Erythropoietin and subarachnoid hemorrhage.

Cisplatin-induced peripheral neuropathy: neuroprotection by erythropoietin without affecting tumour growth

This study examined the dose-dependent efficacy of erythropoietin (EPO) for preventing and/or treating cisplatin (CDDP) induced peripheral neurotoxicity (CINP), and its influence on tumour treatment and growth. Rats received eight intraperitoneal (ip) injections of 2 mg/kg CDDP twice weekly. EPO co-administered (50 or 10 microg/kg ip, three times/week) had a dose-dependent effect, partially preventing CINP, but 0.5 microg/kg ip was not effective. The neuroprotective effect lasted at least 5 weeks after the last dose of EPO and CDDP. In addition, EPO (50 microg/kg ip three times/week) after the last injection of CDDP still induced a significant recovery of CINP. In a separate experiment in r…

Derivatives of Erythropoietin That Are Tissue Protective But Not Erythropoietic

Erythropoietin (EPO) is both hematopoietic and tissue protective, putatively through interaction with different receptors. We generated receptor subtype–selective ligands allowing the separation of EPO's bioactivities at the cellular level and in animals. Carbamylated EPO (CEPO) or certain EPO mutants did not bind to the classical EPO receptor (EPOR) and did not show any hematopoietic activity in human cell signaling assays or upon chronic dosing in different animal species. Nevertheless, CEPO and various nonhematopoietic mutants were cytoprotective in vitro and conferred neuroprotection against stroke, spinal cord compression, diabetic neuropathy, and experimental autoimmune encephalomyeli…

Erythropoietin mediates tissue protection through an erythropoietin and common beta-subunit heteroreceptor

The cytokine erythropoietin (Epo) is tissue-protective in preclinical models of ischemic, traumatic, toxic, and inflammatory injuries. We have recently characterized Epo derivatives that do not bind to the Epo receptor (EpoR) yet are tissue-protective. For example, carbamylated Epo (CEpo) does not stimulate erythropoiesis, yet it prevents tissue injury in a wide variety ofin vivoandin vitromodels. These observations suggest that another receptor is responsible for the tissue-protective actions of Epo. Notably, prior investigation suggests that EpoR physically interacts with the common β receptor (βcR), the signal-transducing subunit shared by the granulocyte-macrophage colony stimulating fa…

Erythropoietin and erythropoietin receptor expression after experimental spinal cord injury encourages therapy by exogenous erythropoietin

OBJECTIVE: Erythropoietin (EPO) is a pleiotropic cytokine originally identified for its role in erythropoiesis. Recent studies have demonstrated that EPO and its receptor (EPO-R) are expressed in the central nervous system, where EPO exerts neuroprotective functions. Because the expression of the EPO and EPO-R network is poorly investigated in the central nervous system, the aim of the present study was to investigate whether the resident EPO and EPO-R network is activated in the injured nervous system. METHODS: A well-standardized model of compressive spinal cord injury in rats was used. EPO and EPO-R expression was determined by immunohistochemical analysis at 8 hours and at 2, 8, and 14 …

Amelioration of spinal cord compressive injury by pharmacological preconditioning with erythropoietin and a nonerythropoietic erythropoietin derivative.

Object Spinal cord injury (SCI) is a devastating clinical syndrome for which no truly efficacious therapy has yet been identified. In preclinical studies, erythropoietin (EPO) and its nonerythropoietic derivatives asialoEPO and carbamylated EPO have markedly improved functional outcome when administered after compressive SCI. However, an optimum treatment paradigm is currently unknown. Because the uninjured spinal cord expresses a high density of EPO receptor (EPOR) in the basal state, signaling through these existing receptors in advance of injury (pharmacological preconditioning) might confer neuroprotection and therefore be potentially useful in situations of anticipated damage. Methods…

The Role of Erythropoietin in Neuroprotection: Therapeutic Perspectives

Nervous system diseases are very complex conditions comprising a large variety of local and systemic responses. Several therapeutic agents interfering with all or in part the biochemical steps that ultimately cause neuronal death have been demonstrated to be neuroprotective in preclinical models. However, all the agents so far investigated have inexorably failed in the phase III trials carried out. A large body of evidence suggests that the hormone erythropoietin (EPO), besides its well-known hematopoietic action, exerts beneficial effects in the central nervous system. EPO's effect has been assessed in several experimental models of brain and spinal cord injury thus becoming a serious cand…

The many faces of erythropoietin: from erythropoiesis to a rational neuroprotective strategy

It has been more than 10 years since the discovery that erythropoietin (EPO) and its receptor are expressed by the nervous system. In that brief time, a remarkable acceleration in understanding the...

