Hypoxemia is a common pathological state characterized by low oxygen saturation in the blood. This condition compromises mucosal barrier integrity particularly in the gut and oral cavity. However, the mechanisms underlying this association remain unclear. This study used periodontitis as a model to investigate the role of platelet activation in oral mucosal immunopathology under hypoxic conditions. Hypoxia upregulated methyltransferase-like protein 4 (METTL4) expression in platelets, resulting in N⁶-methyladenine modification of mitochondrial DNA (mtDNA). This modification impaired mitochondrial transcriptional factor A-dependent cytosolic mtDNA degradation, leading to cytosolic mtDNA accumulation. Excess cytosolic mt-DNA aberrantly activated the cGAS-STING pathway in platelets. This resulted in excessive platelet activation and neutrophil extracellular trap formation that ultimately exacerbated periodontitis. Targeting platelet METTL4 and its downstream pathways offers a potential strategy for managing oral mucosa immunopathology. Further research is needed to examine its broader implications for mucosal inflammation under hypoxic conditions.
DNA, Mitochondrial/metabolism* ; Mouth Mucosa/pathology* ; Hypoxia/immunology* ; Methyltransferases/metabolism* ; Blood Platelets/metabolism* ; Animals ; Periodontitis/immunology* ; Humans ; Platelet Activation ; Mice

Gliomas are the most common primary neuroepithelial tumors of the central nervous system in adults, of which glioblastoma is the deadliest subtype. Apart from the intrinsically indestructible characteristics of glioma (stem) cells, accumulating evidence suggests that the tumor microenvironment also plays a vital role in the refractoriness of glioblastoma. The primary functions of platelets are to stop bleeding and regulate thrombosis under physiological conditions. Furthermore, platelets are also active elements that participate in a variety of processes of tumor development, including tumor growth, invasion, and chemoresistance. Glioma cells recruit and activate resting platelets to become tumor-educated platelets (TEPs), which in turn can promote the proliferation, invasion, stemness, and chemoresistance of glioma cells. TEPs can be used to obtain genetic information about gliomas, which is helpful for early diagnosis and monitoring of therapeutic effects. Platelet membranes are intriguing biomimetic materials for developing efficacious drug carriers to enhance antiglioma activity. Herein, we review the recent research referring to the contribution of platelets to the malignant characteristics of gliomas and focusing on the molecular mechanisms mediating the interaction between TEPs and glioma (stem) cells, as well as present the challenges and opportunities in targeting platelets for glioma therapy.
Humans ; Glioma/metabolism* ; Blood Platelets/physiology* ; Brain Neoplasms/pathology* ; Tumor Microenvironment

Objective To evaluate whether Vibrio vulnificus secreted exotoxin-hemolysin (VVH) can activate platelet, an important blood immune cell, and to explore the possible molecular mechanism of platelet activation by VVH. Methods Transcriptomics and immunohistochemistry were used to analyze whether Vibrio vulnificus infection caused platelet activation in mice. Then, flow cytometry was used to identify whether VVH was the main stimulator of platelet activation. Naturally expressed VVH toxin was purified and prepared. The effects of extracellular and intracellular Ca²⁺ signal inhibitors on VVH activated platelets were evaluated by flow cytometry and Western blotting. The immune activation effect of VVH in the early stage of Vibrio vulnificus infection was analyzed in vivo. Results VVH was the main stimulator of platelet activation in Vibrio vulnificus culture supernatant. Natural VVH can induce the increase of P-selectin (CD62P) on platelet surface, the formation of platelet-neutrophil complex (PNC), and the release of platelet microvesicles. The activation mechanism may be related to the VVH pore-dependent Ca²⁺-calmodulin (CaM) -myosin light chain kinase (MLCK) signaling pathway, which led to the release of platelet alpha particles and cascade activation of platelets. In a mouse model of ALD infected by Vibrio vulnificus gavage, VVH was strongly associated with platelet activation. Conclusion This study shows that VVH is an important platelet activating molecule in the early stage of Vibrio vulnificus infection, and its induction of platelet activation may be related to the pathogenic process.
Animals ; Platelet Activation/drug effects* ; Hemolysin Proteins/pharmacology* ; Vibrio vulnificus/metabolism* ; Mice ; Blood Platelets/drug effects* ; Vibrio Infections/immunology* ; P-Selectin/metabolism* ; Bacterial Proteins ; Female

