixo triiodotironina (LT3S) na função plaquetária e nos fatores de coagulação em pacientes com síndrome nefrótica (SN). MÉTODOS Pacientes com síndrome nefrótica primária foram divididos em dois grupos, função tireoidiana normal (grupo A) e LT3S (grupo B), com base na presença ou não de LT3S. Indivíduos saudáveis foram selecionados como grupo de controle (grupo C). A função de coagulação do sangue foi analisada em cada grupo. A função de ativação plaquetária (CD62P, CD63) foi determinada por citometria de fluxo. A taxa de agregação plaquetária foi detectada por um método óptico usando adenosina difosfato e ácido araquidônico como indutores. RESULTADOS A proporção de síndrome nefrótica primária com LT3S foi de 23,2% (69/298). Em comparação com o grupo C, o grupo A apresentou níveis mais altos de CD62P e PAgTADP, e o grupo B apresentou maiores CD62P, CD63, PAgTAA e PAgTADP; a diferença teve significância estatística (P < 0,05). Não houve diferença significativa na patologia renal entre o grupo A e o grupo B (X2 = 4,957, P = 0,421). Em comparação com o grupo A, a proteína em urina de 24 horas, CD63, PAgTAA e PAgTADP foram maiores no grupo B, já APTT e Alb foram mais baixos. A diferença apresentou significância estatística (P < 0,05). A análise de regressão logística mostrou uma associação entre LT3S e CD36 (OR: 3,516; 95% IC: 1,742~8,186; P = 0,004) e PAgTAA (OR: 0,442; 95% IC: 1,001~1,251; P = 0,037). CONCLUSÃO Pacientes com síndrome nefrótica estão propensos à síndrome do baixo triiodotironina (LT3S). Pacientes com LT3S podem ter ativação plaquetária anormal e aumento da agregação plaquetária.

Platelet activation in inflammatory bowel disease / 中南大学学报(医学版)

Platelet lineage suggests that it plays a crucial role in immune responses. In recent years, many studies have found that platelet activation is closely related to the activity of inflammatory bowel disease. Activated platelets can release inflammatory mediators, and express surface molecules that mediate inflammation, interact with leukocytes and vascular endothelial cells. It provides a theoretical basis for antiplatelet drugs to treat the inflammatory bowel disease.

Effect of triptolide in improving platelet activation in patients with ankylosing spondylitis by regulating VEGFA,SDF-1,CXCR4 pathway / 中国中药杂志

The effect of triptolide( TP) on VEGFA,SDF-1,CXCR4 pathway were investigated in vitro to explore the mechanism in improving platelet activation in patients with ankylosing spondylitis( AS). Peripheral blood mononuclear cells( PBMC) were used for the experiment and divided into 4 groups: normal group( NC),model group( MC),triptolide group( TP),and AMD3100 group. The optimal concentration of TP was measured by the MTT method. The expressions of TNF-α,IL-1β,IL-4,IL-10,VEGFA and VEGFR were detected by ELISA. The expressions of SDF-1,CXCR4 and VEGFA were detected by real-time quantitative PCR( RT-qPCR).The expressions of SDF-1,CXCR4,VEGFA and VEGFR were detected by Western blot. The expression levels of CD62 p,CD40 L and PDGFA were detected by immunofluorescence. MTT results showed that medium-dose TP had the strongest inhibitory effect on cells at24 h. The results of ELISA and PCR showed that TP inhibited mRNA expressions of IL-1β,TNF-α,VEGFA,VEGFR and SDF-1,CXCR4 and VEGFA. The results of Western blot indicated that TP inhibited SDF-1,CXCR4 and VEGFA,VEGFR protein expressions; immunofluorescence results indicate that TP can inhibit the expressions of CD62 p,CD40 L,PDGFA. TP may regulate platelet activation by down-regulating SDF-1,CXCR4,VEGFA and VEGFR mRNA expressions,thereby down-regulating IL-1β and TNF-αexpressions,and up-regulating the expressions of IL-4 and IL-10 cytokines.

