losartan-potassium and Spinal-Cord-Injuries

We performed a genome-wide analysis of long noncoding RNA (lncRNA) expression to identify novel targets for the further study of recombinant human erythropoietin (rhEPO) treatment of acute spinal cord injury (SCI) in rats.. Nine rats were randomly divided into 3 groups. No operation was performed in group 1. In groups 2 and 3, a laminectomy was performed at the 10th thoracic vertebra, and a contusion injury was induced by extradural application of an aneurysm clip. Group 1 rats did not receive any treatment, group 2 rats received a single intraperitoneal injection of normal saline, and group 3 rats received rhEPO. Three days after injury, spinal cord tissues were collected for RNA-Seq, microarray, differentially expressed genes (DEGs), Gene Ontology (GO) function enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, and protein-protein interaction (PPI) analyses.. Compared with group 1, 4,446 genes were found to be differentially expressed in group 2. Furthermore, 99 lncRNAs were found to be changed in the injury group. The data indicate that 2,471 mRNAs were upregulated, and 1,975 mRNAs were downregulated in group 2 as compared with group 1. In addition, 45 of the lncRNAs were upregulated, and the other 44 lncRNAs were downregulated. The top 5 upregulated and top 5 downregulated lncRNAs that were different between group 2 and group 1 are shown. The top 5 downregulated and the top 5 upregulated lncRNAs that were different between group 3 and group 2 are shown.. RhEPO treatment alters the expression profiles of the differentially expressed lncRNAs and genes beneficial to the development of new treatments.

Topics: Animals; Computational Biology; Erythropoietin; Gene Expression Profiling; Humans; Rats; RNA, Long Noncoding; Spinal Cord Injuries

Spinal cord injury (SCI) is one of the most destructive traumatic diseases in human beings. The balance of inflammation in the microenvironment is crucial to the repair process of spinal cord injury. Inflammatory cytokines are direct mediators of local lesion inflammation and affect the prognosis of spinal cord injury to varying degrees. In spinal cord injury models, some inflammatory cytokines are beneficial for spinal cord repair, while others are harmful. A large number of animal studies have shown that local targeted administration can effectively regulate the secretion and delivery of inflammatory cytokines and promote the repair of spinal cord injury. In addition, many clinical studies have shown that drugs can promote the repair of spinal cord injury by regulating the content of inflammatory cytokines. However, topical administration affects only a small portion of inflammatory cytokines. In addition, different individuals have different inflammatory cytokine profiles during spinal cord injury. Therefore, future research should aim to develop a personalized local delivery therapeutic cocktail strategy to effectively and accurately regulate inflammation and obtain substantial functional recovery from spinal cord injury.

Topics: Animals; Chemokine CXCL12; Cytokines; Disease Models, Animal; Erythropoietin; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Inflammation; Interferon-beta; Interleukin-1; Interleukin-10; Interleukin-33; Mice; Neuroinflammatory Diseases; Neuroprotective Agents; Recovery of Function; Spinal Cord; Spinal Cord Injuries

Spinal cord injury (SCI) is a debilitating neurologic condition with tremendous socioeconomic impact on affected individuals and the health care system. The treatment of SCI principally includes surgical treatment and marginal pharmacologic and rehabilitation therapies targeting secondary events with minor clinical improvements. This unsuccessful result mainly reflects the complexity of SCI pathophysiology and the diverse biochemical and physiologic changes that occur in the injured spinal cord. Once the nervous system is injured, cascades of cellular and molecular events are triggered at varying times. Although the cascade of tissue reactions and cell injury develops over a period of days or weeks, the most extensive cell death in SCI occurs within hours of trauma. This situation suggests that early intervention is likely to be the most promising approach to rescue the cord from further and irreversible cell damage. Over the past decades, a wealth of research has been conducted in preclinical and clinical studies with the hope to find new therapeutic strategies. Researchers have identified several targets for the development of potential therapeutic interventions (e.g., neuroprotection, replacement of cells lost, removal of inhibitory molecules, regeneration, and rehabilitation strategies to induce neuroplasticity). Most of these treatments have passed preclinical and initial clinical evaluations but have failed to be strongly conclusive in the clinical setting. This narrative review provides an update of the many therapeutic interventions after SCI, with an emphasis on the underlying pathophysiologic mechanisms.

Topics: Decompression, Surgical; Erythropoietin; Fibroblast Growth Factors; Glyburide; Granulocyte Colony-Stimulating Factor; Hepatocyte Growth Factor; Humans; Hypoglycemic Agents; Intercellular Signaling Peptides and Proteins; Mesenchymal Stem Cell Transplantation; Neural Stem Cells; Neurological Rehabilitation; Neuronal Plasticity; Neuroprotection; Regenerative Medicine; Schwann Cells; Spinal Cord Injuries; Stem Cell Transplantation

Spinal Cord Injury (SCI) is a complex process which leads to destruction of neuronal tissue and also vascular structure. After SCI many potentially toxic substances are activated and released into the injury site causing secondary degeneration. Erythropoietin (EPO) is a possible therapeutic strategy to treat SCI. Over the last decade attention has been focused on the molecular mechanisms underlying its neuroprotective effects. A major concern expressed by clinicians is that besides its protective effects, EPO also demonstrates hematopoietic activity and increases the risk for thrombosis after the administration of multiple doses of this glycoprotein. Recently, tissue protective functions of EPO have been separated from its hematopoietic actions leading to the development of EPO derivatives and mimetics. Neuroscientists are focusing on recombinant human EPO (rhEPO) and its non-erythropoietic derivatives, investigating their anti-apoptotic potential and anti-inflammatory function as well as their role in restoring vascular integrity. Carbamylated erythropoietin (CEPO) and asialo erythropoietin (AsialoEPO) are structural derivatives of EPO that have no effect on erythrocyte mass whereas they retained its neuroprotective effects. In this review article, we provide a short overview of the animal studies on rhEPO and its derivatives in experimental models of SCI. Both the efficacy and the safety profile of EPO-structural and functional variants are still to be demonstrated in patients. Further clinical studies should reveal whether derivatives and variants of erythropoietin provide any benefits over the use of rhEPO in the treatment of spinal cord injury observed in the experimental studies.

Topics: Erythropoietin; Humans; Neuroprotective Agents; Recombinant Proteins; Spinal Cord Injuries

Spinal cord injury (SCI) is a devastating condition for individual patients and costly for health care systems requiring significant long-term expenditures. Cytokine erythropoietin (EPO) is a glycoprotein mediating cytoprotection in a variety of tissues, including spinal cord, through activation of multiple signaling pathways. It has been reported that EPO exerts its beneficial effects by apoptosis blockage, reduction of inflammation, and restoration of vascular integrity. Neuronal regeneration has been also suggested. In the present review, the pathophysiology of SCI and the properties of endogenous or exogenously administered EPO are briefly described. Moreover, an attempt to present the current traumatic, ischemic and inflammatory animal models that mimic SCI is made. Currently, a clearly effective pharmacological treatment is lacking. It is highlighted that administration of EPO or other recently generated EPO analogues such as asialo-EPO and carbamylated-EPO demonstrate exceptional preclinical characteristics, rendering the evaluation of these tissue-protective agents imperative in human clinical trials.

Topics: Animals; Clinical Trials as Topic; Disease Models, Animal; Drug Evaluation, Preclinical; Erythropoietin; Humans; Myelitis; Nerve Degeneration; Neuroprotective Agents; Spinal Cord; Spinal Cord Injuries

The growth factor erythropoietin (EPO) and erythropoietin receptors (EPOR) are expressed in the nervous system. Neuronal expression of EPO and EPOR peaks during brain development and is upregulated in the adult brain after injury. Peripherally administered EPO, and at least some of its variants, cross the blood-brain barrier, stimulate neurogenesis, neuronal differentiation, and activate brain neurotrophic, anti-apoptotic, anti-oxidant and anti-inflammatory signaling. These mechanisms underlie their tissue protective effects in nervous system disorders. As the tissue protective functions of EPO can be separated from its stimulatory action on hematopoiesis, novel EPO derivatives and mimetics, such as asialo-EPO and carbamoylated EPO have been developed. While the therapeutic potential of the novel EPO derivatives continues to be characterized in preclinical studies, the experimental findings in support for the use of recombinant human (rh)EPO in human brain disease have already been translated to clinical studies in acute ischemic stroke, chronic schizophrenia, and chronic progressive multiple sclerosis. In this review article, we assess the studies on EPO and, in particular, on its structural or functional variants in experimental models of nervous system disorders, and we provide a short overview of the completed and ongoing clinical studies testing EPO as neuroprotective/neuroregenerative treatment option in neuropsychiatric disease.

Topics: Animals; Brain Diseases; Erythropoietin; Humans; Nervous System; Neurodegenerative Diseases; Neurons; Neuroprotective Agents; Peripheral Nerves; Receptors, Erythropoietin; Retinal Diseases; Schizophrenia; Signal Transduction; Spinal Cord Injuries; Stroke

Carbamylated erythropoietin (CEPO) is a modified erythropoietin molecule not affecting hematocrit. It is a potentially important pharmacological agent that may be applied to the treatment of several diseases affecting central and peripheral system neurons.. Carbamylated erythropoietin is a prime candidate for development because of its potent cell survival and function enhancing effects. This article reviews the preclinical development profile of CEPO in animal models to determine whether further clinical development is justified.. The review spans a detailed analysis of patents and scientific publications related to CEPO in animal models.. Use of CEPO in treating diseases such as stroke and traumatic brain and spinal cord injuries is important because these conditions affect millions of patients every year. Extensive preclinical studies support further clinical studies of CEPO for acute ischemic stroke. However, further studies are required for testing CEPO in patients with many other indications.

Topics: Animals; Brain Injuries; Clinical Trials as Topic; Diabetic Neuropathies; Disease Models, Animal; Erythropoietin; Humans; Motor Neuron Disease; Nervous System Diseases; Spinal Cord Injuries; Stroke; Treatment Outcome

Spinal cord injury leads to a devastating cascade of secondary complications that eventually results in the formation of scar tissue many times the size of the original insult. Inflammation plays a very important role towards the development of such scar, but paradoxically, at the same time it has neuroprotective properties. Only recently have we understood enough about the relevant events to make the repair of injured spinal cords a reachable goal. Over the past decade, researchers have designed and tested numerous innovative therapeutic strategies, and many of such involve manipulation of the immune response. Interestingly, both immuno-stimulatory and immuno-suppressive interventions have shown positive results, which include the prevention of further tissue damage, prevention of secondary cell death and axonal degeneration, promotion of remyelination, stimulation of axonal regeneration, and facilitation of sensorimotor function recovery.

Topics: Erythropoietin; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Inflammation; Lymphocyte Activation; Macrophage Activation; Minocycline; Neutrophils; Peptides; rho-Associated Kinases; Spinal Cord Injuries; T-Lymphocytes

Erythropoietin (EPO) is an endogenous cytokine with antiapoptotic, antiinflammatory, and neurotrophic properties. Apart from being produced by the kidney, liver, and spleen in response to hypoxia, EPO is highly expressed in the brain during development and after neuropathological insults. The observation that receptors for EPO are present on brain capillaries and glial capillary end-feet has suggested that circulating (plasma) EPO may be transferred into the brain. This review summarizes the increasing number of studies indicating that peripherally administered recombinant human (rHu) EPO crosses the blood-brain barrier. Moreover, several of these studies have shown that peripherally administered rHuEPO can protect against the damage caused by a diversity of neuropathological conditions such as (a) stroke, (b) head and spinal cord trauma, (c) inflammatory and demyelinating conditions, (d) toxin-induced epileptic seizures, and (e) retinal ischemia. While all these studies are based on experiments in animal models, the effectiveness of rHuEPO in ischemic stroke in human patients has recently been suggested in a proof-of-concept trial, which is also discussed.

Topics: Animals; Blood-Brain Barrier; Brain Injuries; Controlled Clinical Trials as Topic; Cross-Sectional Studies; Demyelinating Diseases; Disease Models, Animal; Erythropoietin; Evidence-Based Medicine; Female; Humans; Injections, Intramuscular; Injections, Intraperitoneal; Male; Mice; Neuroprotective Agents; Rabbits; Rats; Recombinant Proteins; Sensitivity and Specificity; Spinal Cord Injuries; Stroke; Treatment Outcome

To evaluate the functional and immunohistochemical effects of ganglioside GM1 and erythropoietin following experimental spinal cord injury.. Thirty-two male BALB/c mice were subjected to experimental spinal cord injury using the NYU Impactor device and were randomly divided into the following groups: GM1 group, receiving standard ganglioside GM1 (30 mg/kg); erythropoietin group, receiving erythropoietin (1000 IU/kg); combination group, receiving both drugs; and control group, receiving saline (0.9%). Animals were evaluated according to the Basso Mouse Scale (BMS) and Hindlimb Mouse Function Score (MFS). After euthanasia, the immunohistochemistry of the medullary tissue of mice was analyzed. All animals received intraperitoneal treatment.. The GM1 group had higher BMS and MFS scores at the end of the experiment when compared to all other groups. The combination group had higher BMS and MFS scores than the erythropoietin and control groups. The erythropoietin group had higher BMS and MFS scores than the control group. Immunohistochemical tissue analysis showed a significant difference among groups. There was a significant increase in myelinated axons and in the myelinated axon length in the erythropoietin group when compared to the other intervention groups (p < 0.01).. Erythropoietin and GM1 have therapeutic effects on axonal regeneration in mice subjected to experimental spinal cord injury, and administration of GM1 alone had the highest scores on the BMS and MFS scales.