Objective To analyze the distribution of platelet antibodies in hospitalized patients and explore the clinical significance of platelet antibody detection. Methods A total of 95 987 hospitalized patient cases from a tertiary hospital in Xi'an from April 1, 2021 to December 31, 2023 were collected. Platelet antibodies were detected by solid-phase agglutination method. Statistical analysis was performed on variables including gender, age, blood type, department, history of blood transfusion, pregnancy history, and disease type. Results Among 95 987 hospitalized patients, the positive rate of platelet antibody detection reached 4.35%. The positive rate of platelet antibodies in female hospitalized patients (5.29%) was higher than that in male patients (3.31%), and the difference was statistically significant (x²=224.124). The positive rate of platelet antibodies in those with pregnancy history (7.92%) was higher than that in those without pregnancy history (4.19%), and the difference was significant (x²=292.773). Similarly, the positive rate of platelet antibodies in those with transfusion history (7.79%) was higher than that in those without transfusion history (3.97%), and the difference was significant (x²=300.209). There was a significant correlation between the positive rate of platelet antibodies and the number of pregnancies (x²=91.061). Conclusion The positive rate of platelet antibodies in 95 987 inpatient cases was 4.35%. The positive rate of platelet antibodies had a close relationship with a history of blood transfusions and pregnancies, and it increased with the number of pregnancies. For patients with multiple transfusion histories and pregnancy histories, screening for platelet antibodies holds significant diagnostic value.
Humans ; Female ; Male ; Adult ; Middle Aged ; Blood Platelets/immunology* ; Inpatients ; Aged ; Pregnancy ; Young Adult ; Adolescent ; Aged, 80 and over ; Autoantibodies/blood*

Objective To investigate the therapeutic efficacy of HLA-genotype matched platelet transfusion using a platelet donor database for severe platelet transfusion refractoriness (PTR) caused by HLA antigen-antibody incompatibility. Methods Using real-time quantitative PCR (qPCR) to identify he patient's HLA class I genotype, followed by searching the platelet donor database for matching donors, and selecting highly compatible donors for transfusion. Platelets with higher compatibility levels were prioritized for transfusion recommendations. Results Among the 19 patients studied, 7 patients identified donors with B2U or higher compatibility, 6 patients identified donors with BX or higher compatibility, and 6 patients did not find a suitable donor. The transfusion efficacy was evaluated by calculating the corrected count increment (CCI) 24 hours post-transfusion, and all transfusions were effective. Conclusion The optimal strategy to prevent and treat patients with severe platelet transfusion refractoriness is to ensure patients receive platelet transfusions that are matched to their HLA genes, and this approach significantly enhances transfusion efficacy.
Humans ; Platelet Transfusion/adverse effects* ; HLA Antigens/immunology* ; Male ; Middle Aged ; Female ; Adult ; Blood Platelets/immunology* ; Aged ; Genotype

Trauma is the main cause of death and disability. Patients with severe trauma have hemorrhagic shock, traumatic coagulopathy and other diseases, which increase the risk of death. Platelets are important in the hemostatic response, but their function is rapidly dysregulated in trauma patients, leading to traumatic coagulopathy, blood loss, and early death. In addition to their role in hemostasis, platelets act as coordinators of the initial immune response, which can lead to immunothrombosis, organ dysfunction, and increased late mortality. At present, the treatment of post traumatic platelet dysfunction is mainly based on early hemostasis, and late prevention and treatment of thrombosis and organ dysfunction. In this review, the characteristics, underlying mechanisms, diagnosis and treatment strategies of platelet dysfunction in different periods are summarized, to provide ideas for studying the mechanism of platelet dysfunction after trauma and the treatment strategy for trauma patients.
Humans ; Wounds and Injuries/therapy* ; Blood Platelets/metabolism* ; Blood Platelet Disorders/etiology* ; Animals ; Hemostasis

