Neuroprotective effects of erythropoietin pretreatment in a rodent model of transient middle cerebral artery occlusion.

Abstract

UNLABELLED:

OBJECT.: There is an unmet clinical need to develop neuroprotective agents for neurosurgical and endovascular procedures that require transient cerebral artery occlusion. The aim in this study was to explore the effects of a single dose of recombinant human erythropoietin (rhEPO) before middle cerebral artery (MCA) occlusion in a focal cerebral ischemia/reperfusion model.

METHODS:

Twenty-eight adult male Wistar rats were subjected to right MCA occlusion via the intraluminal thread technique for 60 minutes under continuous cortical perfusion monitoring by laser Doppler flowmetry. Rats were divided into 2 groups: control and treatment. In the treated group, rhEPO (1000 IU/kg intravenously) was administered 10 minutes before the onset of the MCA ischemia. At 24-hour reperfusion, animals were examined for neurological deficits, blood samples were collected, and animals were killed. The following parameters were evaluated: brain infarct volume, ipsilateral hemispheric edema, neuron-specific enolase plasma levels, parenchyma histological features (H & E staining), Fluoro-Jade-positive neurons, p-Akt and total Akt expression by Western blot analysis, and p-Akt-positive nuclei by immunohistochemical investigation.

RESULTS:

Infarct volume and Fluoro-Jade staining of degenerating neurons in the infarct area did not vary between groups. The severity of neurological deficit (p < 0.001), amount of brain edema (78% reduction in treatment group, p < 0.001), and neuron-specific enolase plasma levels (p < 0.001) were reduced in the treatment group. Perivascular edema was histologically less marked in the treatment group. No variations in the expression or localization of p-Akt were seen.

CONCLUSIONS:

Administration of rhEPO before the onset of 60-minute transient MCA ischemia protected the brain from this insult. It is unlikely that rhEPO pretreatment leads to direct neuronal antiapoptotic effects, as supported by the lack of Akt activation, and its benefits are most probably related to an indirect effect on brain edema as a consequence of blood-brain barrier preservation. Although research on EPO derivatives is increasing, rhEPO acts through distinct neuroprotective pathways and its clinical safety profile is well known. Clinically available rhEPO is a potential therapy for prevention of neuronal injury induced by transitory artery occlusion during neurovascular procedures.

• Authors: Bernardo Oliveira Ratilal, Mariana Moreira Coutinho Arroja, Joao Pedro Fidalgo Rocha, Adelaide Maria Afonso Fernandes, Andreia Pereira Barateiro, Dora Maria Tuna Oliveira Brites, Rui Manuel Amaro Pinto, Bruno Miguel Nogueira Sepodes, Helder Dias Mota-Filipe
• Journal: Journal of neurosurgery (J Neurosurg) Vol. 121 Issue 1 Pg. 55-62 (Jul 2014) ISSN: 1933-0693 [Electronic] United States
• PMID: 24702327 (Publication Type: Journal Article)

Chemical References

• Neuroprotective Agents
• Erythropoietin
• Proto-Oncogene Proteins c-akt
• Phosphopyruvate Hydratase

Topics

• Animals
• Apoptosis (drug effects)
• Blood-Brain Barrier (drug effects, metabolism)
• Brain (drug effects, metabolism, pathology)
• Erythropoietin (pharmacology, therapeutic use)
• Infarction, Middle Cerebral Artery (drug therapy, metabolism, pathology)
• Ischemic Attack, Transient (drug therapy, metabolism, pathology)
• Male
• Neuroprotective Agents (pharmacology, therapeutic use)
• Phosphopyruvate Hydratase (blood)
• Phosphorylation (drug effects)
• Proto-Oncogene Proteins c-akt (metabolism)
• Rats
• Rats, Wistar