In resting platelets, the 17 ^th domain of filamin a (FLNa17) constitutively binds to the platelet membrane glycoprotein Ibα (GPIbα) at its cytoplasmic tail (GPIbα-CT) and inhibits the downstream signal activation, while the binding of ligand and blood shear force can activate platelets. To imitate the pull force transmitted from the extracellular ligand of GPIbα and the lateral tension from platelet cytoskeleton deformation, two pulling modes were applied on the GPIbα-CT/FLNa17 complex, and the molecular dynamics simulation method was used to explore the mechanical regulation on the affinity and mechanical stability of the complex. In this study, at first, nine pairs of key hydrogen bonds on the interface between GPIbα-CT and FLNa17 were identified, which was the basis for maintaining the complex structural stability. Secondly, it was found that these hydrogen bonding networks would be broken down and lead to the dissociation of FLNa17 from GPIbα-CT only under the axial pull force; but, under the lateral tension, the secondary structures at both terminals of FLNa17 would unfold to protect the interface of the GPIbα-CT/FLNa17 complex from mechanical damage. In the range of 0~40 pN, the increase of pull force promoted outward-rotation of the nitrogen atom of the 563 ^rd phenylalanine (PHE ⁵⁶³-N) at GPIbα-CT and the dissociation of the complex. This study for the first time revealed that the extracellular ligand-transmitted axial force could more effectively relieve the inhibition of FLNa17 on the downstream signal of GPIbα than pure mechanical tension at the atomic level, and would be useful for further understanding the platelet intracellular force-regulated signal pathway.
Filamins/metabolism* ; Platelet Glycoprotein GPIb-IX Complex/metabolism* ; Molecular Dynamics Simulation ; Ligands ; Protein Binding ; Blood Platelets/metabolism* ; von Willebrand Factor/metabolism*

Platelets not only have hemostatic function, but can also directly or indirectly recognize pathogenic microorganisms and the signals they produce to capture and destroy them through membrane receptors. They can collaborate with various components of the body's immune system by releasing of intraplatelet particulate matter, cytokines and chemokines to perform bactericidal functions. And it can also play a bactericidal role by swallowing pathogens, releasing antimicrobial proteins and chemokines and activating and enhancing other specialized anti-inflammatory cells bactericidal effect, such as leukocytes and so on. However, the bacteriostatic composition and bacteriostatic mechanism of platelets remain unclear, so attention should be paid to the immune mechanism and bacteriostatic effect of platelets.
Blood Platelets ; Anti-Bacterial Agents/pharmacology* ; Cytokines ; Leukocytes ; Particulate Matter

OBJECTIVE: To investigate the correlation of peripheral blood platelet/lymphocyte ratio (PLR) with Treg and Th17 and its influence on prognosis in newly diagnosed multiple myeloma (MM). METHODS: One hundred thirty-five newly diagnosed multiple myeloma patients admitted to the Department of Hematology of Zhengzhou People's Hospital from June 2015 to October 2022 were selected as MM group. Clinical data included sex, age, immune typing, ISS stage, blood calcium (Ca), albumin (ALB), hemoglobin (Hb), PLR, LDH, β₂ microglobulin (β₂-MG), Treg and Th17 levels. Sixty healthy volunteers who underwent physical examination in our hospital during the same period were selected as the control group. PLR, Treg and Th17 levels in MM group and control group were compared. Pearson was used to analyze the correlation between PLR and Treg, Th17. The relationship between MM patients with different PLR and clinical features and prognosis was analyzed. RESULTS: The PLR and Th17 of MM patients were significantly higher than that of control group, and Treg was significantly lower than that of control group (P<0.05). In MM patients, PLR was negatively correlated with Treg (r=-0.616), and PLR was positively correlated with Th17 (r=0.555). Using mean PLR=132.72 as the boundary, 135 MM patients were divided into high PLR group (n=54) and low PLR group (n=81). In MM patients with high PLR, ISS stage, ALB and Treg were significantly higher than those in low PLR group, while Th17 was significantly lower than those in low PLR group (P<0.05). By univariate and COX regression analysis, PLR was an independent prognostic risk factor for newly diagnosed MM patients (P<0.05). MM patients with high PLR had better PFS and OS, and the difference was statistically significant compared with MM patients with low PLR (P<0.05). 65 patients admitted from June 2015 to December 2018 were used as the training set, and 70 patients admitted from January 2019 to October 2022 were used as the validation set. The OS of MM patients with different PLR were compared respectively. The results showed that the conclusions of the training set and the validation set were consistent. PLR with high expression had higher OS (P<0.01). CONCLUSION PLR is correlated with Treg and Th17 in newly diagnosed MM patients, and high PLR has better prognosis. PLR can be used to evaluate the prognosis of MM patients.
Humans ; Multiple Myeloma/diagnosis* ; Blood Platelets ; T-Lymphocytes, Regulatory ; Prognosis ; Th17 Cells ; Retrospective Studies

