No abstract

The role of phosphatidylserine (PS)-mediated procoagulant activity (PCA) in stroke remains unclear. To ascertain this role, early dynamic evolution of PS exposure on blood cells and released microparticles (MPs) and the corresponding PCA were evaluated in patients with acute ischemic stroke (AIS). Flow cytometry analyses revealed that initial levels of PS exposure on erythrocyte, platelet, and leukocyte were 2.40-, 1.36-, and 1.38-fold higher, respectively, in AIS than the risk factor-matched (RF) controls. Concomitantly, total PS MPs were increased in AIS (1949 ± 483/μl) compared with the RF group (1674 ± 387/μl; P = 0.019) and healthy controls (1052 ± 179/μl; P < 0.001). Specifically, PS erythrocytes gradually increased within 1 week. PS platelets and MPs peaked at 24 h and declined at 7 days, while PS leukocytes were markedly elevated at 24 h. Further, PS exposure on blood cells and MPs in stroke resulted in shortened clotting time with an accompanying increase in FXa and thrombin formation significantly. Treatment with lactadherin, a PS antagonist, delayed the coagulation time by approximately 20 % and blocked the generation of FXa and thrombin by about 50 %. Furthermore, initial counts of PS platelets and platelet MPs significantly correlated with stroke severity. Thrombin generation promoted by platelets and MPs at 12 h was significantly higher in patients with cardioembolism than in patients without. The thrombophilic susceptibility of AIS patients can be partly ascribed to PS exposure on blood cells and the release of MPs. Our studies identify PS exposure as a potentially novel therapeutic target in the treatment of AIS.

Oral squamous cell carcinoma (OSCC), the subtype of head and neck cancers, is notorious for its high incidence and death rate. The role of long non-coding RNAs (lncRNAs) is discovered to be significant for the canceration and cancer progression. Long intergenic non-protein coding RNA 958 (LINC00958) is discovered as a carcinogene in multiple cancers, such as gastric cancer, pancreatic cancer, and glioma, but there has been no report about how LINC00958 functions in OSCC. The objective of our study is to unfold function and mechanism investigation on LINC00958 in OSCC. First, TCGA database showed the upregulation and prognostic significance of LINC00958 in head and neck squamous carcinoma. Then, we discovered in OSCC clinical samples that LINC00958 presented high expression and predicted poor prognosis. Also, LINC00958 was elevated in OSCC cells. In vitro gain-and loss-function experiments proved that LINC00958 facilitated cell growth, retarded apoptosis, accelerated migration, and epithelial-to-mesenchymal transition (EMT) in OSCC. Mechanistically, we confirmed the cytoplasmic expression of LINC00958 in OSCC cells, and revealed that LINC00958 sequestered miR-627-5p to upregulate YBX2 expression. Rescue assays indicated that LINC00958 regulated OSCC cell proliferation, motility and EMT through YBX2. Together, we showed that LINC00958 promoted OSCC progression through miR-627-5p/YBX2 axis, indicating LINC00958 as a new prognostic marker, and provided new perspectives for molecular targeted treatment for OSCC.

Abstract.Interaction between the programmed cell death ligand 1 (PD-L1) and programmed cell death 1 (PD-1) contributes to tumor cell resistance to chemotherapeutic agents. PD-L1 is expressed in the cells of diffuse large B-cell lymphoma (DLBCL), one common type of malignant non-Hodgkin lymphomas. However, little is known about how the PD-1/PD-L1 pathway functions in the pathogenesis of DLBCL. Therefore, the present study investigated whether and how the PD-1/PD-L1 axis is involved in regulating the sensitivity of CRL2631, a DLBCL cell line, to the CHOP (Cyclophosphamide, Hydroxydaunorubicin/adriamycin, Oncovin/vincristine and Prednisone) chemotherapeutic regimen. CHOP treatment significantly decreased cell survival rate and increased apoptosis in CRL2631 cells. The application of recombinant human PD-1 (rPD-1) significantly decreased the cytotoxic effects of the CHOP regimen in CRL2631 cells, but not in the CRL2631 cells with PD-L1 deficiency. In the CRL2631 cells, rPD-1 enhanced the activity of the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt1) pathway. However, the activity level of the PI3K/Akt1 pathway was decreased in CHOP-treated CRL2631 cells. The selective PI3K inhibitor BKM120 significantly increased CHOP-induced apoptosis, but this effect was abolished by rPD-1 and aggravated by PD-L1 knockdown. In CHOP-treated PD-L1 knockdown cells, the increased apoptosis was markedly inhibited by the overexpression of constitutively active Akt1. Overall, the results demonstrate that the over-activated PD-1/PD-L1 axis is associated with chemotherapeutic resistance of DLBCL cells to the CHOP regimen, potentially through a PI3K-dependent mechanism.

The mechanisms of thrombogenicity in essential thrombocythemia (ET) are complex and not well defined. Our objective was to explore whether phosphatidylserine (PS) exposure on blood cells and endothelial cells (ECs) can account for the increased thrombosis and distinct thrombotic risks among mutational subtypes in ET. Using flow cytometry and confocal microscopy, we found that the levels of PS-exposing erythrocytes, platelets, leukocytes, and serum-cultured ECs were significantly higher in each ET group [JAK2, CALR, and triple-negative (TN) (all P < 0.001)] than those in controls. Among ET patients, those with JAK2 mutations showed higher levels of PS-positive erythrocytes, platelets, neutrophils, and serum-cultured ECs than TN patients or those with CALR mutations, which show similar levels. Coagulation function assays showed that higher levels of PS-positive blood cells and serum-cultured ECs led to markedly shortened coagulation time and dramatically increased levels of FXa, thrombin, and fibrin production. This procoagulant activity could be largely blocked by addition of lactadherin (approx. 70% inhibition). Confocal microscopy showed that the FVa/FXa complex and fibrin fibrils colocalized with PS on ET serum-cultured ECs. Additionally, we found a relationship between D-dimer, prothrombin fragment F1 + 2, and PS exposure. Our study reveals a previously unrecognized link between hypercoagulability and exposed PS on cells, which might also be associated with distinct thrombotic risks among mutational subtypes in ET. Thus, blocking PS-binding sites may represent a new therapeutic target for preventing thrombosis in ET.