Effects of erythropoietin on reducing brain damage and improving functional outcome after traumatic brain injury in mice: Laboratory investigation
Department of Neurosurgery, Henry Ford Health System, Detroit, Michigan 48202, USA. Journal of Neurosurgery
(Impact Factor: 3.74).
09/2008; 109(3):510-521. DOI: 10.3171/JNS/2008/109/9/0510
This study was designed to investigate the beneficial effects of recombinant human erythropoietin (rhEPO) treatment of traumatic brain injury (TBI) in mice.
Adult male C57BL/6 mice were divided into 3 groups: 1) the saline group (TBI and saline [13 mice]); 2) EPO group (TBI and rhEPO ); and 3) sham group (sham and rhEPO ). Traumatic brain injury was induced by controlled cortical impact. Bromodeoxyuridine (100 mg/kg) was injected daily for 10 days, starting 1 day after injury, for labeling proliferating cells. Recombinant human erythropoietin was administered intraperitoneally at 6 hours and at 3 and 7 days post-TBI (5000 U/kg body weight, total dosage 15,000 U/kg). Neurological function was assessed using the Morris water maze and footfault tests. Animals were killed 35 days after injury, and brain sections were stained for immunohistochemical evaluation.
Traumatic brain injury caused tissue loss in the cortex and cell loss in the dentate gyrus (DG) as well as impairment of sensorimotor function (footfault testing) and spatial learning (Morris water maze). Traumatic brain injury alone stimulated cell proliferation and angiogenesis. Compared with saline treatment, rhEPO significantly reduced lesion volume in the cortex and cell loss in the DG after TBI and substantially improved recovery of sensorimotor function and spatial learning performance. It enhanced neurogenesis in the injured cortex and the DG.
Recombinant human erythropoietin initiated 6 hours post-TBI provided neuroprotection by decreasing lesion volume and cell loss as well as neurorestoration by enhancing neurogenesis, subsequently improving sensorimotor and spatial learning function. It is a promising neuroprotective and neurorestorative agent for TBI and warrants further investigation.
Available from: Ye Xiong
- "Although we did not use unbiased stereology to count cells in the present study, previous studies from us and other investigators have shown that the method used provides a meaningful comparison of differences in cell counting among groups after TBI and treatment , – and stroke . Cell counts were performed by observers blinded to the individual treatment status of the animals. "
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ABSTRACT: Traumatic brain injury (TBI) is a major cause of death and long-term disability worldwide. To date, there are no effective pharmacological treatments for TBI. Recombinant human tissue plasminogen activator (tPA) is the effective drug for the treatment of acute ischemic stroke. In addition to its thrombolytic effect, tPA is also involved in neuroplasticity in the central nervous system. However, tPA has potential adverse side effects when administered intravenously including brain edema and hemorrhage. Here we report that tPA, administered by intranasal delivery during the subacute phase after TBI, provides therapeutic benefit. Animals with TBI were treated intranasally with saline or tPA initiated 7 days after TBI. Compared with saline treatment, subacute intranasal tPA treatment significantly 1) improved cognitive (Morris water maze test) and sensorimotor (footfault and modified neurological severity score) functional recovery in rats after TBI, 2) reduced the cortical stimulation threshold evoking ipsilateral forelimb movement, 3) enhanced neurogenesis in the dentate gyrus and axonal sprouting of the corticospinal tract originating from the contralesional cortex into the denervated side of the cervical gray matter, and 4) increased the level of mature brain-derived neurotrophic factor. Our data suggest that subacute intranasal tPA treatment improves functional recovery and promotes brain neurogenesis and spinal cord axonal sprouting after TBI, which may be mediated, at least in part, by tPA/plasmin-dependent maturation of brain-derived neurotrophic factor.
