Elevated Plasma P-Selectin Autoantibodies in Primary Sjögren Syndrome Patients with Thrombocytopenia.

BACKGROUND Primary Sjögren's syndrome (pSS) is one of the most common chronic systemic autoimmune diseases, and thrombocytopenia is one of the hematological manifestations of pSS. When platelet and endothelial cells are activated, P-selectin is expressed on the cell surface. This study aimed to investigate the role of P-selectin autoantibodies in the pathogenesis of thrombocytopenia in pSS. MATERIAL AND METHODS P-selectin autoantibodies were measured by enzyme-linked immunosorbent assay (ELISA) in 38 pSS patients without thrombocytopenia and 32 pSS patients with thrombocytopenia, 32 idiopathic thrombocytopenic purpura (ITP) patients, and 35 healthy controls. RESULTS The plasma P-selectin autoantibodies (A490) in ITP patients and pSS patients with/without thrombocytopenia were significantly higher than those in healthy controls, but there were no significant differences between ITP patients and pSS patients with thrombocytopenia. The positive rate of P-selectin autoantibodies in pSS patients with thrombocytopenia was significantly higher than that in ITP patients. The platelet count was lower in P-selectin autoantibodies-positive patients, while among pSS patients with thrombocytopenia, the platelet count was lower in P-selectin autoantibodies-positive patients than in P-selectin autoantibodies-negative patients. In ITP patients and pSS patients with thrombocytopenia, the platelet count was lower in P-selectin autoantibodies-positive patients. CONCLUSIONS Elevated plasma P-selectin autoantibodies may play a role in the pathogenesis of thrombocytopenia in pSS patients.

microRNA-21 promotes osteogenic differentiation of mesenchymal stem cells by the PI3K/ß-catenin pathway.

Osteogenesis of mesenchymal stem cells (MSCs) is essential for bone repair. Recently, microRNAs have been proven to play an important role in the regulation of MSC differentiation, including osteogenesis. Here, the function of microRNA-21 (miR-21) in the osteogenic differentiation of human umbilical cord mesenchymal stem cells (hUMSCs) was investigated. Briefly, the miR-21 mimics (m-miR-21) and the antisense miR-21 (as-miR-21) were transfected to hUMSCs, and the capacity of miR-21 for the osteogenic differentiation of hUMSCs was evaluated by the expression of osteogenic markers encoding alkaline phosphatase (ALP), runt-related gene-2 (RUNX-2) and osteocalcin (OCN), as well as by Alizarin red S staining. The results indicated that the overexpression of miR-21 elevated the expression level of the osteogenesis-related genes of hUMSCs. During this process, the PI3K-AKT signaling pathway activity had an increasing tendency responding to miR-21 up-regulation. This enhancement promoted the phosphorylation of GSK-3ß, leading to the stabilization and high concentration accumulation of ß-catenin in cytoplasm to activate the transcription of RUNX-2, and finally increased the osteogenesis of hUMSCs. This work demonstrated that miR-21 and its target PI3K-AKT-GSK3ß pathway played an important role in the osteogenic differentiation of hUMSCs by stabilizing ß-catenin.

A new D-dimer cutoff value to improve the exclusion of deep vein thrombosis in cancer patients.

OBJECTIVE: To find a more appropriate alternative to D-dimer cutoff value for the diagnosis of deep vein thrombosis (DVT) in cancer patients. METHODS: A total of 711 cancer patients with symptoms suspicious of DVT were included in the study. D-dimer levels were assessed using ELISA. All patients were subjected to imaging procedures. RESULTS: Among 711 patients with cancer, 466 (65.5%) were females and 245 (34.5%) were males, with an average age of 57.3 ± 13.23 years. The mean age in the DVT group was significantly higher than in the non-DVT group (P<0.05). The D-dimer levels of the DVT group were significantly higher than those of the non-DVT group (P<0.05). The incidence rate of DVT varied significantly according to cancer type (P<0.05). Increasing age and lung cancer were significantly correlated with D-dimer levels (P<0.05), and a one-year increase in age was associated with a 14.28 ng/ml increase in the D-dimer value. The optimal cutoff point for D-dimer was found to be 981 ng/ml, with a sensitivity of 86.4%, specificity of 79.4%, and accuracy of 82.6%. If the D-dimer cutoff point was set to 981 ng/ml, the specificity would increase from 61.8% to 85.5% without loss of sensitivity in patients aged 40 years or younger. In patients aged more than 40 years, the new cutoff almost doubled the specificity with slightly reduced sensitivity. CONCLUSION: In cancer patients, a new cutoff value of 981 ng/ml effectively improved the exclusion of DVT, especially for patients aged more than 40 years.

[Construction and expression of the recombinant plasmid containing BddhFVIII in HepG2 cells].

OBJECTIVE: To get stable cell line expressing B domain-deleted human FVIII (BDDhFVIII) by constructing the eukaryotic expression plasmid. METHODS: Eukaryotic expression plasmid containing BDDhFVIII was constructed and transfected into HepG2 cells via electroporation. The expression and purification of the target protein was detected by Western blot. RESULTS: Results of enzyme digestion and sequence analysis demonstrated that the gene of BDDhFVIII was correctly inserted into the eukaryotic expression vector pcDNA4/v5-his. Western blot confirmed the successful expression of BDDhFVIII at the protein levels in HepG2 cells. CONCLUSION: The constructed eukaryotic expression vector was able to generate high level expression of human FVIII in HepG2 cells, thus could construct human blood coagulation FVIII stable cell line successfully.