rHuEPO enhances the production of plasminogen activator inhibitor-1 in cultured endothelial cells

Abstract

The direct effects of recombinant human erythropoietin(rHuEPO) on coagulation and fibrinolysis factors were evaluated in a cultured endothelial cell (EC) system. Confluent quiescent ECs were incubated with or without 5.0 U/ml rHuEPO for 1, 6, and 18 hours, and supernatant concentrations of plasminogen activator inhibitor-1 (PAI-1): antigen (Ag), tissue plasminogen activator and thrombomodulin, and supernatant activities of tissue factor pathway inhibitor and von Willebrand factor were measured. The results showed that only PAI-1 levels were increased by the presence of rHuEPO. In order to assess the effect of rHuEPO on PAI-1 production by EC more precisely, confluent ECs were incubated with various doses of rHuEPO (0, 1.0, 2.5, 5.0, 10.0 U/ml) for 1, 6, 12, and 18 hours, and PAI-1:Ag concentrations in the supernatants of media were measured. PAI-1:Ag in the supernatants were increased by the presence of rHuEPO at all incubation times (P < 0.01) and the increase in PAI-1:Ag was dependent on rHuEPO concentration. The increases in PAI-1:Ag by 5.0 U/ml rHuEPO were comparable to those by 0.1 U/ml tumor necrosis factor-alpha, 1.0 microgram/ml lipopolysaccharide, and 0.5 U/ml thrombin. The increase in PAI-1:Ag by rHuEPO was suppressed by pre-incubation with 10 micrograms/ml cycloheximide (P < 0.01) or 0.2 microgram/ml actinomycin D (P < 0.01). These results indicate that rHuEPO directly stimulates PAI-1 production in cultured EC via de novo protein and RNA syntheses.

Donor pretreatment with carbamylated erythropoietin in a brain death model reduces inflammation more effectively than erythropoietin while preserving renal function*

“…Finally, plasminogen activator inhibitor-1 gene expression was determined, because even a short time of exposure to EPO is known to increase the production of plasminogen activator inhibitor-1 in endothelial cells (32). In this study, EPO and cEPO administration had no effects on heme oxygenase-1 and plasminogen activator inhibitor-1 gene expression.…”

Comparison of carbamylated erythropoietin-FC fusion protein and recombinant human erythropoietin during porcine aortic balloon occlusion-induced spinal cord ischemia/reperfusion injury

“…Motor neuron function, however, did not recover, most likely due to the low dose of rhEPO administered and/or as a result of the marked tissue damage [4]. Moreover, Ehrenreich et al [5] recently reported a significantly higher overall death rate in rhEPO-treated patients with stroke, possibly as a result of the high number of patients undergoing systemic thrombolysis with recombinant tissue plasminogen activator: in vitro, a single rhEPO exposure enhances production of plasminogen activator inhibitor-1 [6].…”

From the Oxygen to the Organ Protection: Erythropoietin as Protagonist in Internal Medicine

“…The calcium protein channels can also become phosphorylated during EPO-R mediated activation [22]. As well as being expressed on the erythroid precursors [23], EPO-R is also expressed on the megakaryocytes [24], VSMC [25,26], endothelial cells [26][27][28], skeletal myoblasts [29], neuronal [30] and renal cells [31].…”