OBJECTIVES: To evaluate the efficacy and safety of avatrombopag in promoting platelet engraftment after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in children, compared with recombinant human thrombopoietin (rhTPO). METHODS: A retrospective analysis was conducted on 53 pediatric patients who underwent allo-HSCT at the Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences from April 2023 to August 2024. Based on medications used during the periengraftment period, patients were divided into two groups: the avatrombopag group (n=15) and the rhTPO group (n=38). RESULTS: At days 14, 30, and 60 post-transplant, platelet engraftment was achieved in 20% (3/15), 60% (9/15), and 93% (14/15) of patients in the avatrombopag group, and in 39% (15/38), 82% (31/38), and 97% (37/38) in the rhTPO group, respectively. There were no significant differences between the two groups in platelet engraftment rates at each time point, cumulative incidence of platelet engraftment, overall survival, and relapse-free survival (all P>0.05). Multivariable Cox proportional hazards analysis indicated that acute graft-versus-host disease was an independent risk factor for delayed platelet engraftment (P=0.043). CONCLUSIONS In children undergoing allo-HSCT, avatrombopag effectively promotes platelet engraftment, with efficacy and safety comparable to rhTPO, and represents a viable therapeutic option.
Humans ; Retrospective Studies ; Hematopoietic Stem Cell Transplantation/adverse effects* ; Male ; Female ; Child ; Child, Preschool ; Infant ; Adolescent ; Transplantation, Homologous ; Blood Platelets/drug effects* ; Thiazoles/therapeutic use* ; Thrombopoietin/therapeutic use* ; Thiophenes

OBJECTIVE: To analyze the occurrence of arterial events and platelet parameters in patients with polycythemia vera (PV) and essential thrombocythemia (ET), and to explore the characteristics of platelet parameters in patients with PV and ET and their relationship with arterial complications. METHODS: The clinical and laboratory data of newly diagnosed PV and ET patients who visited the Department of Hematology, Beijing Anzhen Hospital, Capital Medical University from August 2017 to August 2022 were retrospectively analyzed. RESULTS: 86 MPN patients (46 males and 40 females) were enrolled, including 44 PV patients and 42 ET patients, with an median age of 61(23-83) years. The mutation rate of JAK2V617F gene, the number of megakaryocytes in bone marrow, the incidence of splenomegaly, and the levels of white blood cell count (WBC), hemoglobin (HGB), hematocrit (HCT), platelet distribution width (PDW), mean platelet volume (MPV), platelet-large cell ratio (P-LCR) in PV patients were significantly higher than those in ET patients (P < 0.05), while the levels of PLT and PCT were significantly lower than those in ET patients (P < 0.01). 22 cases (50%) of PV patients were complicated with arterial events, of which 12 had arterial stenosis in≥2 locations. Among arterial events, the PDW of PV patients with ischemic stroke was greater than that of PV patients without ischemic stroke (P =0.003), and the PDW of PV patients with arterial stenosis in≥2 locations was greater than that of PV patients with arterial stenosis in≤1 location (P =0.037). 23 cases (54.8%) of ET patients were complicated with arterial events, and 7 cases had arterial stenosis in≥2 locations. In arterial events, the PCT of ET patients complicated with ischemic stroke was greater than that of ET patients without ischemic stroke (P =0.037), and the PCT of ET patients with≥2 locations of arterial stenosis was greater than that of ET patients with≤1 location of arterial stenosis (P =0.049). The binary logistic regression analysis showed that elevated PDW and PCT were risk factors for ischemic stroke in PV and ET patients, respectively (P < 0.05). CONCLUSION The platelet parameters of PV and ET patients exhibit significantly different characteristics. Elevated PDW and PCT can predict a higher risk of ischemic stroke in PV and ET patients, respectively.
Humans ; Middle Aged ; Female ; Male ; Aged ; Retrospective Studies ; Adult ; Thrombocythemia, Essential/blood* ; Myeloproliferative Disorders/complications* ; Aged, 80 and over ; Polycythemia Vera/blood* ; Blood Platelets ; Platelet Count ; Young Adult ; Mean Platelet Volume