Available from: pmr.lf1.cuni.cz
- "The naturally occurring cytokine erythropoietin (EPO) is widely known as a factor stimulating maturation, differentiation and survival of hematopoietic progenitor cells (Xiong et al., 2008). More-over EPO has been recently shown to be neuroprotective in the brain following a variety of injuries (cerebral ischemia, head injury, seizures, inflammation etc.) (Marti, 2004; Sargin et al., 2011). "
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ABSTRACT: We tested the influence of erythropoietin (EPO), a basic cytokine in erythropoiesis regulation, on the process of motor function and cognition after focal brain ischemia induced by a local application of endothelin. Endothelin-1 (ET-1) induced short lasting strong vasoconstriction, with described impact on the structure and on the function of neuronal cells. Neurological description of motor function and Morris water maze test (the swimming test is one of most widely used methods for studying cognitive functions in rodents) were used to study the process of learning and memory in three-month-old male albino Wistar rats (n=52). Both tests were performed one week before, and three weeks after ischemia induction (endothelin application on the cortex in the area of a. cerebri media dx.). Experimental group received i.p. injection of EPO (5,000 IU/kg body weight, 10 min before endothelin application). Control group of animals received one i.p. injection of saline at the dose of 1 ml/kg body weight at the same time. Only sham surgery was performed in the third group of animals. Rats with EPO pretreatment before the experimental lesion exhibited significantly better motor and cognitive function then those with saline injection. No significant changes in the motor and cognitive function were found in the third group of rats (sham operated controls).
Available from: Cristina morganti-kossmann
- "EPO has been shown to improve sensorimotor and cognitive deficits in rats after both CCI and cryogenic lesion injuries [22-24,41], with a therapeutic window of administration up to 24 h after injury reported to provide behavioural benefit . In keeping with the literature, in our study the injection of EPO at 1 and 24 h after TAI + Hx resulted in a sustained improvement in the Rotarod. "
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ABSTRACT: Diffuse axonal injury is a common consequence of traumatic brain injury (TBI) and often co-occurs with hypoxia, resulting in poor neurological outcome for which there is no current therapy. Here, we investigate the ability of the multifunctional compound erythropoietin (EPO) to provide neuroprotection when administered to rats after diffuse TBI alone or with post-traumatic hypoxia.
Sprague-Dawley rats were subjected to diffuse traumatic axonal injury (TAI) followed by 30 minutes of hypoxic (Hx, 12% O2) or normoxic ventilation, and were administered recombinant human EPO-alpha (5000 IU/kg) or saline at 1 and 24 hours post-injury. The parameters examined included: 1) behavioural and cognitive deficit using the Rotarod, open field and novel object recognition tests; 2) axonal pathology (NF-200); 3) callosal degradation (hematoxylin and eosin stain); 3) dendritic loss (MAP2); 4) expression and localisation of the EPO receptor (EpoR); 5) activation/infiltration of microglia/macrophages (CD68) and production of IL-1beta.
EPO significantly improved sensorimotor and cognitive recovery when administered to TAI rats with hypoxia (TAI + Hx). A single dose of EPO at 1 hour reduced axonal damage in the white matter of TAI + Hx rats at 1 day by 60% compared to vehicle. MAP2 was decreased in the lateral septal nucleus of TAI + Hx rats; however, EPO prevented this loss, and maintained MAP2 density over time. EPO administration elicited an early enhanced expression of EpoR 1 day after TAI + Hx compared with a 7-day peak in vehicle controls. Furthermore, EPO reduced IL-1beta to sham levels 2 hours after TAI + Hx, concomitant to a decrease in CD68 positive cells at 7 and 14 days.
When administered EPO, TAI + Hx rats had improved behavioural and cognitive performance, attenuated white matter damage, resolution of neuronal damage spanning from the axon to the dendrite, and suppressed neuroinflammation, alongside enhanced expression of EpoR. These data provide compelling evidence of EPO's neuroprotective capability. Few benefits were observed when EPO was administered to TAI rats without hypoxia, indicating that EPO's neuroprotective capacity is bolstered under hypoxic conditions, which may be an important consideration when EPO is employed for neuroprotection in the clinic.
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