Topics: Animals; Disease Models, Animal; Epoetin Alfa; Erythropoietin; G(M1) Ganglioside; Injections, Intraperitoneal; Male; Mice; Spinal Cord; Spinal Cord Injuries

Pilot double-blinded randomized controlled trial.. To investigate the additive effect of recombinant human erythropoietin (rhEPO) on functional outcome and disability in patients with traumatic cervical spinal cord injury (TCSCI).. University-affiliated hospital in Mashhad, Iran.. Patients with acute TCSCI admitted within 8 h after injury were randomly assigned to receive only methylprednisolone (M group) or rhEPO 500 IU/mL plus methylprednisolone (M + E group). All the patients underwent surgery within the next several days. Neurological function was assessed on admission, and at 6th and 12th months after the injury according to the sphincter function and American spinal cord injury association (ASIA) scale.. Overall, 54 patients (mean age: 39.7 ± 13.3 years) including 46 (85%) males were studied in two groups of 27. The likelihood of developing adverse neurological outcomes (ASIA impairment score of A compared to D or E) was not significantly different between the groups after 6 (OR = 0.39, 95% CI = 0.03-4.80, P = 0.46) and 12 months (OR = 0.83, 95% CI = 0.11-6.11, P = 0.86). The groups also showed no significant difference in 1-year mortality (OR = 0.83, 95% CI = 0.25-2.74, P = 0.76).. It is not clear whether combination therapy with erythropoietin compared to methylprednisolone alone improves neurological functions of patients with TCSCI. Our study provides interim data to guide future larger definitive trials.

Topics: Adult; Cervical Cord; Erythropoietin; Female; Humans; Male; Methylprednisolone; Pilot Projects; Spinal Cord Injuries

The only available treatment of traumatic spinal cord injury (TSCI) is high-dose methylprednisolone (MP) administered acutely after injury. However, as the efficacy of MP is controversial, we assessed the superiority of erythropoietin (EPO) versus MP in improving clinical outcome of acute TSCI. Patients aged 18 to 65 years after C5-T12 injury, and grade A or B of the ASIA Impairment Scale (AIS), admitted within 8 h, hemodynamically stable, were randomized to MP according to the NASCIS III protocol or EPO iv (500 UI/kg, repeated at 24 and 48 h). Patients were assessed by an investigator blind to treatment assignment at baseline and at day 3, 7, 14, 30, 60 and 90. Primary end point: number of responders (reduction of at least one AIS grade). Secondary end points: treatment safety and the effects of drugs on a number of disability measures. Frequentistic and post hoc Bayesian analyses were performed. Eight patients were randomized to MP and 11 to EPO. Three patients (27.3 %) on EPO and no patients on MP reached the primary end point (p = 0.17). No significant differences were found for the other disability measures. No adverse events or serious adverse events were reported in both groups. The Bayesian analysis detected a 91.8 % chance of achieving higher success rates on the primary end point with EPO in the intention-to-treat population with a 95 % chance the difference between EPO and MP falling in the range (-0.10, 0.51) and a median value of 0.2. The results of Bayesian analysis favored the experimental treatment.

Topics: Adolescent; Adult; Aged; Bayes Theorem; Cervical Vertebrae; Computer Simulation; Erythropoietin; Female; Humans; Italy; Male; Methylprednisolone; Middle Aged; Neuroprotective Agents; Single-Blind Method; Spinal Cord Injuries; Thoracic Vertebrae; Time Factors; Treatment Outcome; Young Adult

Recent studies in animal models indicate that recombinant human erythropoietin (rhEPO) is very effective in enhancing neurological recovery after spinal cord injury (SCI). We aimed to evaluate the effect of rhEPO plus methylprednisolone sodium succinate (MPSS) compared to MPSS alone to improve neurological function of patients after SCI in a randomized clinical trial. During a 15-month period 30 patients presenting to emergency departments of two university affiliated hospitals within less than 6 hours after acute SCI were randomized to two groups. Both groups received MPSS 30 mg/kg initially and 5.4 mg/kg every hour till 23 hours if admitted within 3 hours and till 47 hours if recruited within 3-6 hours after injury. Group EPO also received 500 unit/kg rhEPO on admission and another 500 unit/kg 24 hours later instead of placebo in group MPSS. Neurologic evaluation was performed on admission, 24, 48, 72 hours and one and 6 months later. Range of patients' age was 18-65 years. There was no significant difference between patients receiving two types of treatment in neurological exam on admission (P=0.125), 24 hours after admission (P=0.108) and 48 hours after admission (P=0.085). However, one week (P=0.046), one month (P=0.021) and six months (P=0.018) after admission these differences were significant. MPSS plus rhEPO started within 6 hours after acute spinal injury may be more effective than MPSS plus placebo in improvement of neurologic dysfunction. More studies with larger sample sizes are warranted.

Topics: Acute Disease; Adolescent; Adult; Aged; Epoetin Alfa; Erythropoietin; Female; Hematinics; Humans; Male; Methylprednisolone; Middle Aged; Neuroprotective Agents; Recombinant Proteins; Spinal Cord Injuries; Treatment Outcome

Adalimumab (ADM), a humanized antibody against tumour necrosis factor (TNF), is widely applied in treating inflammatory and autoimmune diseases, but its usage in spinal cord injury (SCI) is rarely reported. Hence, this study aimed to explore the effect of ADM with or without erythropoietin (EPO) on microglial polarization, neuroinflammation, neural apoptosis, and functional recovery in SCI.. Primary microglia were stimulated with lipopolysaccharide (LPS) and then treated with ADM, EPO, or ADM combined with EPO. Then, primary neurons were incubated in the microglial culture medium. SCI rats were established and then treated with ADM, EPO or ADM combined with EPO.. ADM suppressed LPS-induced microglial M1 polarization, as reflected by downregulated iNOS and CD86 expression, and neuroinflammation, as reflected by decreased TNF-α, IL-1β, and IL-6 expression, in a dose-dependent manner. Moreover, ADM inhibited microglia-induced neural apoptosis, as reflected by TUNEL assay results and the expression of apoptotic markers (C-Caspase3 and Bcl2), in a dose-dependent manner. EPO monotherapy displayed an effect similar to that of ADM monotherapy. Furthermore, ADM combined with EPO therapy exhibited greater effects than either monotherapy in terms of inhibiting microglial M1 polarization, neuroinflammation, and neural apoptosis. In vivo experiments confirmed the findings of the in vitro experiments and showed that ADM combined with EPO improved SCI functional recovery and neural injury compared with monotherapy.. ADM combined with EPO improves recovery from SCI by suppressing microglial M1 polarization-mediated neural inflammation and apoptosis.

Topics: Adalimumab; Animals; Apoptosis; Erythropoietin; Inflammation; Lipopolysaccharides; Microglia; Neuroinflammatory Diseases; Rats; Spinal Cord; Spinal Cord Injuries; Tumor Necrosis Factor-alpha

Spinal strokes may be associated with tremendous spinal cord injury. Erythropoietin (EPO) improves the neurological outcome of animals after spinal cord ischemia (SCI) and its effects on ischemia-induced endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) are considered possible molecular mechanisms. Furthermore, sphingosin-1-phosphate (S1P) is suggested to correlate with SCI. In this study, the effect of recombinant human EPO (rhEPO) and carbamylated EPO (cEPO-Fc) on the outcome of mice after SCI and a prognostic value of S1P were investigated. SCI was induced in 12-month-old male mice by thoracic aortal cross-clamping after administration of rhEPO, cEPO-Fc, or a control. The locomotory behavior of mice was evaluated by the Basso mouse scale and S1P serum levels were measured by liquid chromatography-tandem mass spectrometry. The spinal cord was examined histologically and the expressions of key UPR proteins (ATF6, PERK, and IRE1a, caspase-12) were analyzed utilizing immunohistochemistry and real-time quantitative polymerase chain reaction. RhEPO and cEPO-Fc significantly improved outcomes after SCI. The expression of caspase-12 significantly increased in the control group within the first 24 h of reperfusion. Animals with better locomotory behavior had significantly higher serum levels of S1P. Our data indicate that rhEPO and cEPO-Fc have protective effects on the clinical outcome and neuronal tissue of mice after SCI and that the ER is involved in the molecular mechanisms. Moreover, serum S1P may predict the severity of impairment after SCI.

Topics: Animals; Caspase 12; Epoetin Alfa; Erythropoietin; Humans; Infant; Lysophospholipids; Male; Mice; Neuroprotective Agents; Recombinant Proteins; Sphingosine; Spinal Cord Injuries; Spinal Cord Ischemia; Stroke

Studies have found that molecular targets that regulate tissue development are also involved in regulating tissue regeneration. Erythropoietin-producing hepatocyte A4 (EphA4) not only plays a guiding role in neurite outgrowth during the development of the central nervous system (CNS) but also induces injured axon retraction and inhibits axon regeneration after spinal cord injury (SCI). EphA4 targets several ephrin ligands (including ephrin-A and ephrin-B) and is involved in cortical cell migration, axon guidance, synapse formation and astrocyte function. However, how EphA4 affects axon regeneration after SCI remains unclear. This study focuses on the effect and mechanism of EphA4-regulated astrocyte function in neuronal regeneration after SCI. Our research found that EphA4 expression increased significantly after SCI and peaked at 3 days post-injury; accordingly, we identified the cellular localization of EphA4 and ephrin-B ligands in neurons and astrocytes after SCI. EphA4 was mainly expressed on the surface of neurons, ephrin-B1 and ephrin-B3 were mainly localized on astrocytes, and ephrin-B2 was distributed on both neurons and astrocytes. To further elucidate the effect of EphA4 on astrocyte function after SCI, we detected the related cytokines secreted by astrocytes in vivo. We found that the levels of neurotrophic factors including nerve growth factor (NGF) and basic fibroblast growth factor (bFGF) increased significantly after SCI (NGF peaked at 3 days and bFGF peaked at 7 days); the expression of laminin and fibronectin increased gradually after SCI; the expression of inflammatory factors [interleukin (IL)-1β and IL-6] increased significantly from 4 h to 7 days after SCI; and the levels of glial fibrillary acidic protein (GFAP), a marker of astrocyte activation, and chondroitin sulphate proteoglycan (CSPG), the main component of glial scars, both peaked at 7 days after SCI. Using a damaged astrocyte model in vitro, we similarly found that the levels of related cytokines increased after injury. Consequently, we observed the effect of damaged astrocytes on neurite outgrowth and regeneration, and the results showed that damaged astrocytes hindered neurite outgrowth and regeneration; however, the inhibitory effect of injured astrocytes on neurite regeneration was reduced following ephrin-B receptor knockdown or inflammatory inhibition at 24 h after astrocyte injury. Our results showed that EphA4 regulates the secretion of neurotrophic factors, adhesion

Topics: Astrocytes; Axons; Cytokines; Ephrins; Erythropoietin; Gliosis; Hepatocytes; Humans; Ligands; Nerve Growth Factor; Nerve Regeneration; Neurons; Spinal Cord; Spinal Cord Injuries

Spinal cord injury (SCI) is a major disabling disorder for which no effective treatment has yet been found. Regenerative incapability of neuronal cells as well as the secondary mechanisms of injury are the major reasons behind this clinical frustration. Thus, here we fabricated an erythropoietin-chitosan/alginate (EPO-CH/AL) hydrogel and investigated its local therapeutic effects on the apoptotic and inflammatory indices of SCI secondary injury.. EPO-CH/AL hydrogels were fabricated by the ionic gelation method, and they were characterized using SEM and FTIR. In vitro drug release profile of EPO-CH/AL hydrogels was evaluated by UV-vis spectroscopy. Experimental SCI was inflicted in rats which were then treated with CH/AL hydrogels containing different doses of EPO (1000, 5000 and 10,000 IU/kg). The relative expression of Bax and Bcl2 (apoptosis index) and active and inactive forms of NF-κB (inflammation index) were assessed using western blot. Total serum levels of TNF-α were also assessed with ELISA, and histopathological and immunohistochemistry studies were carried out to check the overall changes in the injured tissues.. In vitro drug release test indicated that the EPO-CH/AL hydrogels had a sustained- and controlled-release profile for EPO under these conditions. All the fabricated hydrogels dramatically reduced the elevated inflammation and apoptosis indices of the SCI-inflicted rats (p ≤ 0.05). Nevertheless, only EPO-CH/AL hydrogel (1000 IU/kg EPO) significantly improved the tissue repair and histopathological appearance of the spinal cord at the sites of injury.. Based on our findings, EPO-CH/AL hydrogel (1000 IU/kg EPO) can effectively improve experimental SCI in rats via inhibiting apoptosis and inflammation. Further studies are warranted to elucidate the contributing role of the scaffold in the observed effects.

