Erythropoietin and derivatives: Potential beneficial effects on the brain.

Erythropoietin (Epo), the main erythropoiesis-stimulating factor widely prescribed to overcome anemia, is also known nowadays for its cytoprotective action on non-hematopoietic tissues. In this context, Epo showed not only its ability to cross the blood-brain barrier, but also its expression in the brain of mammals. In clinical trials, recombinant Epo treatment has been shown to stimulate neurogenesis; improve cognition; and activate antiapoptotic, antioxidant, and anti-inflammatory signaling pathways.

Role of protein tyrosine phosphatase 1B (PTP1B) in the increased sensitivity of endothelial cells to a promigratory effect of erythropoietin in an inflammatory environment.

The proliferation and migration of endothelial cells are vascular events of inflammation, a process which can also potentiate the effects of promigratory factors. With the aim of investigating possible modifications in the activity of erythropoietin (Epo) in an inflammatory environment, we found that Epo at a non-promigratory concentration was capable of stimulating EA.hy926 endothelial cell migration when TNF-α was present.

Aquaporin-1 plays a key role in erythropoietin-induced endothelial cell migration.

Water influx through aquaporin-1 (AQP-1) has been linked to the ability of different cell types to migrate, and therefore plays an important part in processes like metastasis and angiogenesis. Since the erythroid growth factor erythropoietin (Epo) is now recognized as an angiogenesis promoter, we investigated the participation of AQP-1 as a downstream effector of this cytokine in the migration of endothelial cells. Inhibition of AQP-1 with either mercury ions (Hg) or a specific siRNA led to an impaired migration of EA.

[Anti-transglutaminase antibody in adults with celiac disease and their relation to the presence and duration of gluten-free diet].

Unlabelled: IgA anti-transglutaminase 2 (tTG2) antibody is a relevant marker in celiac disease. The utility of IgA anti-tTG2 determination is well established for the diagnosis, however their use in the follow-up of patients with gluten free diet (GFD) it is not fully established.

Objective: To determine IgA anti-tTG2 antibody levels in adult Paraguayan celiac disease patients and its relation to the presence and duration of the GFD.

Modification of erythropoietin structure by N-homocysteinylation affects its antiapoptotic and proliferative functions.

Many patients under therapy with recombinant human erythropoietin (rhuEPO) show resistance to the treatment, an effect likely associated with the accumulation of tissue factors, especially in renal and cardiovascular diseases. Hyperhomocysteinemia due to high serum levels of homocysteine has been suggested among the risk factors in those pathologies. Its main effect is the N-homocysteinylation of proteins due to the interaction between the highly reactive homocysteine thiolactone (HTL) and lysine residues.

Participation of membrane calcium channels in erythropoietin-induced endothelial cell migration.

Calcium (Ca) plays an important role in angiogenesis, as it activates the cell migration machinery. Different proangiogenic factors have been demonstrated to induce transient Ca increases in endothelial cells. This has raised interest in the contribution of Ca channels to cell migration, and in a possible use of channel-blocking compounds in angiogenesis-related pathologies.

Signaling pathways of cell proliferation are involved in the differential effect of erythropoietin and its carbamylated derivative.

It is now recognized that in addition to its activity upon erythroid progenitor cells, erythropoietin (Epo) is capable of stimulating survival of different non-erythroid cells. Since stimulation of erythropoiesis is unwanted for neuroprotection, Epo-like compounds with a more selective action are under investigation. Although the carbamylated derivative of erythropoietin (cEpo) has demonstrated non-hematopoietic tissue protection without erythropoietic effect, little is known about differential mechanisms between Epo and cEpo.

Protective action of erythropoietin on neuronal damage induced by activated microglia.

Inflammation is a physiological defense response, but may also represent a potential pathological process in neurological diseases. In this regard, microglia have a crucial role in either progression or amelioration of degenerative neuronal damage. Because of the role of hypoxia in pro-inflammatory mechanisms in the nervous system, and the potential anti-inflammatory protective effect of erythropoietin (Epo), we focused our investigation on the role of this factor on activation of microglia and neuroprotection.

A prospective study to assess the predictive value for hereditary spherocytosis using five laboratory tests (cryohemolysis test, eosin-5'-maleimide flow cytometry, osmotic fragility test, autohemolysis test, and SDS-PAGE) on 50 hereditary spherocytosis families in Argentina.

This prospective study was carried out to assess the usefulness of five laboratory tests in the diagnosis of hereditary spherocytosis (HS), based on the correlation of erythrocyte membrane protein defects with clinical and laboratory features, and also to determine the membrane protein deficiencies detected in Argentina. Of 116 patients and their family members tested, 62 of them were diagnosed to have HS. The specificity of cryohemolysis (CH) test was 95.

Calcium as a mediator between erythropoietin and protein tyrosine phosphatase 1B.

Erythropoietin (Epo) is crucial for promoting the survival, proliferation, and differentiation of mammalian erythroid progenitors. The central role played by tyrosine phosphorylation of erythropoietin receptor (EpoR) in Epo-cell activation has focused attention on protein tyrosine phosphatases (PTPs) as candidates implicated in the pathogenesis of the resistance to therapy with human recombinant Epo. Prototypic member of the PTP family is PTP1B, which has been implicated in the regulation of EpoR signaling pathways.

c-FLIP is involved in erythropoietin-mediated protection of erythroid-differentiated cells from TNF-alpha-induced apoptosis.

The TNF-alpha (tumour necrosis factor) affects a wide range of biological activities, such as cell proliferation and apoptosis. Cell life or death responses to this cytokine might depend on cell conditions. This study focused on the modulation of factors that would affect the sensitivity of erythroid-differentiated cells to TNF-alpha.