OBJECTIVE: To investigate the changes of platelet count (PLT), plateletcrit (PCT), mean platelet volume (MPV) and platelet distribution width (PDW) before and after apheresis platelet transfusion, the correlation between the parameters and their clinical significance. METHODS: A total of 38 patients who received apheresis platelet transfusion were selected, their results of blood routine test closest to the time point of apheresis platelet transfusion were consulted from hospital information system and the changes of PLT, PCT, MPV and PDW were compared before and after transfusion. The correlation between above parameters was analyzed. The correlation of body mass index (BMI) with the increased multiple and increased value after platelet infusion was also analyzed. RESULTS: Compared with pre-infusion, PLT and PCT significantly increased (both P <0.001) while MPV and PDW showed no significant difference after apheresis platelet transfusion (P >0.05). The difference of PLT and PCT before and after apheresis platelet transfusion had no correlation with PLT and PCT before transfusion (r =0.002, r =0.001), while the difference of MPV and PDW was negatively correlated with MPV and PDW before transfusion (r =-0.462, r =-0.610). The PLT growth rate was positively correlated with PCT growth rate before and after apheresis platelet transfusion (r =0.819). BMI was positively correlated with the increased multiple of PLT after infusion (r =0.721), but not with the increased value of PLT after infusion (r =0.374). CONCLUSION Apheresis platelet transfusion can cause platelet parameters change and shows different characteristics. Characteristic changes of platelet parameters and their correlation can be used as reference indices to evaluate the efficacy of apheresis platelet transfusion.
Humans ; Mean Platelet Volume ; Platelet Transfusion ; Blood Platelets ; Platelet Count/methods* ; Blood Component Removal