Predictive Effect of Platelet Activation Index Expression before and after Adenosine Bisphosphate Activation on Bleeding Risk in ITP Patients / 中国实验血液学杂志

OBJECTIVE@#To investigate the predictive effect of platelet activation index expression before and after adenosine bisphosphate activation on bleeding risk in patients with primary immune thrombocytopenia (ITP).@*METHODS@#Eighty-nine patients with ITP admitted in our hospital from January 2017 to October 2018 were selected and inrolled in ITP group, the bleeding scoreing and grading were performed by using the ITP-BAT for ITP patients, then 89 ITP patients were divided into 4 subgroups: nothing bleeding symptom group, mild bleeding symprom group, mode rate bleeding symptom group and severe bleeding symptom group according to bleeding scores and grades obtained from ITP-BAT detection. At the same time, 22 persons underwent the health physical examination were selected and enrolled in control group. The adenosine diphosphate (ADP) was used as activator for all patients and controls. The flow cytonetry was used to analyze the expression of platelet membranc glyco protein (GPⅠb, GPⅡb /Ⅲ a) and P-selectin before and after ADP activation, the multiple linear person's correlation analysis was used to analyze the correlation of bleeding degree of ITP patients before and after ADP acbivation with the expression levels of GPⅠb, GPⅡb/Ⅲa and P-selectin.@*RESULTS@#After the ADP activation, the expression level of GPⅠb significantly decreased, while the expression levels of GPⅠb, GPⅡb/Ⅲ a and P-selectin significantly increased in control group, nothing bleeding symptom group and mild bleeding symptom group; but the expression level of GPⅠb significantly increased, while the expression level of GPⅡb/Ⅲ a significantly decreased in moderate and severe bleeding symptom group, the both differences were statistically significant (P＜0.05). however, the expression level of P-selectin in moderate and severe bleeding symptom groups before and after ADP activation was not statistivally significant (P＞0.05). Before ADP activation, the expression level of GPⅠb in ITP subgroups was lower than that in control group, the expression level of GPⅡb/Ⅲ a in ITP subgroups was higher than that in control group, the expression level of P-selectin in moderate and severe bleeding symptom groups was higher than that in control group (P＜0.05). After ADP activation, the expression levels of GPⅠb and P-selectin in ITP subgroups both were lower than those in control group, the expression level of GPⅡb/Ⅲa in ITP subgroups was higher than that in control group (P＜0.05). The comparison among ITP subgroups showed that before ADP activation, the expression level of GPⅠb in moderate and severe bleeding symptom groups was lower than that in nothing bleeding symotom and mild bleeding symptom groups, while the expression levels of GPⅡb/Ⅲa and P-selectin were higher than those in nothing bleeding symptom and mild bleeding symptom groups (P＜0.05), however, after ADP activation, the expression level of GPⅠb in moderate and severe bleeding symptom groups was higher than that in nothing bleeding symptom and mild bleeding symptom groups, while the expression levels of GPⅡb/Ⅲ a and P-selection in moderate and severe bleeding symptom groups were lower than those in nothing and mild bleeding symptom groups (P＜0.05). The correlation analysis showed that before ADP activation, the expression levels of GPⅠb and GPⅡb/Ⅲa positivdy correlated with the bleeding risk (r=0.483, 0.504), and the P-selectin not correlated with the bleeding risk (r=0.000); however, after ADP activation, the expression level of GPⅠb and GPⅡb/Ⅲ a negatively correlated with the bleeding risk (r=-0.627, -0.406, -0.108).@*CONCLUSION@#The expression level of platelet activation indicators before and after ADP activation is of certain value for prevention of bleeding risk in ITP patients and can be used as a reference indicator for the treatment and efficacy evaluation.

Characterization of the distinct mechanism of agonist-induced canine platelet activation