Topics: Alginates; Animals; bcl-2-Associated X Protein; Cell Line; Cell Survival; Chitosan; Disease Models, Animal; Dose-Response Relationship, Drug; Erythropoietin; Gene Expression Regulation; Humans; Hydrogels; Male; NF-kappa B; Proto-Oncogene Proteins c-bcl-2; Random Allocation; Rats; Spinal Cord Injuries; Tumor Necrosis Factor-alpha

Physical therapy with whole body vibration (WBV) following compressive spinal cord injury (SCI) in rats restores density of perisomatic synapses, improves body weight support and leads to a better bladder function. The purpose of the study was to determine whether the combined treatment with WBV plus erythropoietin (EPO) would further improve motor, sensory and vegetative functions after SCI in rats.. Severe compressive SCI at low thoracic level was followed by a single i.p. injection of 2,5μg (250 IU) human recombinant EPO. Physical therapy with WBV started on 14th day after injury and continued over a 12-week post injury period. Locomotor recovery, sensitivity tests and urinary bladder scores were analysed at 1, 3, 6, 9, and 12 weeks after SCI. The closing morphological measurements included lesion volume and numbers of axons in the preserved perilesional neural tissue bridges (PNTB).. Assessment of motor performance sensitivity and bladder function revealed no significant effects of EPO when compared to the control treatments. EPO treatment neither reduced the lesion volume, nor increased the number of axons in PNTB.. The combination of WBV + EPO exerts no positive effects on hind limbs motor performance and bladder function after compressive SCI in rats.

Topics: Animals; Erythropoietin; Physical Therapy Modalities; Rats; Recovery of Function; Spinal Cord Compression; Spinal Cord Injuries; Vibration

Traumatic spinal cord injury (SCI) is a devastating neurological disease for which an accurate, cost-effective prediction of motor function recovery is in pressing need. A plethora of neurochemical changes involved in the pathophysiological process of SCI may serve as a new source of biomarkers for patient outcomes. Five dogs were included in this study. We characterized the plasma cytokine profiles in acute phase (0, 1, and 3 days after SCI) and subacute phase (7, 14, and 21 days after SCI) with microarray analysis. The motor function recovery following SCI was monitored by Olby scores. The expression level of differentially expressed proteins (DEPs) was measured with enzyme-linked immunosorbent assay (ELISA). Then, correlations with the Olby scores and receiver operating characteristic curve (ROC) analysis were performed. We identified 12 DEPs including 10 pro-inflammatory and 2 anti-inflammatory cytokines during the 21-day study period. Among those, the expression levels of erythropoietin (EPO), IL-17A, and IFNγ significantly correlated with the Olby scores with R

Topics: Animals; Biomarkers; Dogs; Erythropoietin; Interferon-gamma; Interleukin-17; Movement; Spinal Cord Injuries

The objective of this study was to explore the neuroprotective molecular mechanisms of erythropoietin (EPO) in rats following spinal cord injury (SCI). First, a standard SCI model was established. After drug or saline treatment was administered, locomotor function was evaluated in rats using the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale. H&E, Nissl, and TUNEL staining were performed to assess the ratio of cavities, number of motor neurons, and apoptotic cells in the damaged area. The relative protein and mRNA expressions were examined using western blot and qRT-PCR analyses, and the inflammatory markers, axon special protein, and neuromuscular junctions (NMJs) were detected by immunofluorescence. Both doses of EPO notably improved locomotor function, but high-dose EPO was more effective than low-dose EPO. Moreover, EPO reduced the cavity ratio, cell apoptosis, and motor neuron loss in the damaged area, but enhanced the autophagy level and extracellular-regulated protein kinase (ERK) activity. Treatment with an ERK inhibitor significantly prevented the effect of EPO on SCI, and an activator mimicked the benefits of EPO. Further investigation revealed that EPO promoted SCI-induced autophagy via the ERK signaling pathway. EPO activates autophagy to promote locomotor function recovery in rats with SCI via the ERK signaling pathway.

Topics: Animals; Anti-Inflammatory Agents; Apoptosis; Autophagy; Cell Survival; Down-Regulation; Erythropoietin; Inflammation; MAP Kinase Signaling System; Motor Neurons; Neuroprotective Agents; Protein Kinase Inhibitors; Rats, Sprague-Dawley; Recovery of Function; Spinal Cord; Spinal Cord Injuries; TOR Serine-Threonine Kinases; Up-Regulation

To evaluate the effects of interleukin-6 (IL-6) and erythropoietin (EPO) in experimental acute spinal cord injury (SCI) in rats.. Using standardized equipment, namely, a New York University (NYU) Impactor, a SCI was produced in 50 Wistar rats using a 10-g weight drop from a 12.5-mm height. The rats were divided into the following 5 groups of 10 animals each: "Group EPO", treated with erythropoietin only; "Group EPO + IL-6", treated with both substances; "Group IL-6", receiving IL-6 administration only; "Group Placebo", receiving a placebo solution; and "Group Sham", submitted to an incomplete procedure (only laminectomy, without SCI). All drugs and the placebo solution were administered intraperitoneally for three weeks. The animals were followed up for 42 days. Functional motor recovery was monitored by the Basso, Beattie, and Bresnahan (BBB) scale on days 2, 7, 14, 21, 28, 35 and 42. Motor-evoked potential tests were performed on the 42nd day. Histological analysis was performed after euthanasia.. The group receiving EPO exhibited superior functional motor results on the BBB scale. IL-6 administration alone was not superior to the placebo treatment, and the IL-6 combination with EPO yielded worse results than did EPO alone.. Using EPO after acute SCI in rats yielded benefits in functional recovery. The combination of EPO and IL-6 showed benefits, but with inferior results compared to those of isolated EPO; moreover, isolated use of IL-6 resulted in no benefit.

Topics: Animals; Disease Models, Animal; Erythropoietin; Evoked Potentials, Motor; Interleukin-6; Male; Neuroprotective Agents; Rats; Rats, Wistar; Recovery of Function; Spinal Cord Injuries

Apoptosis plays an important role in various diseases, including spinal cord injury (SCI). Hyperbaric oxygen (HBO) and erythropoietin (EPO) promote the recovery from SCI, but the relationship between apoptosis and the combination therapeutic effect is not completely clear.. The purpose of this study was to investigate the effects of HBO and EPO on SCI and the mechanisms that underlie their therapeutic benefits.. The study was designed to explore the effects of HBO and EPO on SCI through a randomized controlled trial.. Sixty young developing female Sprague-Dawley rats were randomly divided into groups of 12 rats receiving sham, SCI, HBO, EPO, or HBO plus EPO. The SCI model was modified with the Allen method to better control consistency. HBO was performed for 1 hour per day for a total of 21 days, and EPO was given once per week for a total of 3 weeks. Both methods were performed 2 hours after SCI. Locomotor function was evaluated with the 21-point Basso-Beattie-Bresnahan Locomotor Rating Scale, an inclined-plane test, and a footprint analysis. All genes were detected by Western blotting and immunohistochemistry. The level of cell apoptosis was determined by Hoechst staining.. The results showed that HBO and EPO promoted the recovery of locomotor function in the hind limbs of rats by inhibiting the apoptosis of neurons. During this period, the expression of B-cell lymphoma/leukemia 2 protein (Bcl-2) increased significantly, whereas the expression of Bcl-2-associated X protein (Bax) and cleaved caspase 3 decreased significantly, indicating the inhibition of apoptosis. Meanwhile, the expression of G protein-coupled receptor 17 decreased, and that of myelin basic protein increased, suggesting that there may be a potential connection between demyelination and neuronal apoptosis.. The limitations of the study include deviations in the preparation of SCI models; lack of reverse validation of molecular mechanisms; absence of in vitro cell experiments; and only one time point after SCI was studied.. HBO and EPO treatments are beneficial for SCI, especially when the 2 therapies are combined.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Caspase 3; Combined Modality Therapy; Drug Administration Schedule; Erythropoietin; Female; Hyperbaric Oxygenation; Locomotion; Myelin Basic Protein; Neurons; Proto-Oncogene Proteins c-bcl-2; Random Allocation; Rats; Rats, Sprague-Dawley; Receptors, G-Protein-Coupled; Recovery of Function; Spinal Cord Injuries

There is mounting experimental evidence that therapeutic hypothermia (TH) mitigates secondary mechanisms of spinal cord injury (SCI). There is a potential synergistic neuroprotective effect for SCI through the combination of TH and other promising therapies. The treatment of TH for SCI has promising results in adults, but its use is anecdotal in newborns with SCI. SCI is a rare, serious, and often fatal complication of instrumental delivery. For the first time, we describe the case of a male newborn infant with upper SCI who was born at term age and was offered whole-body cooling and erythropoietin treatment with unsuccessful outcome. There are still many unresolved issues related to TH in the SCI, some of them specific to the neonatal patient. Accurately establishing the diagnosis and its severity is crucial to redirect care for SCI and to indicate potential neuroprotective therapies. Considering the lack of therapeutic options, the extremely poor outcomes associated with acute SCI, and the extensive experience in safe use of whole-body cooling in newborn infants, we feel that moderate whole-body cooling should be offered as soon as possible after birth to the newborn infant with SCI.

Topics: Apgar Score; Cervical Vertebrae; Combined Modality Therapy; Erythropoietin; Fatal Outcome; Humans; Hypothermia, Induced; Hypoxia-Ischemia, Brain; Infant, Newborn; Male; Obstetrical Forceps; Spinal Cord Injuries; Time-to-Treatment; Treatment Outcome

Erythropoietin (Epo) exhibits promising neuroregenerative potential for spinal cord injury (SCI), and might be involved in other long-term sequelae, such as neuropathic pain development. The current studies investigated the time courses and spatial and cellular patterns of Epo and erythropoietin receptor (EpoR) expression along the spinal axis after graded SCI. Male Long Evans rats received 100 kdyn, 150 kdyn, and 200 kdyn thoracic (T9) contusions from an Infinite Horizon impactor. Sham controls received laminectomies. Anatomical and quantitative immunohistochemical analyses of the EpoR/Epo expression along the whole spinal axis were performed 7, 15, and 42 postoperative days (DPO) after the lesioning. Cellular expression was investigated by double- and triple-labeling for EpoR/Epo with cellular markers and proliferating cells in subgroups of 5-bromo-2-deoxyuridine pre-treated animals. Prolonged EpoR/Epo-expression was confirmed by real-time reverse transcriptase polymerase chain reaction (RT-PCR). Quantified EpoR/Epo immunoreactivities in pain-related spinal cord regions and ventrolateral white matter (VLWM) were correlated with the mechanical sensitivity thresholds and locomotor function of the respective animals. EpoR and Epo were constitutively expressed in the ventral horn neurons and vascular and glial cells in the dorsal columns (DC) and the VLWM. After SCI, in addition to expression in the lesion core, EpoR/Epo immunoreactivities exhibited significant time- and lesion grade-dependent induction in the DC and VLWM along the spinal axis. EpoR and Epo immunoreactive cells were co-stained with markers for astroglial, neural precursor cell and vascular markers. In the VLWM, EpoR- and Epo-positive proliferating cells were co-stained with glial fibrillary acidic protein (GFAP) and nestin. The DC EpoR/Epo immunoreactivities exhibited linear relationships with the behavioral correlates of post-lesional chronic pain development at DPO 42. SCI leads to long-lasting multicellular EpoR/Epo induction beyond the lesion core in the spinal cord regions that are involved in central pain development and regenerative processes. Our studies provide a time frame to investigate the effects of Epo application on motor function or pain development, especially in the later time course after lesioning.