OBJECTIVE: To compare and analyze the changes of aggregation rate and routine parameters of platelets stored in temperature cycle, cold storage at 4 ℃ and oscillating storage at 22 ℃, so as to provide more experimental data for platelet preservation methods. METHODS: Blood samples were collected at 5 time points on the 1^st, 2^nd, 3^rd, 4^th and 6^th day after platelet cycling preservation at temperature, cold storage at 4 ℃, and oscillating storage at 22 ℃. Platelet maximum aggregation rate (MAR) and routine parameters including platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW) and platelet-larger cell ratio (P-LCR) were detected. RESULTS: The platelet MAR of three groups showed a significant decrease trend with the preservation time, the fastest decrease was in the 22 ℃ group, the slowest was in the 4 ℃ group, and the temperature cycle group was between the two groups. On the 3^rd day of preservation, the platelet MAR in 4 ℃ group was still in the normal range (MAR>60%), while in temperature cycle group was about 50%, and in 22 ℃ group was the lowest. On the 4^th day of preservation, platelet MAR in all the three groups was lower than 50%, and that in temperature cycle group was significantly lower than in 4 ℃ group but higher than in 22 ℃ group (both P < 0.05). On the 6^th day of preservation, platelet MAR in the temperature cycle group was significantly lower than that in the 4 ℃ group ( P <0.05), but there was no statistically significant difference compared to 22 ℃ group (P >0.05). PLT values in the three groups were all significantly decreased with the preservation time extension, and were significantly lower than those in the early stage of preservation within 6 days (all P < 0.05). PDW in temperature cycle group had no significant change within 6 days of preservation, but MPV and P-LCR were significantly increased. MPV, PDW and P-LCR all decreased significantly in 4 ℃ group within 6 days of preservation but increased in 22 ℃ group. Under the same storage days, PLT value of temperature cycle group had no significant difference with that of 4 ℃ group and 22 ℃ group, while MPV, PDW and P-LCR values were significantly higher than 4 ℃ group but lower than 22 ℃ group (all P < 0.05). CONCLUSION The aggregation function and routine parameters changes of temperature circulating preserved platelets are between 4 and 22 ℃.
Humans ; Platelet Aggregation ; Blood Preservation/methods* ; Temperature ; Blood Platelets ; Platelet Count ; Mean Platelet Volume ; Cryopreservation/methods* ; Cold Temperature

OBJECTIVE: To investigate the effects of oridonin on platelet function and related mechanisms. METHODS: Washed platelets from healthy adults and mice were incubated with different concentrations of oridonin (2.5, 5 and 10 μmol/L) in vitro . The surface expression level of P-selectin and the activation of integrin αIIbβ3 in platelets were detected by flow cytometry, and the aggregation ability of platelets under the stimulation by various agonists was detected by light transmission aggregometry. The expression of P-AKT (Ser473) was detected by protein immunoblotting. Arterial thrombosis model was established in mice with mesenteric injury induced by ferric chloride, and tail hemorrhage model was established by cutting off the tail of mice. The effect of intraperitoneal injection of oridonin (10 mg/kg) on thrombosis and haemostasis was tested. RESULTS: Oridonin inhibited platelet P-selectin expression and integrin αIIbβ3 activation. In the presence of different stimulants, oridonin inhibited platelet aggregation in a concentration-dependent manner. The phosphorylation level of AKT Ser473 was reduced in the groups treated with different concentrations of oridonin. Oridonin significantly prolonged the time of mesenteric artery thrombosis in mice, but did not affect the tail bleeding time. CONCLUSION Oridonin inhibits platelet activation, aggregation, and thrombosis by inhibiting AKT phosphorylation, and may be used as a potential antiplatelet drug.
Diterpenes, Kaurane/pharmacology* ; Animals ; Mice ; Blood Platelets/drug effects* ; Platelet Aggregation/drug effects* ; P-Selectin/metabolism* ; Thrombosis ; Platelet Glycoprotein GPIIb-IIIa Complex/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; Humans ; Phosphorylation ; Platelet Activation/drug effects*