Role of Erythropoietin in Cerebral Glioma: An Innovative Target in Neuro-Oncology

Background: Erythropoietin (EPO) is a cytokine primarily involved in the regulation of erythropoiesis. In response to hypoxia–ischemia, hypoxia-inducible factor 1 induces EPO production, which, in turn, inhibits apoptosis of erythroid progenitor cells. By the same mechanism and acting through other signaling pathways, EPO exerts neuroprotective effects. Increased resistance to hypoxia and decreased apoptosis are thought to be important mechanisms for tumor progression, including malignant glioma. Because recent studies have demonstrated that EPO and its receptor (EPOR) are expressed in several tumors and can promote tumor growth, in the present study, we investigated EPO and EPOR expression…

Neuroprotection by erythropoietin administration after experimental traumatic brain injury.

A large body of evidence indicates that the hormone erythropoietin (EPO) exerts beneficial effects in the central nervous system (CNS). To date, EPO's effect has been assessed in several experimental models of brain and spinal cord injury. This study was conducted to validate whether treatment with recombinant human EPO (rHuEPO) would limit the extent of injury following experimental TBI. Experimental TBI was induced in rats by a cryogenic injury model. rHuEPO or placebo was injected intraperitoneally immediately after the injury and then every 8 h until 2 or 14 days. Forty-eight hours after injury brain water content, an indicator of brain edema, was measured with the wet-dry method and bl…

Neuroprotective effect of erythropoietin and darbepoetin alfa after experimental intracerebral hemorrhage.

OBJECTIVE: Intracerebral hemorrhage (ICH) is a devastating clinical syndrome for which no truly efficacious therapy has yet been identified. In preclinical studies, erythropoietin (EPO) and its long-lasting analog, darbepoetin alfa, have been demonstrated to be neuroprotective in several models of neuronal insult. The objectives of this study were to analyze whether the systemic administration of recombinant human EPO (rHuEPO) and its long-lasting derivative darbepoetin alfa expedited functional recovery and brain damage in a rat model of ICH. METHODS: Experimental ICH was induced in rats by injecting autologous blood into the right striatum under stereotactic guidance. Subsequently, animal…

Mast cells in canine mammary gland tumour: number, distribution and EPOR positivity.

Erythropoietin (EPO)-mediated mitogenic and anti-apoptotic effects involve all the cells expressing functional receptors for EPO (EPOR), as demonstrated by in vitro and in vivo studies. EPO shows pleiotropic effects and acts as an endogenous mediator of adaptive tissue response to metabolic stress protecting tissues from different injuries. Recently, the EPO/EPOR complex has been identified in several neoplastic cell lines and solid tumours. In this study, the authors investigated the mast cells (MCs) number, distribution and their immunoreactivity for EPOR in normal, dysplastic and neoplastic canine mammary gland. The results showed that MCs were more numerous in displastic glands compared…

The erythropoietin and regenerative medicine: a lesson from fish

Background Erythropoietin (EPO), the main haematopoietic growth factor for the proliferation and differentiation of erythroid progenitor cells, is also known for its angiogenic and regenerative properties. Materials and methods In this study, we aimed to test the regenerative effects of EPO administration in an experimental model of Sea bass (Dicentrarchus labrax) subjected to amputation of the caudal fin. Results Erythropoietin-treated fishes (3000 UI of human recombinant EPO-alpha immediately after cutting and after 15 days) showed an increased growth rate of their fins compared with those untreated (ANOVA variance: P :0 AE01 vs. P :0 AE04). By analysing fin length at established times (1…