Topics: Animals; Erythropoietin; Male; Rats; Rats, Long-Evans; Receptors, Erythropoietin; Spinal Cord; Spinal Cord Injuries

Erythropoietin (Epo) promotes functional recovery following spinal cord injury (SCI); however, the exact underlying mechanisms are yet to be determined. Although endogenous neural stem cells (NSCs) in the adult spinal cord are a therapeutic target in SCI models, the effect of Epo on this NSC population remains unknown. The present study investigated the effects of Epo on endogenous NSCs in the adult spinal cord both in vitro and in vivo. For the in vivo analyses, normal rats (Normal) and SCI contusion model rats (SCI) received either recombinant human Epo or saline treatment for 7 days (5,000 U/kg), and spinal cords were subsequently analyzed at 2, 8, and 14 days. For in vitro analyses, NSCs harvested from adult rat spinal cords were exposed to Epo (10 U/ml). A significant increase in β‑tubulin+ new neurons (P<0.01) was observed at all three time points and O4+ new oligodendrocytes (P<0.05) at days 8 and 14 in the SCI+Epo group compared with the SCI+Saline group. This was concomitant with a prolonged activation of Epo signaling; however, no effect on NSCs proliferation was observed. Similar results were also obtained in vitro. Motor functional recovery was also noted at days 8 and 14 only in the Epo‑treated SCI rats. Although the expression of Epo and EpoR significantly increased in Normal+Epo rats compared with Normal+Saline rats (P<0.05), the cell numbers and phenotype were comparable between the two groups. To the best of the author's knowledge, this is the first study to demonstrate that Epo signaling promotes both neurogenesis and oligodendrogenesis following SCI and that these may represent the underlying mechanisms for the functional recovery and therapeutic effects of Epo following SCI.

Topics: Animals; Cell Differentiation; Disease Models, Animal; Erythropoietin; Female; Humans; Motor Activity; Neural Stem Cells; Neurogenesis; Oligodendroglia; Rats; Receptors, Erythropoietin; Recovery of Function; Regeneration; Spinal Cord Injuries

Spinal cord injury (SCI) is an incurable disease causing an ischemic environment and functional defect, thus a new therapeutic approach is needed for SCI treatment. Vascular endothelial growth factor (VEGF) is a potent therapeutic gene to treat SCI via angiogenesis and neuroprotection, and both tissue-specific gene expression and high gene delivery efficiency are important for successful gene therapy. Here we design the hypoxia/neuron dual-specific gene expression system (pEpo-NSE) and efficient gene delivery platform can be achieved by the combination ex vivo gene therapy with erythropoietin (Epo) enhancer, neuron-specific enolase (NSE) promoter and neural stem cells (NSCs). An in vitro model, NSCs transfected with pEpo-NSE were consistently and selectively overexpressing therapeutic genes in response to neural differentiation and hypoxic conditions. Also, in SCI model, ex vivo gene therapy using pEpo-NSE system with NSCs significantly enhanced gene delivery efficiency compared with pEpo-NSE system gene therapy alone. However, microarray analysis reveals that introducing exogenous pEpo-NSE and VEGF triggers biological pathways in NSCs such as glycolysis and signaling pathways such as Ras and mitogen-activated protein kinase, leading to cell proliferation, differentiation and apoptosis. Collectively, it indicates that the pEpo-NSE gene expression system works stably in NSCs and ex vivo gene therapy using pEpo-NSE system with NSCs improves gene expression efficiency. However, exogenously introduced pEpo-NSE system has an influence on gene expression profiles in NSCs. Therefore, when we consider ex vivo gene therapy for SCI, the effects of changes in gene expression profiles in NSCs on safety should be investigated.

Topics: Animals; Apoptosis; Cell Differentiation; Cell Hypoxia; Cell Proliferation; Enhancer Elements, Genetic; Erythropoietin; Gene Expression Profiling; Genetic Therapy; HEK293 Cells; Humans; Neural Stem Cells; Oligonucleotide Array Sequence Analysis; PC12 Cells; Phosphopyruvate Hydratase; Promoter Regions, Genetic; Rats; Spinal Cord Injuries; Vascular Endothelial Growth Factor A

The objective of this study was to investigate the underlying molecular mechanisms and the therapeutic time window for preventing astrogliosis with erythropoietin (EPO) treatment after in vitro modeled spinal cord injury (SCI).. Cultured rat spinal cord astrocytes were treated with kainate and scratching to generate an in vitro model of SCI. EPO (100U/mL or 300U/mL) was added immediately or 2, 4, or 8 hours after injury. Some cultures were also treated with AG490, an inhibitor of the EPO-EPO receptor (EpoR) pathway mediator Janus kinase 2 (JAK2). To evaluate neurite extension, rat embryonic spinal cord neurons were seeded onto astrocyte cultures and treated with EPO immediately after injury in the presence or absence of anti-EpoR antibody.. EPO treatment at up to 8 hours after injury reduced the expression of axonal growth inhibiting molecules (glial fibrillary acidic protein, vimentin, and chondroitin sulfate proteoglycan), cytoskeletal regulatory proteins (Rho-associated protein kinase and ephephrin A4), and proinflammatory cytokines (tumor necrosis factor-alpha, transforming growth factor-beta, and phosphorylated-Smad3) in a dosedependent manner (P < .001). Most effects peaked with EPO treatment 2-4hours after injury. Additionally, EPO treatment up to 4 hours after injury promoted expression of the EpoR (>2-fold) and JAK2 (>3-fold) in a dose-dependent manner (P < .001), whereas co-treatment with AG490 precluded these effects (P < .001). EPO treatment up to 4hours after injury also enhanced axonal b-III tubulin-immunoreactivity (>12-fold), and this effect was precluded by co-treatment with an anti-EpoR antibody (P < .001).. EPO treatment within 8 hours after injury reduced astrogliosis, and EPO treatment within 4 hours promoted neurite outgrowth. EPO therapy immediately after spinal cord injury may regulate glia to generate an environment permissive of axonal regeneration.

Topics: Animals; Astrocytes; Axons; Cells, Cultured; Drug Administration Schedule; Erythropoietin; Gliosis; Neuronal Outgrowth; Rats; Rats, Sprague-Dawley; Spinal Cord Injuries; Time-to-Treatment

Topics: Erythropoietin; Humans; Spinal Cord Injuries

Paraplegia remains the most feared complication of complex thoracoabdominal aortic intervention. Although erythropoietin (EPO) has demonstrated neuroprotective effects in spinal cord ischemia, it does not work until expression of the beta common receptor subunit of the EPO receptor (βcR) is induced by ischemia. We hypothesized that the βcR can be induced by diazoxide (DZ), amplifying the neuroprotective effects of EPO in spinal cord ischemia-reperfusion injury.. For the DZ time trial, adult male C57/BL6 mice received DZ (20 mg/kg) by oral gavage. Spinal cords were harvested after 0, 12, 24, 36, and 48 hours of administration. To evaluate optimal dosing, DZ was administered at 0, 5, 10, 20, and 40 mg/kg. The expression of βcR was assessed by Western blot analysis. Five groups were studied: PBS (pretreatment)+PBS (immediately before), PBS+EPO, DZ+PBS, DZ+EPO, and sham (without cross-clamping). Spinal cord ischemia was induced by 4 minutes of thoracic aortic cross-clamping. Functional scoring (Basso Mouse Score) was done at 12-hour intervals for 48 hours, and spinal cords were harvested for histological analysis.. Western blot analysis demonstrated that optimal βcR up-regulation occurred at 36 hours after DZ administration, and the optimal DZ dosage for βcR induction was 20 mg/kg. Motor function at 48 hours after treatment was significantly better preserved in the DZ+EPO group compared with all other groups, and was significantly better preserved in the DZ only and EPO only groups compared with control (PBS+PBS).. Pharmacologic up-regulation of βcR with DZ can increase the efficacy of EPO in preventing spinal cord ischemia and reperfusion injury. Improved understanding of this synergetic mechanism may serve to further prevent ischemic complications for high-risk aortic intervention.

Topics: Animals; Diazoxide; Erythropoietin; Male; Mice; Mice, Inbred C57BL; Neuroprotective Agents; Receptors, Erythropoietin; Signal Transduction; Spinal Cord; Spinal Cord Injuries; Spinal Cord Ischemia

Autophagy has been regarded as a promising therapeutic target for spinal cord injury (SCI). Erythropoietin (EPO) has been demonstrated to exhibit neuroprotective effects in the central nervous system (CNS); however, the molecular mechanisms of its protection against SCI remain unknown. This study aims to investigate whether the neuroprotective effects of EPO on SCI are mediated by autophagy via AMP-activated protein kinase (AMPK) signaling pathways.. Functional assessment and Nissl staining were used to investigate the effects of EPO on SCI. Expressions of proteins were detected by Western blot and immunohistochemistry.. Treatment with EPO significantly reduced the loss of motor neurons and improved the functional recovery following SCI. Erythropoietin significantly enhanced the SCI-induced autophagy through activating AMPK and inactivating mTOR signaling. The inhibitor of AMPK, compound C, could block the EPO-induced autophagy and beneficial action on SCI, whereas the activator of AMPK, metformin, could mimic the effects of EPO. In the in vitro studies, EPO enhanced the hypoxia-induced autophagy in an AMPK-dependent manner.. The AMPK-dependent induction of autophagy contributes to the neuroprotection of EPO on SCI.

Topics: AMP-Activated Protein Kinases; Animals; Autophagy; Cell Hypoxia; Disease Models, Animal; Dose-Response Relationship, Drug; Enzyme Inhibitors; Erythropoietin; Glucose; Locomotion; Male; Microtubule-Associated Proteins; Neuroprostanes; PC12 Cells; Rats; Rats, Sprague-Dawley; Recovery of Function; Signal Transduction; Spinal Cord Injuries

Topics: Erythropoietin; Humans; Spinal Cord; Spinal Cord Injuries

Spinal cord injury (SCI) is a debilitating condition characterized by a complex of neurological dysfunctions ranging from loss of sensation to partial or complete limb paralysis. Recently, we reported that intravenous administration of neural precursors physiologically releasing erythropoietin (namely Er-NPCs) enhances functional recovery in animals following contusive spinal cord injury through the counteraction of secondary degeneration. Er-NPCs reached and accumulated at the lesion edges, where they survived throughout the prolonged period of observation and differentiated mostly into cholinergic neuron-like cells.. The aim of this study was to investigate the potential reparative and regenerative properties of Er-NPCs in a mouse experimental model of traumatic spinal cord injury.. We report that Er-NPCs favoured the preservation of axonal myelin and strongly promoted the regrowth across the lesion site of monoaminergic and chatecolaminergic fibers that reached the distal portions of the injured cord. The use of an anterograde tracer transported by the regenerating axons allowed us to assess the extent of such a process. We show that axonal fluoro-ruby labelling was practically absent in saline-treated mice, while it resulted very significant in Er-NPCs transplanted animals.. Our study shows that Er-NPCs promoted recovery of function after spinal cord injury, and that this is accompanied by preservation of myelination and strong re-innervation of the distal cord. Thus, regenerated axons may have contributed to the enhanced recovery of function after SCI.

Topics: Animals; Choline O-Acetyltransferase; Dextrans; Disease Models, Animal; Erythropoietin; Fluorescent Dyes; GAP-43 Protein; Locomotion; Male; Mice; Microtubule-Associated Proteins; Myelin Sheath; Nerve Regeneration; Organic Chemicals; Recovery of Function; Rhodamines; Serotonin; Spinal Cord Injuries; Stem Cell Transplantation; Tubulin; Tyrosine 3-Monooxygenase

Experimental study with rats.. To evaluate functional and histological effects of tacrolimus (FK 506) and erythropoietin (EPO) after experimental spinal cord contusion injury (SCI).. Brazil.. Wistar rats (n=60) were submitted to SCI with the NYU Impactor system. The control group received saline; the EPO group received EPO; the group EPO+FK 506 received EPO associated with tacrolimus and the group FK 506 received tacrolimus only. The Sham group underwent SCI, but did not receive any drug. Locomotor function was evaluated after SCI by BBB (Basso, Beattie and Bresnahan) weekly and by the motor-evoked potential test in 42 days. The spinal cord was histologically evaluated.. There was a significant difference between treated and the control groups from the seventh day on for BBB scores, with no difference between the groups EPO and EPO+FK 506 by the end of the study. There were significant differences between groups for necrosis and bleeding, but not for hiperemia, degeneration and cellular infiltrate. Axon neuron count was different between all groups (P=0.001), between EPO+FK 506 and FK 506 (P=0.011) and between EPO+FK 506 and Sham (P=0.002). Amplitude was significantly different between all groups except between control and sham. For latency, there was no difference.. This study did not reveal significant differences in the recovery of locomotor function, or in the histological and electrophysiological analysis in animals treated with EPO and tacrolimus after thoracic SCI.