Humans ; Female ; Blood Platelets ; Ovarian Neoplasms/diagnosis*

Objective: To explore the influence factors of poor prognosis of esophageal squamous cell carcinoma (ESCC) and the predictive value of inflammatory reaction indexes including neutrophils and lymphocytes ratio (NLR), platelet and lymphocyte ratio (PLR), monocyte and lymphocyte ratio (MLR) provision and differentiation degree, infiltration depth, lymph node metastasis number on the postoperative recurrence of ESCC. Methods: A total of 130 patients with ESCC who underwent radical resection from February 2017 to February 2019 in Nanyang Central Hospital were selected and divided into good prognosis group (66 cases) and poor prognosis group (64 cases) according to the prognostic effect. The clinical data and follow-up data were collected. Multivariate logistic regression analysis was used to determine the independent influencing factors of poor prognosis. Spearman correlation analysis was used to determine the correlation between preoperative NLR, PLR and MLR with the degree of differentiation, depth of invasion and number of lymph node metastases. Receiver operating characteristic (ROC) curve analysis was used to evaluate the efficacy of NLR, PLR and MLR in predicting poor prognosis of ESCC. Results: Univariate analysis showed that the degree of differentiation, the degree of invasion and the number of lymph node metastasis were related to the prognoses of patients with ESCC (P<0.05). Multivariate logistic regression analysis showed that the degree of differentiation, depth of invasion and number of lymph node metastases were independent influencing factors for poor prognosis of patients with ESCC, moderate differentiation (OR=2.603, 95% CI: 1.009-6.715) or low differentiation (OR=9.909, 95% CI: 3.097-31.706), infiltrating into fibrous membrane (OR=14.331, 95% CI: 1.333-154.104) or surrounding tissue (OR=23.368, 95% CI: 1.466-372.578), the number of lymph node metastases ≥ 3 (OR=9.225, 95% CI: 1.693-50.263) indicated poor prognosis. Spearman correlation analysis showed that NLR was negatively correlated with the degree of differentiation and the number of lymph node metastases (r=-0.281, P=0.001; r=-0.257, P=0.003), PLR was negatively correlated with the degree of differentiation, depth of invasion and number of lymph node metastasis (r=-0.250, P=0.004; r=0.197, P=0.025; r=-0.194, P=0.027), MLR was positively correlated with the degree of differentiation and the number of lymph node metastasis (r=0.248, P=0.004; r=0.196, P=0.025). ROC curve analysis showed that the areas under the curve of NLR, PLR and MLR in predicting poor prognosis of ESCC were 0.971, 0.925 and 0.834, respectively. The best cut-off value of NLR was 2.87. The sensitivity and specificity of NLR in predicting poor prognosis of ESCC were 90.6% and 87.9%, respectively. The optimal cut-off value of PLR was 141.75. The sensitivity and specificity for predicting poor prognosis of ESCC were 92.2% and 87.9%, respectively. The best cut-off value of MLR was 0.40. The sensitivity and specificity of MLR in predicting poor prognosis of esophageal squamous cell carcinoma were 54.7% and 100.0%, respectively. Conclusions: The degree of differentiation, the degree of invasion and the number of lymph node metastases are closely related to the poor prognosis of patients with esophageal squamous cell carcinoma. NLR, PLR and MLR can provide important information for predicting the poor prognosis of esophageal squamous cell carcinoma.
Humans ; Esophageal Squamous Cell Carcinoma/pathology* ; Prognosis ; Lymphatic Metastasis/pathology* ; Esophageal Neoplasms/pathology* ; Neutrophils ; Lymphocytes ; Blood Platelets/pathology* ; Inflammation ; Retrospective Studies

Acute coronary syndrome (ACS),with increasing mortality year by year,has become a major public health problem in China.Exercise rehabilitation as an important part of the out-of-hospital rehabilitation for the patients with heart diseases can further reduce the mortality of patients on the basis of drug treatment.The available studies have proved that high-intensity interval training (HIIT) is more effective and efficient than moderate-intensity continuous training (MICT) such as walking and jogging on chronic cardiovascular diseases such as heart failure,stable coronary heart disease,and hypertension and has high security.According to the latest research,HIIT can reduce the platelet response,mitigate myocardial ischemia-reperfusion injury,and increase the exercise compliance of ACS patients more significantly than MICT.Moreover,it does not increase the risk of thrombotic adverse events or malignant arrhythmia.Therefore,HIIT is expected to become an important part of exercise prescription in out-of-hospital cardiac rehabilitation strategy for the patients with ACS.
Humans ; Cardiac Rehabilitation ; High-Intensity Interval Training ; Acute Coronary Syndrome ; Heart Failure ; Blood Platelets