Platelet activation has a major role in hemostasis and thrombosis. Various agonists including adenosine diphosphate (ADP) and thrombin interact with G protein-coupled receptors (GPCRs) which transduce signals through various G proteins. Recent studies have elucidated the role of GPCRs and their corresponding G proteins in the regulation of events involved in platelet activation. However, agonist-induced platelet activation in companion animals has not been elucidated. This study was designed to characterize the platelet response to various agonists in dog platelets. We found that 2-methylthio-ADP-induced dog platelet aggregation was blocked in the presence of either P2Y₁ receptor antagonist MRS2179 or P2Y₁₂ receptor antagonist AR-C69931MX, suggesting that co-activation of both the P2Y₁ and P2Y₁₂ receptors is required for ADP-induced platelet aggregation. Thrombin-induced dog platelet aggregation was inhibited in the presence of either AR-C69931MX or the PKC inhibitor GF109203X, suggesting that thrombin requires secreted ADP to induce platelet aggregation in dog platelets. In addition, thrombin-mediated Akt phosphorylation was inhibited in the presence of GF109203X or AR-C69931MX, indicating that thrombin causes Gi stimulation through the P2Y₁₂ receptor by secreted ADP in dog platelets. Unlike human and murine platelets, protease-activated receptor 4 (PAR4)-activating peptide AYPGKF failed to cause dog platelet aggregation. Moreover, PAR1-activating peptide SFLLRN or co-stimulation of SFLLRN and AYPGKF failed to induce dog platelet aggregation. We conclude that ADP induces platelet aggregation through the P2Y₁ and P2Y₁₂ receptors in dogs. Unlike human and murine platelets, selective activation of the PAR4 receptor may be insufficient to cause platelet aggregation in dog platelets.

Difference in Mean Platelet Volume between Migraine Patients with and without Aura

BACKGROUND: Mean platelet volume (MPV) increases when platelets are activated, and it is known to increase in migraine patients. The aim of this study is to investigate whether there is a difference in MPV or platelet count between migraine patients with (MA) and without aura (MO).METHODS: Migraine patients were recruited from the out-patient department of a hospital between January 2012 and June 2017. Patients were divided into MA and MO groups. Platelet count and MPV were compared between groups, and the frequency of comorbidities such as ischemic stroke and cardiovascular disease, was investigated in both groups.RESULTS: Of the 123 patients, 46 were classified as MA, and 77 were classified as MO. The MPV of the MA group was significantly higher than that of the MO group (8.92±0.17 fL, 6.32±0.28 fL, respectively) (P=0.034). However, platelet count showed no significant difference between groups. Cardiovascular disease and ischemic stroke incidences were significantly higher in the MA group than in the MO group (ischemic stroke: 15.2%, 7.8%, respectively, P=0.027; cardiovascular disease: 10.9%, 6.5%, respectively, P=0.018).CONCLUSION: Mean platelet volume was significantly greater in the MA group than in the MO group. This may be related to the pathophysiological differences between the two conditions.

Evaluating the effect of donor anxiety levels and lifestyle characteristics on the activation of platelet concentrates

BACKGROUND: Smoking, alcohol use, performing regular physical exercise, dietary habits, and anxiety level may cause platelet activation. We aimed to evaluate the anxiety levels, smoking status, alcohol intake, and sportive habits of donors, and determine their impact on the quality of apheresis-platelets.METHODS: State and Transient Anxiety Inventory (STAI) was used to determine the level of donors' anxiety. STAI has two subscales: S-anxiety scale (STAI-I) and T-anxiety scale (STAI-II), each comprising 20 questions rated on a 4-point Likert scale. Data on smoking, alcohol consumption, and performing regular physical exercise were obtained from a questionnaire filled out before donation. Flow cytometric analysis was used to quantify activated platelets.RESULTS: The STAI-I level of 86 participants was normal, while that of 12 was higher. No significant difference was found in the active platelet absolute count [1.8×10¹¹ (2.7) and 1.4×10¹¹ (1.3), respectively; P=0.665] between donors with normal STAI-I levels and those with higher STAI-I levels. Of 98 donors, 42 had normal STAI-II levels, while 56 had higher STAI-II levels. No significant difference was found in the active platelet absolute count [2.3×10¹¹ (3.1) and 1.5×10¹¹ (2.3), respectively; P=0.224] between donors with normal STAI-II levels and those with higher STAI-II levels. Platelet counts of individuals who perform regular physical exercise were significantly higher than those of individuals who did not perform regular physical exercise (6.3±1.4×10¹¹ vs. 5.5±1.4×10¹¹).CONCLUSION: The quality of apheresis platelets is not affected by anxiety levels and lifestyle characteristics of blood donors. There is no need to organize apheresis blood donor pool considering with these subjects.