Topics: Animals; Disease Models, Animal; Erythropoietin; Evoked Potentials, Motor; Follow-Up Studies; Immunosuppressive Agents; Locomotion; Nervous System Diseases; Rats; Rats, Wistar; Recovery of Function; Spinal Cord Injuries; Statistics, Nonparametric; Tacrolimus; Time Factors

To evaluate the functional and histological effects of ganglioside G(M1) and erythropoietin after experimental spinal cord contusion injury.. Fifty male Wistar rats underwent experimental spinal cord lesioning using an NYU-Impactor device and were randomly divided into the following groups, which received treatment intraperitoneally. The G(M1) group received ganglioside G(M1) (30 mg/kg); the erythropoietin group received erythropoietin (1000 IU/kg); the combined group received both drugs; and the saline group received saline (0.9%) as a control. A fifth group was the laminectomy group, in which the animals were subjected to laminectomy alone, without spinal lesioning or treatment. The animals were evaluated according to the Basso, Beattie and Bresnahan (BBB) scale, motor evoked potential recordings and, after euthanasia, histological analysis of spinal cord tissue.. The erythropoietin group had higher BBB scores than the G(M1) group. The combined group had the highest BBB scores, and the saline group had the lowest BBB scores. No significant difference in latency was observed between the three groups that underwent spinal cord lesioning and intervention. However, the combined group showed a significantly higher signal amplitude than the other treatment groups or the saline group (p<0.01). Histological tissue analysis showed no significant difference between the groups. Axonal index was significantly enhanced in the combined group than any other intervention (p<0.01).. G(M1) and erythropoietin exert therapeutic effects on axonal regeneration and electrophysiological and motor functions in rats subjected to experimental spinal cord lesioning and administering these two substances in combination potentiates their effects.

Topics: Animals; Drug Therapy, Combination; Erythropoietin; G(M1) Ganglioside; Injections, Intraperitoneal; Locomotion; Male; Models, Animal; Necrosis; Neuroprotective Agents; Random Allocation; Rats, Wistar; Reaction Time; Recovery of Function; Spinal Cord Injuries

The aim of this study was to compare the preventive effects of Etanercept, Etomidate, Erythropoietin and their combination in experimentally induced spinal cord trauma by clinical, histopathological, electrophysiological parameters and biochemical examination.. 85 healthy female Wistar-Albino rats were used in this study. Rats were divided 8 trauma groups that consisted of 10 rats for each, and 5 rats for the sham group. Laminectomy was performed under general anesthesia and the spinal cord was exposed with intact dura mater, and injury was created by the clip compression model. After the spinal cord injury, drugs were administered immediately intraperitoneally or subcutaneously. Except the sham group, all groups received drugs and were observed 24 or 72 hours. At the 72nd hour each group was anesthesized and somatosensorial evoked potentials (SEP) were recorded from the interarcuate ligament from the 2 vertebra proximal to the injured spinal cord and spinal cord tissue samples were taken for histopathological and biochemical evaluation.. Etomidate groups showed a lower effect on spinal cord injury than etanercept and erythropoietin in terms of clinical, SEP and TNF-α. Etanercept and erythropoietin's neuroprotective effectiveness was shown alone or in combination treatments. More meaningful results were achieved with the use of erythropoietin and etanercept combination after spinal cord injury (SCI) than using erythropoietin alone. After SCI, highest Basso, Beattie, and Bresnahan (BBB) scores were achieved in the group which Etanercept and Erythropoietin applied together.. The neuroprotective activity of etomidate was suspect. The neuroprotective effect of etanercept and erythropoietin after SCI was shown in individual and combined applications in this study. However, more experimental studies are needed for clinical use.

Topics: Animals; Disease Models, Animal; Drug Synergism; Drug Therapy, Combination; Erythropoietin; Etanercept; Etomidate; Evoked Potentials, Somatosensory; Female; Neuroprotective Agents; Rats; Spinal Cord Injuries; Tumor Necrosis Factor-alpha

This experimental study was an investigation of the efficacy of erythropoietin and tadalafil in rats with induced spinal cord injury (SCI).. Thirty-five Sprague Dawley rats were distributed into 5 groups. First group was used for normal biochemical values. Spinal cord injury was induced in 4 remaining groups with clip compression technique after laminectomy process to T10 vertebra. Second group was designated solvent group and received 1 cc physiological serum after injury. Third group was medicated with intraperitoneal 2000 u/kg single dose erythropoietin after injury. Orogastric 2 mg/kg single dose tadalafil was administered to fourth group after injury. Fifth group did not receive any treatment and was used for biochemical values with injury. All subjects were sacrificed 48 hours after application. Malondialdehyde (MDA) and total antioxidant capacity (TAOC) values were evaluated using blood and tissue samples.. Lowest serum and tissue MDA values were found in group with erythropoietin intake. While highest serum TAOC values of all groups were seen in tadalafil group, highest tissue TAOC values were observed in group given erythropoietin.. It was concluded that by decreasing oxidative stress, tadalafil and erythropoietin can inhibit secondary damage in SCI.

Topics: Administration, Oral; Animals; Disease Models, Animal; Drug Therapy, Combination; Erythropoietin; Infusions, Parenteral; Male; Neuroprotective Agents; Random Allocation; Rats; Rats, Sprague-Dawley; Spinal Cord Injuries; Tadalafil; Thoracic Vertebrae

Spinal cord injury (SCI) is a debilitating clinical condition, characterized by a complex of neurological dysfunctions. Neural stem cells from the subventricular zone of the forebrain have been considered a potential tool for cell replacement therapies. We recently isolated a subclass of neural progenitors from the cadaver of mouse donors. These cells, named postmortem neural precursor cells (PM-NPCs), express both erythropoietin (EPO) and its receptor. Their EPO-dependent differentiation abilities produce a significantly higher percentage of neurons than regular NSCs. The cholinergic yield is also higher. The aim of the present study was to evaluate the potential repair properties of PM-NPCs in a mouse model of traumatic SCI. Labeled PM-NPCs were administered intravenously; then the functional recovery and the fate of transplanted cells were studied. Animals transplanted with PM-NPCs showed a remarkable improved recovery of hindlimb function that was evaluated up to 90 days after lesion. This was accompanied by reduced myelin loss, counteraction of the invasion of the lesion site by the inflammatory cells, and an attenuation of secondary degeneration. PM-NPCs migrate mostly at the injury site, where they survive at a significantly higher extent than classical NSCs. These cells accumulate at the edges of the lesion, where a reach neuropile is formed by MAP2- and β-tubulin III-positive transplanted cells that are also mostly labeled by anti-ChAT antibodies.

Topics: Animals; Behavior, Animal; Cell Movement; Cells, Cultured; Erythropoietin; Hindlimb; Magnetic Resonance Imaging; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Myelin Sheath; Neural Stem Cells; Optical Imaging; Radiography; Receptors, Erythropoietin; Recovery of Function; Spinal Cord Injuries; Transplantation, Homologous

Insulin-like growth factor 1 (IGF-1) and erythropoietin (EPO) have been reported to independently protect against ischemic spinal cord injury in rabbits. In the present study, we investigated whether the combination of IGF-1 and EPO protects against ischemic spinal cord injury in rabbits.. Animals were assigned to 1 of 4 groups (n = 6 in each): a control group (saline), an IGF-1 group (IGF-1 0.3 mg/kg), an EPO group (EPO 800 U/kg), or an IGF-1 + EPO group (IGF-1 0.3 mg/kg + EPO 800 U/kg). Spinal cord ischemia was produced by occluding the abdominal aorta for 15 min. Saline, IGF-1, and EPO were administered intravenously just after the start of reperfusion. Hindlimb motor function was assessed daily for 7 days, after which histopathological evaluation was performed. To analyze phosphorylation of signal transduction molecules, animals were assigned to 1 of the 4 groups (n = 8 in each). Spinal cord ischemia and the treatment were the same as those described above. The spinal cords were removed at 15 or 30 min after reperfusion and used to analyze phosphorylation of signal transduction molecules. Four animals served as the preischemic control, and the spinal cord was removed just before the start of ischemia.. In the IGF-1 + EPO group, both neurological and histopathological outcomes were significantly improved as compared to the control group, which was consistent with the increase of Janus kinase-2 (JAK2) phosphorylation.. The combination of IGF-1 and EPO protects against ischemic spinal cord injury in rabbits. JAK2 might contribute to the protective effect.

Topics: Animals; Erythropoietin; Insulin-Like Growth Factor I; Male; Neuroprotective Agents; Phosphorylation; Rabbits; Spinal Cord Injuries; Spinal Cord Ischemia

Accumulating evidence has indicated that the stromal cell-derived factor-1 (SDF-1)/CXC chemokine receptor 4 (CXCR4) axis plays a crucial role in the recruitment of bone marrow-derived mesenchymal stem cells (BMSCs) into lesion sites in animal models. The aim of this study was to investigate the effects of the SDF-1/CXCR4 axis on the migration of transplanted BMSCs mobilized by erythropoietin (EPO) toward the lesion site following spinal cord injury (SCI). A model of SCI was established in rats using the modified Allen's test. In the EPO group, EPO was administered at a distance of 2 mm cranially and then 2 mm caudally from the site of injury. In the BMSC group, 10 µl of BMSC suspension was administered in the same manner. In the BMSC + EPO group, both BMSCs and EPO were administered as described above. In the BMSC + EPO + AMD3100 group, in addition to the injection of BMSCs and EPO, AMD3100 (a chemokine receptor antagonist) was administered. The Basso-Beattie-Bresnahan (BBB) Locomotor Rating Scale and a grid walk test were used to estimate the neurological recovery following SCI. Enzyme-linked immunosorbent assay (ELISA) was performed to assess the tumor necrosis factor-α (TNF-α) and SDF-1 expression levels. An immunofluorescence assay was performed to identify the distribution of the BMSCs in the injured spinal cord. A Transwell migration assay was performed to examine BMSC migration. A terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay was performed to detect the apoptotic index (AI). Western blot analysis was performed to measure the expression levels of erythropoietin receptor (EPOR) and CXCR4. Significant improvements in locomotor function were detected in the BMSC + EPO group compared with the BMSC group (P<0.05). GFP-labeled BMSCs were observed and were located at the lesion sites. Additionally, EPO significantly decreased the TNF-α levels and increased the SDF-1 levels in the injured spinal cord (P<0.05).The AI in the BMSC + EPO group was significantly lower compared with that in the other groups (P<0.05). Furthermore, EPO significantly upregulated the protein expression of CXCR4 in the BMSCs and promoted the migration of the BMSCs, whereas these effects were markedly inhibited when the BMSCs were co-transplanted with AMD3100. The findings of the present study confirm that EPO mobilizes BMSCs to the lesion site following SCI and enhances the anti-apoptotic effects of the BMSCs by upregulating the expression of SDF-

Topics: Animals; Benzylamines; Cell Movement; Chemokine CXCL12; Cyclams; Erythropoietin; Female; Heterocyclic Compounds; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Rats; Rats, Sprague-Dawley; Receptors, CXCR4; Spinal Cord; Spinal Cord Injuries; Tumor Necrosis Factor-alpha

A previous study showed that a 1-h delay in treatment of thoracic spinal cord injury (SCI) with recombinant human erythropoietin (rhEPO) lacked neuroprotective efficacy. The aim of the present study was to reassess delayed administration of different doses of rhEPO on acute spinal cord compressive injury in rats.. The experiment was divided into first and second stages, which SCI rats were observed for 4 and 28 days, respectively. All rats were randomly divided into four groups at both stages: control group, and rhEPO-3,000U (Unit), rhEPO-4,000U and rhEPO-5,000U groups. SCI rats received rhEPO treatment at different time points. The primary indicators were locomotor recovery, histopathology, apoptotic index, inflammatory index, ultrastructural scoring system and volume of areas of demyelination.. The most significant locomotor functional and histopathological improvements and the best myelin protection were observed after administration of 5,000 U/kg rhEPO. rhEPO at 3,000, 4,000 and 5,000 U/kg showed similar ultrastructural neuroprotection, as well as similar inhibition of apoptosis and regulation of inflammation.. Delayed administration of rhEPO can reduce apoptosis and inflammation, and promote myelin repair and functional recovery following spinal cord compressive injury in rats.

Topics: Animals; Apoptosis; Behavior, Animal; Disease Models, Animal; Erythropoietin; Humans; Inflammation; Male; Motor Activity; Myelin Sheath; Random Allocation; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Recovery of Function; Spinal Cord Compression; Spinal Cord Injuries; Time Factors

We investigated the effect of neural stem cells (NSC) and erythropoietin (EPO) on axon regeneration in adult rats with transected spinal cord injury, and provided an experimental basis for clinical treatment. Forty Wistar rats with T10-transected spinal cord injury were randomly divided into four groups of ten rats: a control group (group A), an NSC-transplant group (group B), an NSC-transplant and EPO group (group C), and an EPO group (group D). Biotinylated dextran amines (BDA) anterograde corticospinal cord neuronal tracing and Fluoro-Gold (FG) retrograde tracing were carried out at the 8th week after operation to observe the regeneration of nerve fibers. The Basso, Beattie, and Bresnahan (BBB) locomotor score was used to evaluate restoration. 1) BDA and FG immunofluorescence staining: in group C, a large number of regenerated axons were observed and some penetrated the injured area. In group B, only a small number of regenerated axons were observed and none penetrated the injured area. In group D, only sporadic regenerated nerve fibers were observed occasionally, while in group A, no axonal regeneration was observed. In group C, a small number of cones and axons emitted yellow fluorescence, and no FG-labeled cells were observed in the other groups. 2) The BBB scores for group C were higher than those for the other groups, and the differences were statistically significance (P < 0.05). NSC transplantation combined with EPO intraperitoneal injection may benefit axon regeneration in rats with transected spinal cord injury, and accelerate the functional recovery of the hindlimb locomotor.