OBJECTIVES: The number of gestational women has been increased in recent years, resulting in more adverse pregnancy outcomes. It is crucial to assess the coagulation function of pregnant women and to intervene in a timely manner. This study aims to analyze the influencing factors on thrombelastography (TEG) and explore the evaluation of TEG for gestational women. METHODS: A retrospective study was conducted on 449 pregnant women who were hospitalized in the obstetrics department in Xiangya Hospital of Central South University from 2018 to 2020. We compared the changes on the TEG parameters among normal pregnant women between different age groups, different ingravidation groups, and different stages of pregnancy groups. The influence on TEG of hypertensive disorders in pregnancy (HDP) and gestational diabetes mellitus (GDM) as well as two diseases synchronization was explored. RESULTS: Compared with the normal second trimester women, the R values and K values of TEG were increased, and α angle, CI values and LY30 values were decreased in third trimester women (all P<0.05). Compared with normal group, the R values and CI values of TEG of the HDP group have significant difference (both P<0.05). There were no significant difference of TEG between the GDM group, the HDP combined with GDM group and the normal group (all P>0.05). Multiple linear regression analysis showed that the influencing factors for R value in TEG were weeks of gestation (P<0.001) and mode of conception (P<0.05), for α angle was weeks of gestation (P<0.05), for MA value was mode of conception (P<0.05), and for CI value was weeks of gestation (P<0.05). The analysis of correlation between TEG with platelet (PLT) and coagulation routines represented that there was a correlation between TEG R values and activated partial thromboplastin time (APTT) (P<0.01), and negative correlation between TEG CI values and APTT (P<0.05). There was a negative correlation between TEG K values and FIB (P<0.05). The correlation of α angle (P<0.05), MA values (P<0.01) and CI values (P<0.05) with FIB were positive respectively. CONCLUSIONS The TEG parameters of 3 stages of pregnancy were different. The different ingravidation approach has effect on TEG. The TEG parameters were consistent with conventional coagulation indicators. The TEG can be used to screen the coagulation status of gestational women, recognize the abnormalities of coagulation and prevent the severe complication timely.
Female ; Humans ; Pregnancy ; Thrombelastography/methods* ; Blood Coagulation Tests/methods* ; Retrospective Studies ; Blood Coagulation ; Blood Platelets ; Diabetes, Gestational/diagnosis*

Activated platelets may interact with various types of leukocytes such as monocytes, neutrophils, dendritic cells, and lymphocytes, trigger intercellular signal transduction, and thus lead to thrombosis and synthesis of massive inflammatory mediators. Elevated levels of circulating platelet-leukocyte aggregates have been found in patients with thrombotic or inflammatory diseases. This article reviews the latest research on the formation, function, and detection methods of platelet-leukocyte aggregates and their role in the onset of Kawasaki disease, so as to provide new ideas for studying the pathogenesis of Kawasaki disease.
Humans ; Mucocutaneous Lymph Node Syndrome/etiology* ; Blood Platelets ; Inflammation Mediators ; Leukocytes ; Neutrophils

OBJECTIVE: To explore the effects of Ena/VASP gene family on the expression of glycoprotein (GP) Ib-IX complex in human megakaryoblastic leukemia Dami cells. METHODS: SiRNAs targeting Ena/VASP gene family were designed and synthesized to interfere Enah, EVL and VASP gene expression. When the siRNAs were transfected into Dami cells by using Lipofectamine^TM 2000 for 48 h, the expression of GPIb-IX complex was detected by quantitative real-time PCR, Western blot and flow cytometry. RESULTS: We successfully established siVASP , siEVL and si Enah Dami cell lines. And it was found that the expression of GPIb-IX complex had no evident reduction in siEVL or siVASP Dami cells at both mRNA and protein level, while the total protein and membrane protein of GPIb-IX complex were obviously reduced when Enah was knocked down. CONCLUSION Enah could affect the expression of GPIb-IX complex in human megakaryoblastic leukemia Dami cells, but the underlying mechanism still needs to be further explored.
Humans ; Cell Line ; Platelet Glycoprotein GPIb-IX Complex/metabolism* ; Leukemia/metabolism* ; Blood Platelets/metabolism*