fondaparinux and Hypoxia

This in vitro study analyzed the impact of heparins on expression of chemokines in human endometrial adenocarcinoma cell lines.. Cell lines were incubated with unfractionated heparin (UFH), low molecular weight heparins (LMWH) and fondparinux under hypoxic and normoxic conditions. Chemokine (C-X-C motif) ligand 8 (CXCL8), CC-chemokine ligand 2 (CCL2) and CCL5 were detected by enzyme-linked immunosorbent assays and real-time reverse transcriptase-polymerase chain reaction and cell viability by fluorometric assay.. Different adenocarcinoma cell lines had distinct patterns of chemokine expression. UFH attenuated the secretion of CXCL8 and CCL2, and enhanced that of CCL5. The observed effects of heparin were in addition to the anti-coagulatory properties of heparin and dependent on molecular size and charge.. UFH has selective modulating effects on the secretion of CXCL8, CCL2 and CCL5 in different endometrial adenocarcinoma cell lines. Molecular size and charge are relevant for these observed effects. By influencing the expression of these inflammatory mediators and thereby affecting the tumour microenvironment, heparins and related agents might play an essential role in the development of new therapeutic strategies.

Topics: Adenocarcinoma; Cell Line, Tumor; Chemokine CCL2; Chemokine CCL5; Endometrial Neoplasms; Female; Fondaparinux; Gene Expression Regulation, Neoplastic; Heparin; Humans; Hypoxia; Interleukin-8; Polysaccharides

Thrombin is involved in mediating neuronal death in cerebral ischemia. We investigated its so far unknown mode of activation in ischemic neural tissue. We used an in vitro approach to distinguish the role of circulating coagulation factors from endogenous cerebral mechanisms. We modeled ischemic stroke by subjecting rat organotypic hippocampal slice cultures to 30-min oxygen (5%) and glucose (1 mmol/L) deprivation (OGD). Perinuclear activated factor X (FXa) immunoreactivity was observed in CA1 neurons after OGD. Selective FXa inhibition by fondaparinux during and after OGD significantly reduced neuronal death in the CA1 after 48 h. Thrombin enzyme activity was increased in the medium 24 h after OGD and this increase was prevented by fondaparinux suggesting that FXa catalyzes the conversion of prothrombin to thrombin in neural tissue after ischemia in vitro. Treatment with SCH79797, a selective antagonist of the thrombin receptor protease-activated receptor-1 (PAR-1), significantly decreased neuronal cell death indicating that thrombin signals ischemic damage via PAR-1. The c-Jun N-terminal kinase (JNK) pathway plays an important role in excitotoxicity and cerebral ischemia and we observed activation of the JNK substrate, c-Jun in our model. Both the FXa inhibitor, fondaparinux and the PAR-1 antagonist SCH79797, decreased the level of phospho-c-Jun Ser73. These results indicate that FXa activates thrombin in cerebral ischemia, which leads via PAR-1 to the activation of the JNK pathway resulting in neuronal death.

Topics: Animals; Animals, Newborn; Anticoagulants; Cell Death; Factor Xa; Fondaparinux; Gene Expression Regulation; Glucose; Hippocampus; Hypoxia; Ischemia; JNK Mitogen-Activated Protein Kinases; Organ Culture Techniques; Polysaccharides; Pyrroles; Quinazolines; Rats; Receptor, PAR-1; Serine; Signal Transduction; Thrombin