Topics: Animals; Axons; Erythropoietin; Humans; Nerve Regeneration; Neural Stem Cells; Rats; Recovery of Function; Spinal Cord Injuries

Erythropoietin has demonstrated neuroprotective effects against traumatic spinal cord injury (SCI), but the underlying mechanisms remain unclear. The signaling pathway of an antioxidant transcription factor, nuclear factor erythroid 2-related factor 2 (Nrf2), has been shown to play an important role in protecting SCI-induced secondary spinal cord damage. This study was undertaken to explore the effect of recombinant human erythropoietin (rhEPO) on the activation of Nrf2 signaling pathway and secondary spinal cord damage in rats after SCI.. Adult male Sprague-Dawley rats were subjected to laminectomy at T8-T9 and compression with a vascular clip. Three groups were analyzed: (1) sham group, (2) SCI group, and (3) SCI + rhEPO group (n = 16 per group). In the SCI + rhEPO group, rhEPO was administered at a dose of 5,000 IU/kg at 30 minutes after SCI. Spinal cord samples were extracted at 72 hours after the trauma.. As a result, we found that the treatment with rhEPO markedly up-regulated the messenger RNA expressions and activities of Nrf2 signaling pathway-related agents, including Nrf2, NAD(P)H:quinone oxidoreductase 1(NQO1), and glutathione S-transferase. The administration of rhEPO also significantly ameliorated the secondary spinal cord damage, as shown by a decreased severity of locomotion deficit, spinal cord edema, and apoptosis.. Post-SCI rhEPO administration induces Nrf2-mediated cytoprotective response in the injured spinal cord, and this may be a mechanism whereby rhEPO improves the outcome following SCI.

Topics: Animals; Apoptosis; Biomarkers; Disease Models, Animal; Erythropoietin; Glutathione Transferase; In Situ Nick-End Labeling; Locomotion; Male; Neuroprotective Agents; NF-E2-Related Factor 2; Random Allocation; Rats; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction; RNA, Messenger; Sensitivity and Specificity; Signal Transduction; Spinal Cord Injuries

Topics: Adrenal Cortex Hormones; Anticholesteremic Agents; Authorship; Bias; Conflict of Interest; Controlled Clinical Trials as Topic; Drug Administration Schedule; Drug Industry; Early Termination of Clinical Trials; Erythropoietin; Evidence-Based Medicine; Fear; Fibrinolytic Agents; Guideline Adherence; Humans; Malpractice; National Institutes of Health (U.S.); Periodicals as Topic; Practice Guidelines as Topic; Societies, Medical; Spinal Cord Injuries; Standard of Care; Stroke; Tissue Plasminogen Activator; Trust; United States

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a hematopoietic cytokine that stimulates the differentiation and function of hematopoietic cells. GM-CSF has been implicated in nervous system function. The goal of the present study was to understand the effects of hypoxia-induced GM-CSF on neural stem cells (NSCs) in a model of spinal cord injury (SCI). GM-CSF-overexpressing NSCs were engineered utilizing a hypoxia-inducible gene expression plasmid, including an Epo enhancer ahead of an SV promoter (EpoSV-GM-CSF). Cells were then subjected to hypoxia (pO(2), 1%) or a hypoxia-mimicking reagent (CoCl(2)) in vitro. The progression of time of GM-CSF expression was tracked in EpoSV-GM-CSF-transfected NSCs. Overexpression of GM-CSF in undifferentiated and differentiated NSCs created resistance to H(2)O(2)-induced apoptosis in hypoxia. NSCs transfected with EpoSV-GM-CSF or SV-GM-CSF were transplanted into rats after SCI to assess the effect of GM-CSF on NSC survival and restoration of function. Moreover, a significantly higher amount of surviving NSCs and neuronal differentiation was observed in the EpoSV-GM-CSF-treated group. Significant improvement in locomotor function was also found in this group. Thus, GM-CSF overexpression by the Epo enhancer in hypoxia was beneficial to transplanted NSC survival and to behavioral improvement, pointing toward a possible role for GM-CSF in the treatment of SCI.

Topics: Animals; Cell Hypoxia; Enhancer Elements, Genetic; Erythropoietin; Gene Transfer Techniques; Graft Survival; Granulocyte-Macrophage Colony-Stimulating Factor; Male; Neural Stem Cells; Plasmids; Promoter Regions, Genetic; Rats; Rats, Sprague-Dawley; Recovery of Function; Simian virus 40; Spinal Cord Injuries

We evaluated the therapeutic effect of erythropoietin (EPO) delivered by direct injection of a nonreplicating herpes simplex virus (HSV)-based vector coding for EPO (vEPO) in a model of cervical hemicord contusion at C7. At 1 h after spinal cord injury (SCI), either vEPO or control vector carrying a reporter gene (vC) was injected into the cord above and below the lesion. Animals injected with vEPO showed a statistically significant improvement in the ipsilateral forelimb function, as measured by open-field evaluation of motor performance, forelimb reaching in the cylinder test and misplacement in grid walk. This correlated with preservation of gray matter in the area of the lesion. There was also mild but significant improvement of hindlimb motor function measured by Basso-Beattie-Bresnahan score and computerized gait analysis in vEPO compared with control vector-injected animals. Microtubule-associated protein tau, phosphorylated and nonphosphorylated neurofilament protein and the synaptic proteins synaptophysin and PSD-95 were all significantly increased in the spinal cord of vEPO-treated animals compared with control vector-injected animals. These data suggest that gene transfer of EPO after cervical SCI by minimizing the injury size and enhancing tissue sparing preserves large-caliber axons and promotes synaptogenesis.

Topics: Animals; Contusions; Erythropoietin; Female; Forelimb; Genetic Vectors; Hindlimb; Microtubule-Associated Proteins; Neurofilament Proteins; Rats; Rats, Sprague-Dawley; Recovery of Function; Simplexvirus; Spinal Cord; Spinal Cord Injuries; Transfection

Erythropoietin has been shown to promote tissue regeneration after ischaemic injury in various organs. Here, we investigated whether Erythropoietin could ameliorate ischaemic spinal cord injury in the mouse and sought an underlying mechanism. Spinal cord ischaemia was developed by cross-clamping the descending thoracic aorta for 7 or 9 min. in mice. Erythropoietin (5000 IU/kg) or saline was administrated 30 min. before aortic cross-clamping. Neurological function was assessed using the paralysis score for 7 days after the operation. Spinal cords were histologically evaluated 2 and 7 days after the operation. Immunohistochemistry was used to detect CD34(+) cells and the expression of brain-derived neurotrophic factor and vascular endothelial growth factor. Each mouse exhibited either mildly impaired function or complete paralysis at day 2. Erythropoietin-treated mice with complete paralysis demonstrated significant improvement of neurological function between day 2 and 7, compared to saline-treated mice with complete paralysis. Motor neurons in erythropoietin-treated mice were more preserved at day 7 than those in saline-treated mice with complete paralysis. CD34(+) cells in the lumbar spinal cord of erythropoietin-treated mice were more abundant at day 2 than those of saline-treated mice. Brain-derived neurotrophic factor and vascular endothelial growth factor were markedly expressed in lumbar spinal cords in erythropoietin-treated mice at day 7. Erythropoietin demonstrated neuroprotective effects in the ischaemic spinal cord, improving neurological function and attenuating motor neuron loss. These effects may have been mediated by recruited CD34(+) cells, and enhanced expression of brain-derived neurotrophic factor and vascular endothelial growth factor.

Topics: Animals; Antigens, CD34; Disease Models, Animal; Erythropoietin; Immunohistochemistry; Male; Mice; Mice, Inbred C57BL; Recovery of Function; Spinal Cord; Spinal Cord Injuries; Spinal Cord Ischemia; Survival Analysis; Treatment Outcome

Erythropoietin (EPO) is a variety of tissue-protective functions, including spinal cord. This study aimed to determine the neuron protective effect of erythropoietin on spinal cord injury (SCI) by assessing C/EBP-homologous protein (CHOP) in the development of a rat model of SCI.. Sixty Sprague-Dawley rats were randomly assigned to three groups: sham-operation control group, SCI group, and EPO treatment group. By using a weight-drop contusion SCI model, the rats in the SCI group and EPO treatment group were killed at 1 and 7 days subsequently. The Basso, Beattie, and Bresnahan (BBB) scores were examined for locomotor function. Pathological changes were observed after hematoxylin-eosin (H&E) staining. The expression of CHOP was determined by immunohistochemical staining and RT-PCR analysis.. BBB scores showed more quick recovery in the erythropoietin treatment group than that in the SCI group (P < 0.01). Pathological changes also revealed a reduction in the volume of cavitations and more neurons regeneration in the EPO treatment rats than that of the SCI rats. The number of CHOP positive cells in the SCI group on day 1 and 7 days after SCI increased compared with the erythropoietin treatment group and sham-operation control group (P < 0.01). CHOP mRNA folds in sham-operation control rat from 1 to 7 days showed the same trend.. Endoplasmic reticulum (ER) stress was triggered at the early stage of SCI. Increased expression of CHOP can be found in the injured segment of the spinal cord after injury. EPO treatment could prevent pathological alterations from severe spinal cord injury by reducing expression of CHOP.

Topics: Animals; Disease Models, Animal; Endoplasmic Reticulum Stress; Erythropoietin; Male; Neurons; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Spinal Cord Injuries; Transcription Factor CHOP

Spinal cord injury (SCI) is a debilitating clinical condition, characterized by a complex of neurological dysfunctions. It has been shown in rats that the acute administration of recombinant human erythropoietin (rhEPO) following a contusive SCI improves the recovery of hindlimb motor function, as measured with the locomotor BBB (Basso, Beattie, Bresnahan) scale. This scale evaluates overall locomotor activity, without testing whether the rhEPO-induced motor recovery is due to a parallel recovery of sensory and/or motor pathways. Aim of the present study was to utilize an electrophysiological test to evaluate, in a rat model of contusive SCI, the transmission of both ascending and descending pathways across the damaged cord at 2, 5, 7, 11, and 30 days after lesion, in animals treated with rhEPO (n=25) vs saline solution (n=25). Motor potentials evoked by epicortical stimulation were recorded in the spinal cord, and sensory-evoked potentials evoked by spinal stimulation were recorded at the cortical level. In the same animals BBB score and immunocytochemical evaluation of the spinal segments caudal to the lesion were performed. In rhEPO-treated animals results show a better general improvement both in sensory and motor transmission through spared spinal pathways, supposedly via the reticulo-spinal system, with respect to saline controls. This improvement is most prominent at relatively early times. Overall these features show a parallel time course to the changes observed in BBB score, suggesting that EPO-mediated spared spinal cord pathways might contribute to the improvement in transmission which, in turn, might be responsible for the recovery of locomotor function.

Topics: Animals; Contusions; Disease Models, Animal; Electrophysiology; Erythropoietin; Evoked Potentials, Motor; Evoked Potentials, Somatosensory; Female; Humans; Motor Activity; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Recovery of Function; Spinal Cord Injuries

Recent observations have demonstrated neuroprotective role of erythropoietin (Epo) and Epo receptor in the central nervous system. Here we examined Epo function in the murine spinal cord after transplantation of pluripotent mouse embryonic stem (ES) cells pre-differentiated towards neuronal type following spinal cord injury. Expression of Epo was measured at both mRNA and protein levels in the ES cells as well as in the spinal cords after 1 and 7 days. Our data demonstrated that expression of Epo mRNA, as well as its protein content, in ES cells was significantly decreased after differentiation procedure. In the spinal cords, analysis showed that Epo mRNA level was significantly decreased after 1 day of ES cell injections in comparison to media-injected control. Epo protein level detected by Western blot was diminished as well. Examination of Epo production in the injured spinal cords after media or ES cells injections by indirect immunofluorescence showed increased Epo-immunopositive staining after media injections 1 day after injection. In contrast, ES cell transplantation did not induce Epo expression. Seven days after ES cell injections, Epo-immunopositive cells' distribution in the ipsilateral side was not changed, while the intensity of immunostaining on the contralateral side was increased, approaching levels in control media-injected tissues. Our data let us to presume that previously described immediate positive effects of ES cells injected into the injured zone of spinal cord are not based on Epo, but on other factors or hormones, which should be elucidated further.

