In JoVE (1)
Articles by Klytaimnistra Kiouptsi in JoVE
visualizing ल्युकोसैट रोलिंग और एन्जियोटेन्सिन द्वितीय में आसंजन-चूहों को भ्रमित: तकनीक और नुकसान Jeremy Lagrange1, Sabine Kossmann1,2, Klytaimnistra Kiouptsi1, Philip Wenzel1,2,3 1Center for Thrombosis and Hemostasis Mainz, University Medical Center Mainz, 2Center for Cardiology, University Medical Center Mainz, 3German Center for Cardiovascular Research (DZHK) इस पांडुलिपि ट्रांसजेनिक रिपोर्टर चूहों और एन्जियोटेन्सिन द्वितीय में फ्लोरोसेंट रंजक के विभिंन प्रशासन मार्गों के उपयोग का वर्णन-रक्त वाहिकाओं के intravital वीडियो माइक्रोस्कोपी का उपयोग प्रतिरक्षा कोशिकाओं के सक्रियकरण और उनके मूल्यांकन के लिए उच्च रक्तचाप प्रेरित रोल करने के लिए और endothelium का पालन करने की क्षमता ।
Other articles by Klytaimnistra Kiouptsi on PubMed
Hypoxia Impairs Agonist-induced Integrin αIIbβ3 Activation and Platelet Aggregation Scientific Reports. | Pubmed ID: 28790378 Under ischemic conditions, tissues are exposed to hypoxia. Although human physiology, to a certain extent, can adapt to hypoxic conditions, the impact of low oxygen levels on platelet function is unresolved. Therefore, we explored how reduction of atmospheric oxygen levels to 1% might affect agonist-induced aggregation and static adhesion of isolated human platelets. We uncovered that isolated, washed human platelets exposed to hypoxic conditions show reduced thrombin receptor-activating peptide-6 (TRAP-6) and convulxin-induced aggregation. Of note, this hypoxia-triggered effect was not observed in platelet-rich plasma. Independent of the agonist used (TRAP-6, ADP), activation of the platelet fibrinogen receptor integrin αIIbβ3 (GPIIbIIIa, CD41/CD61) was strongly reduced at 1% and 8% oxygen. The difference in agonist-induced integrin αIIbβ3 activation was apparent within 5 minutes of stimulation. Following hypoxia, re-oxygenation resulted in the recovery of integrin αIIbβ3 activation. Importantly, platelet secretion was not impaired by hypoxia. Static adhesion experiments revealed decreased platelet deposition to fibrinogen coatings, but not to collagen or vitronectin coatings, indicating that specifically the function of the integrin subunit αIIb is impaired by exposure of platelets to reduced oxygen levels. Our results reveal an unexpected effect of oxygen deprivation on platelet aggregation mediated by the fibrinogen receptor integrin αIIbβ3.
Mice Deficient in the Anti-haemophilic Coagulation Factor VIII Show Increased Von Willebrand Factor Plasma Levels PloS One. | Pubmed ID: 28837614 Von Willebrand factor (VWF) is the carrier protein of the anti-haemophilic Factor VIII (FVIII) in plasma. It has been reported that the infusion of FVIII concentrate in haemophilia A patients results in lowered VWF plasma levels. However, the impact of F8-deficiency on VWF plasma levels in F8-/y mice is unresolved. In order to avoid confounding variables, we back-crossed F8-deficient mice onto a pure C57BL/6J background and analysed VWF plasma concentrations relative to C57BL/6J WT (F8+/y) littermate controls. F8-/y mice showed strongly elevated VWF plasma concentrations and signs of hepatic inflammation, as indicated by increased TNF-α, CD45, and TLR4 transcripts and by elevated macrophage counts in the liver. Furthermore, immunohistochemistry showed that expression of VWF antigen was significantly enhanced in the hepatic endothelium of F8-/y mice, most likely resulting from increased macrophage recruitment. There were no signs of liver damage, as judged by glutamate-pyruvate-transaminase (GPT) and glutamate-oxalacetate-transaminase (GOT) in the plasma and no signs of systemic inflammation, as white blood cell subsets were unchanged. As expected, impaired haemostasis was reflected by joint bleeding, prolonged in vitro clotting time and decreased platelet-dependent thrombin generation. Our results point towards a novel role of FVIII, synthesized by the liver endothelium, in the control of hepatic low-grade inflammation and VWF plasma levels.