Topics: Animals; Cell Differentiation; Cells, Cultured; Disease Models, Animal; Embryonic Stem Cells; Erythropoietin; Flow Cytometry; Gene Expression Regulation; Green Fluorescent Proteins; Mice; Nuclear Receptor Subfamily 4, Group A, Member 2; RNA, Messenger; Spinal Cord Injuries; Time Factors; Transfection

In humans elective spine surgery can cause iatrogenic spinal cord injury (SCI). Efforts for neuroprotection have been directed to avoid mechanical injury by using intraoperative monitoring and improving surgical techniques. There is, however, uncertainty regarding the efficacy of neuroprotective drugs.. Experimental study on the effectiveness of pharmacological neuroprotection in an animal model of spine surgery simulating anticipated mechanically induced neurological damage.. To compare the efficacy of four drugs to protect against the neurological effects of iatrogenic SCI.. Research Unit for Neurological Diseases, IMSS-Proyecto Camina, Mexico City, Mexico.. Erythropoietin, melatonin, cyclosporine-A and methylprednisolone were administered to rats before, during and after controlled spinal cord contusion of mild intensity. Dosage was in accordance with their pharmacokinetic properties and experience gained with experimental SCI. Drug efficacy was assessed by motor function recovery over a period of 6 weeks and by spinal cord morphometry.. Compared with animals treated with saline, the drug-treated groups showed no differences in their locomotor performance, nor in the amount of spared cord tissue. Notably, spontaneous activity was significantly reduced in rats treated with cyclosporine-A.. The neuroprotectant drugs used here perioperatively did not reduce the extent of neurological damage in a model simulating iatrogenic SCI. Therefore, for now, the only protection in elective spine surgery is avoidance of primary injury altogether.

Topics: Analysis of Variance; Animals; Cyclosporine; Disease Models, Animal; Erythropoietin; Female; Locomotion; Melatonin; Methylprednisolone; Neuroprotective Agents; Postoperative Complications; Rats; Rats, Long-Evans; Recombinant Proteins; Recovery of Function; Spinal Cord; Spinal Cord Injuries; Time Factors

After spinal cord injury (SCI), a complex cascade of events leads to tissue degeneration and a penumbra of cell death. Neuroprotective molecules to limit tissue loss are promising; however, intravenous delivery is limited by the blood-spinal cord barrier and short systemic half-life. Current local delivery strategies are flawed: bolus injection results in drug dispersion throughout the intrathecal (IT) space, and catheters/pumps are invasive and open to infection. Our laboratory previously developed a hydrogel of hyaluronan (HA) and methylcellulose (MC) (HAMC) that, when injected into the IT space, was safe and, remarkably, had some therapeutic benefit on its own. In order to test this new paradigm of local and sustained delivery, relative to conventional delivery strategies, we tested, for the first time, the in vivo efficacy of HAMC as an IT drug delivery system by delivering a known neuroprotective molecule, erythropoietin (EPO). In vitro studies showed that EPO was released from HAMC within 16 h, with 80% bioactivity maintained. When the material alone was injected in vivo, individual fluorescent labels on HA and MC showed that HA dissolved from the gel within 24 h, whereas the hydrophobically associated MC persisted in the IT space for 4-7 days. Using a clip compression injury model of moderate severity, HAMC with EPO was injected in the IT space and, in order to better understand the potential of this delivery system, compared to the therapeutic effect of both common delivery strategies-IT EPO and intraperitoneal EPO-and a control of IT HAMC alone. IT HAMC delivery of EPO resulted in both reduced cavitation after SCI and a greater number of neurons relative to the other delivery strategies. These data suggest that the localized and sustained release of EPO at the tissue site by HAMC delivery enhances neuroprotection. This new system of IT delivery holds great promise for the safe, efficacious, and local delivery of therapeutic molecules directly to the spinal cord.

Topics: Animals; Cell Count; Delayed-Action Preparations; Drug Delivery Systems; Erythropoietin; Hyaluronic Acid; Methylcellulose; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Spinal Cord Injuries; Wound Healing

Erythropoietin (EPO) functions as a tissue-protective cytokine in addition to its crucial hormonal role in red cell production and neuron protection. This study aimed to determine the neuron protective effect of erythropoietin on experimental rats enduring spinal cord injury (SCI) by assessing thrombospondin-1 (TSP-1) level and transforming growth factor-beta (TGF-beta) in the development of a rat model of SCI.. Sixty Sprague-Dawley rats were randomly assigned to three groups: sham operation control group, SCI group and EPO treatment group. By using a weight-drop contusion SCI model, the rats in the SCI group and EPO treatment group were sacrificed at 24 hours and 7 days subsequently. The Basso, Beattie, and Bresnahan (BBB) scores were examined for locomotor function. Pathological changes were observed after HE staining. The expressions of thrombospondin-2 (TSP-1) and TGF-beta were determined by immunohistochemical staining and Western blotting.. Slighter locomotor dysfunction was discovered and it was recovered abruptly as higher BBB scores were found in the EPO treatment group than in the SCI group (P < 0.01). Pathologically, progressive disruption of the dorsal white matter and regeneration of a few neurons were also observed in SCI rats. TSP-1 and TGF-beta expression increased at 24 hours and 7 days after SCI in the injured segment, and it was higher in the SCI group than in the EPO treatment group. Spinal cord samples from the animals demonstrated a TSP-1 optical density of 112.2 +/- 6.8 and TSP-1 positive cells of 5.7 +/- 1.3 respectively. After injury, the TSP-1 optical density and cell number increased to 287.2 +/- 14.3/mm(2) and 23.2 +/- 2.6/mm(2) at 24 hours and to 232.1 +/- 13.2/mm(2) and 15.2 +/- 2.3/mm(2) at 7 days respectively. When EPO treated rats compared with the SCI rats, the TSP-1 optical density and cell number decreased to 213.1 +/- 11.6/mm(2) and 11.9 +/- 1.6/mm(2) at 24 hours and to 189.9 +/- 10.5/mm(2) and 9.3 +/- 1.5/mm(2) at 7 days, respectively (P < 0.01). In the SCI rats, the TGF-beta optical density and positive neuron number were 291.4 +/- 15.2/mm(2) and 28.8 +/- 4.9/mm(2) at 24 hours and 259.1 +/- 12.3/mm(2) and 23.9 +/- 4.1/mm(2) at 7 days respectively. They decreased in the EPO treated rats to 222.8 +/- 11.9/mm(2) and 13.7 +/- 2.1/mm(2) at 24 hours and to 196.5 +/- 9.7/mm(2) and 8.7 +/- 2.2/mm(2) at 7 days (P < 0.01).. Increased expression of TSP-1 and TGF-beta can be found in the injured segment of the spinal cord at 24 hours and 7 days after injury. EPO treatment can effectively prevent pathological alterations from severe spinal cord injury by reduced expression of TSP-1 and TGF-beta.

Topics: Animals; Blotting, Western; Disease Models, Animal; Erythropoietin; Female; Immunohistochemistry; Neuroprotective Agents; Random Allocation; Rats; Rats, Sprague-Dawley; Spinal Cord Injuries; Thrombospondin 1; Transforming Growth Factor beta

The accumulated knowledge of erythropoietin (EPO) interaction in neural injury has led to potentially novel therapeutic strategies. Previous experimental studies of recombinant human EPO (rhEPO) administration have shown favorable results after central and peripheral neural injury. In the present study we used the aneurysmal clip model to evaluate the efficacy of two different regimes of rhEPO administration on the functional outcome after severe acute spinal cord injury (ASCI).. Thirty rats were operated on with posterior laminectomy at thoracic 10th vertebra. Spinal cord trauma produced by extradural placement of the aneurysm clip, for 1 min. Animals were divided into three groups; the first group received a low total EPO dose (EPO-L), (2 doses of 1,000 IU each s.c.). The second group was administered the high total EPO dose (EPO-H), (14 doses of 1,000 IU each s.c.), and the third was the Control group, which received normal saline in the same time fashion with EPO-H group. Follow-up was for 6 weeks. Estimation of the functional progress of each rat was calculated using the locomotor rating scale of Basso et al, with a range from 0 to 21.. After surgery the animals suffered paraplegia with urinary disturbances. Rats that received EPO demonstrated statistically significant functional improvement compared to the Control group, throughout study interval. On the last follow-up at 6 weeks the EPO-L rats achieved a mean score 17.3 +/- 1.15, the EPO-H 14.7 +/- 1.82, and the control group 8.2 +/- 0.78. Comparison between the two EPO groups reveals superior final outcome of the group treated with lower total dose.. Our study supports current knowledge, that EPO administration has a positive effect on functional recovery after experimental ASCI. These data reflect the positive impact of EPO on the pathophysiologic cascade of secondary neural damage. However, we observed a dose-related effect on functional recovery. Interestingly, large doses do not seem to favor the neurological recovery as lower doses do.

Topics: Animals; Central Nervous System Agents; Disease Models, Animal; Dose-Response Relationship, Drug; Erythropoietin; Female; Rats; Rats, Wistar; Recombinant Proteins; Spinal Cord Injuries; Treatment Outcome

Aortic occlusion causes ischemia/reperfusion injury, kidney and spinal cord being the most vulnerable organs. Erythropoietin improved ischemia/reperfusion injury in rodents, which, however, better tolerate ischemia/reperfusion than larger species. Therefore, we investigated whether erythropoietin attenuates porcine aortic occlusion ischemia/reperfusion injury.. Before occluding the aorta for 45 mins by inflating intravascular balloons, we randomly infused either erythropoietin (n = 8; 300 IU/kg each over 30 mins before and during the first 4 hrs of reperfusion) or vehicle (n = 6). During aortic occlusion, mean arterial pressure was maintained at 80% to 120% of baseline by esmolol, nitroglycerine, and adenosine 5'-triphosphate. During reperfusion, noradrenaline was titrated to keep mean arterial pressure >80% of baseline. Kidney perfusion and function were assessed by fractional Na-excretion, p-aminohippuric acid and creatinine clearance, spinal cord function by lower extremity reflexes and motor evoked potentials. Blood isoprostane levels as well as blood and tissue catalase and superoxide dismutase activities allowed evaluation of oxidative stress. After 8 hrs of reperfusion, kidney and spinal cord specimens were taken for histology (hematoxylin-eosin, Nissl staining) and immunohistochemistry (TUNEL assay for apoptosis).. Parameters of oxidative stress and antioxidative activity were comparable. Erythropoietin reduced the noradrenaline requirements to achieve the hemodynamic targets and may improve kidney function despite similar organ blood flow, histology, and TUNEL staining. Neuronal damage and apoptosis was attenuated in the thoracic spinal cord segments without improvement of its function.. During porcine aortic occlusion-induced ischemia/reperfusion erythropoietin improved kidney function and spinal cord integrity. The lacking effect on spinal cord function was most likely the result of the pronounced neuronal damage associated with the longlasting ischemia.

Topics: Animals; Arterial Occlusive Diseases; Balloon Occlusion; Disease Models, Animal; Erythropoietin; Evoked Potentials, Motor; Female; Hemodynamics; Kidney Function Tests; Male; Oxidative Stress; Reperfusion Injury; Spinal Cord Injuries; Swine

This study was initiated due to an NIH "Facilities of Research--Spinal Cord Injury" contract to support independent replication of published studies that appear promising for eventual clinical testing. We repeated a study reporting the beneficial effects of recombinant human erythropoietin (rhEPO) treatment after spinal cord injury (SCI). Moderate thoracic SCI was produced by two methods: 1) compression due to placement of a modified aneurysm clip (20 g, 10 s) at the T3 spinal segment (n=45) [followed by administration of rhEPO 1000 IU/kg/IP in 1 or 3 doses (treatment groups)] and 2) contusion by means of the MASCIS impactor (n = 42) at spinal T9 (height 12.5 cm, weight 10 g) [followed by the administration of rhEPO 5000 IU/kg/IP for 7d or single dose (treatment groups)]. The use of rhEPO following moderate compressive or contusive injury of the thoracic spinal cord did not improve the locomotor behavior (BBB rating scale). Also, secondary changes (i.e. necrotic changes followed by cavitation) were not significantly improved with rhEPO therapy. With these results, although we cannot conclude that there will be no beneficial effect in different SCI models, we caution researchers that the use of rhEPO requires further investigation before implementing clinical trials.

Topics: Animals; Clinical Trials as Topic; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Erythropoietin; Female; Motor Activity; Neuroprotective Agents; Paralysis; Rats; Rats, Sprague-Dawley; Rats, Wistar; Reproducibility of Results; Spinal Cord; Spinal Cord Compression; Spinal Cord Injuries; Treatment Failure

Spinal cord injury (SCI) is a very destructive process for both patients and society. Lipid peroxidation is the main cause of the further secondary damage which starts after mechanical destruction of tissues. Recent studies have shown that erythropoietin (EPO) has neuroprotective properties. In this study, we aimed to see the effect of EPO treatment after spinal cord injury on the oxidant and anti-oxidant enzyme systems and the relationship with the N-methyl-D-Aspartate (NMDA) blockage. Spinal cord injury was produced by epidural compression with a cerebral vascular clip that has a closing force of 40 g for 30s after a limited multilevel laminectomy (T9-11). Experiment was done in 5 groups: Group 1: Sham-operated untraumatised, Group 2: SCI untreated, Group 3: 150 i.u./kg EPO injected i.p. at the end of the first hour following the trauma. Group 4: NMDA receptor antagonist ketamine (100mg/kg) i.p. Group 5: EPO+ketamine i.p. The experiments were finished after 12h of the trauma. The spinal cords were excised for biochemical examinations. Anti-oxidant enzymes; catalase and reduced glutathione (GSH) levels increased and lipid peroxidation product, malonyldialdehyde (MDA) level decreased in EPO treated group when compared to the other groups. TNF-alpha levels decreased in EPO treated group. Application of ketamine before EPO treatment decreased effects of EPO. In conclusion, our results suggest that 150 i.u./kg i.p. EPO, a therapeutic dose in anaemic patients, applied after 1h of spinal cord injury significantly attenuated the oxidative damage of spinal cord injuries in rats. This activity is abolished via ketamine pretreatment.

Topics: Analgesics; Animals; Antioxidants; Erythropoietin; Glutathione; Ketamine; Lipid Peroxidation; Malondialdehyde; N-Methylaspartate; Neuroprotective Agents; Oxidative Stress; Rats; Rats, Wistar; Spinal Cord Injuries; Spinal Cord Ischemia

Acute lesions of the spinal cord lead to dramatic changes in neuronal function. In the present study, we examined the possible involvement of neurotrophic factors in the action of the drug of choice for the treatment of such an emergency, i.e. the glucocorticoid methylprednisolone is compared to erythropoietin, a cytokine recently shown to markedly shorten the time necessary for motor recovery following injury [Gorio, A., Gokmen, N., Erbayraktar, S., Yilmaz, O., Madaschi, L., Cichetti, C., Di Giulio, A.M., Vardar, E., Cerami, A., Brines, M., 2002. Recombinant human erythropoietin counteracts secondary injury and markedly enhances neurological recovery from experimental spinal cord trauma. Proc. Natl. Acad. Sci. 99, 9450-9455]. We found that methylprednisolone reduces the lesion-enhanced Nerve Growth Factor (NGF) mRNA levels 3 h after injury in the trauma epicenter and caudal section of the cord whereas erythropoietin reinforced the NGF gene expression. Three days after the occurrence of the lesion, erythropoietin, but not methylprednisolone, significantly up-regulated the NGF gene expression both caudally and rostrally to the lesion site, an effect that, based on the chemo-attractant properties of neurotrophin, might facilitate the growth of injured axons toward NGF-rich sites and contribute to the enhancement of the regenerative process. The differences between the effects of methylprednisolone and erythropoietin dissipate 7 days after the lesion when they both enhance NGF mRNA levels at the epicenter. These data show that methylprednisolone and erythropoietin display a different pattern of activation of the neurotrophin NGF which is strictly dependent on the portion of the cord examined and the time elapsed from the injury. Based on our results, we suggest that the higher increase of NGF expression mediated by erythropoietin soon after the injury might explain, at least in part, the improved recovery of motor functions produced by erythropoietin compared to methylprednisolone and saline.

Topics: Animals; Erythropoietin; Gene Expression Regulation; Glucocorticoids; Methylprednisolone; Nerve Growth Factor; Rats; Rats, Sprague-Dawley; Recovery of Function; RNA, Messenger; Spinal Cord; Spinal Cord Injuries; Time Factors

Using a standardized rat model of contusive spinal cord injury (SCI; [Gorio A, Gokmen N, Erbayraktar S, Yilmaz O, Madaschi L, Cichetti C, Di Giulio AM, Vardar E, Cerami A, Brines M (2002) Recombinant human erythropoietin counteracts secondary injury and markedly enhances neurological recovery from experimental spinal cord trauma. Proc Natl Acad Sci U S A 99:9450-9455]), we previously showed that the administration of recombinant human erythropoietin (rhEPO) improves both tissue sparing and locomotory outcome. In the present study, to better understand rhEPO-mediated effects on chronic astrocyte response to SCI in rat, we have used immunocytochemical methods combined with confocal and electron microscopy to investigate, 1 month after injury, the effects of a single rhEPO administration on the expression of a) aquaporin 4 (AQP4), the main astrocytic water channel implicated in edema development and resolution, and two molecules (dystrophin and syntrophin) involved in its membrane anchoring; b) glial fibrillary acidic protein (GFAP) and vimentin as markers of astrogliosis; c) chondroitin sulfate proteoglycans of the extracellular matrix which are upregulated after SCI and can inhibit axonal regeneration and influence neuronal and glial properties. Our results show that rhEPO administration after SCI modifies astrocytic response to injury by increasing AQP4 immunoreactivity in the spinal cord, but not in the brain, without apparent modifications of dystrophin and syntrophin distribution. Attenuation of astrogliosis, demonstrated by the semiquantitative analysis of GFAP labeling, was associated with a reduction of phosphacan/RPTP zeta/beta, whereas the levels of lecticans remained unchanged. Finally, the relative volume of a microvessel fraction was significantly increased, indicating a pro-angiogenetic or a vasodilatory effect of rhEPO. These changes were consistently associated with remarkable reduction of lesion size and with improvement in tissue preservation and locomotor recovery, confirming previous observations and underscoring the potentiality of rhEPO for the therapeutic management of SCI.

Topics: Animals; Aquaporin 4; Astrocytes; Contusions; Dystrophin; Erythropoietin; Glial Fibrillary Acidic Protein; Gliosis; Immunohistochemistry; In Vitro Techniques; Indicators and Reagents; Male; Microscopy, Confocal; Microscopy, Immunoelectron; Motor Activity; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Spinal Cord Injuries; Vimentin

A number of drugs commonly used for a variety of clinical indications have been found recently to have substantial neuroprotective properties, raising the potential for rapid translation into human clinical trials of spinal cord injury (SCI). In this study we compared the neuroprotective efficacy of erythropoietin and a derivative of it, darbepoetin, in an acute model of thoracic SCI. Sprague-Dawley rats were randomized to receive erythropoietin (5000 IU/kg), darbepoetin (10 mug/kg), or saline, as a single intravenous injection 1 h after a thoracic contusion SCI. The animals were evaluated for behavioral recovery over 6 weeks, which included BBB locomotor testing, horizontal ladder testing, video-analysis of gait, and hindlimb monofilament sensory testing. At 6 week post-injury, the spinal cords were evaluated histologically to measure white and grey matter sparing at and around the epicenter of injury. We found that neither erythropoietin nor darbepoetin led to improved behavioral recovery over saline controls, with no significant differences observed in BBB scores, BBB subscores, footfall errors on horizontal ladder testing, width of hindlimb base of support, or threshold for paw withdrawal on sensory testing. Furthermore, no differences were observed in grey or white matter sparing between the three experimental groups. Using doses of erythropoietin and darbepoetin that other investigators have reported to be beneficial in SCI and stroke models, we were unable to demonstrate a neuroprotective effect when administered 1 h after injury. Further preclinical investigation is necessary to refine the treatment strategy of using erythropoietin or darbepoetin in acute spinal cord injury.

Topics: Analysis of Variance; Animals; Behavior, Animal; Darbepoetin alfa; Disease Models, Animal; Erythropoietin; Locomotion; Male; Neuroprotective Agents; Psychomotor Performance; Rats; Rats, Sprague-Dawley; Spinal Cord Injuries; Time Factors

Topics: Erythropoietin; Humans; Radiation Injuries; Radiation-Protective Agents; Radiotherapy; Spinal Cord; Spinal Cord Injuries

We investigated the effect of a single administration of recombinant human erythropoietin (rhEPO) on the preservation of the ventral white matter of rats at 4 weeks after contusive spinal cord injury (SCI), a time at which functional recovery is significantly improved in comparison to the controls [Gorio A, Necati Gokmen N, Erbayraktar S, Yilmaz O, Madaschi L, Cichetti C, Di Giulio AM, Enver Vardar E, Cerami A, Brines M (2002) Recombinant human erythropoietin counteracts secondary injury and markedly enhances neurological recovery from experimental spinal cord trauma. Proc Natl Acad Sci U S A 99:9450-9455; Gorio A, Madaschi L, Di Stefano B, Carelli S, Di Giulio AM, De Biasi S, Coleman T, Cerami A, Brines M (2005) Methylprednisolone neutralizes the beneficial effects of erythropoietin in experimental spinal cord injury. Proc Natl Acad Sci U S A 102:16379-16384]. Specifically, we examined, by morphological and cytochemical methods combined with light, confocal and electron microscopy, i) myelin preservation, ii) activation of adult oligodendrocyte progenitors (OPCs) identified for the expression of NG2 transmembrane proteoglycan, iii) changes in the amount of the chondroitin sulfate proteoglycans neurocan, versican and phosphacan and of their glycosaminoglycan component labeled with Wisteria floribunda lectin, and iv) ventral horn density of the serotonergic plexus as a marker of descending motor control axons. Injured rats received either saline or a single dose of rhEPO within 30 min after SCI. The results showed that the significant improvement of functional outcome observed in rhEPO-treated rats was associated with a better preservation of myelin in the ventral white matter. Moreover, the significant increase of both the number of NG2-positive OPCs and the labeling for Nogo-A, a marker of differentiated oligodendrocytes, suggested that rhEPO treatment could result in the generation of new myelinating oligodendrocytes. Sparing of fiber tracts in the ventral white matter was confirmed by the increased density of the serotonergic plexus around motor neurons. As for chondroitin sulfate proteoglycans, only phosphacan, increased in saline-treated rats, returned to normal levels in rhEPO group, probably reflecting a better maintenance of glial-axolemmal relationships along nerve fibers. In conclusion, this investigation expands previous studies supporting the pleiotropic neuroprotective effect of rhEPO on secondary degenerative response and its therapeutic pot

Topics: Animals; Antigens; Axons; Cell Membrane; Chondroitin Sulfate Proteoglycans; Erythropoietin; Male; Microscopy, Electron, Transmission; Myelin Proteins; Myelin Sheath; Nerve Fibers, Myelinated; Nerve Regeneration; Neural Pathways; Neuroprotective Agents; Nogo Proteins; Oligodendroglia; Proteoglycans; Rats; Rats, Sprague-Dawley; Recombinant Fusion Proteins; Serotonin; Spinal Cord; Spinal Cord Injuries; Stem Cells; Treatment Outcome; Wallerian Degeneration

Many neurologic disorders are accompanied by ischemic injury during the pathologic process. To develop a controllable and injury-specific gene therapy system for the neurologic disorders, we constructed a hypoxia inducible plasmid with the erythropoietin (Epo) 3' untranslated region (UTR), which can enhance the stability of target mRNAs in response to hypoxia. The Epo 3' UTR was inserted at the 3' flanking region of luciferase gene in pSV-Luc, resulting in the construction of pSV-Luc-EpoUTR. In pEpo-SV-Luc-EpoUTR, the Epo enhancer was inserted into the upstream of the SV40 promoter to increase the hypoxia inducibility. The plasmids were evaluated in N2a mouse neuroblastoma cells under hypoxic conditions and in a rat spinal cord injury (SCI) model. The results showed that the Epo 3' UTR alone showed a three-fold increase in luciferase activity in hypoxic N2a cells as well as in the rat SCI model when compared to the sham control. In contrast, the Epo 3' UTR showed no effect on the luciferase activity in the presence of the Epo enhancer, probably because the Epo enhancer was more sensitive to hypoxia and showed a dominant effect. However, the Epo enhancer itself showed high level of luciferase activity even in normoxia (about five to eight-folds increase), while the Epo 3' UTR did not show enhanced background activity. Immunohistochemical staining showed expression of luciferase from pSV-Luc-EpoUTR both in neurons and astrocytes around the injured spinal cord of rat. These results suggest that the Epo 3' UTR could provide a specific and safe system for the hypoxia-inducible gene therapy of the neurologic disorders including SCI.

Topics: 3' Untranslated Regions; Animals; Astrocytes; Cell Hypoxia; Cell Line, Tumor; Disease Models, Animal; Enhancer Elements, Genetic; Enzyme Activation; Erythropoietin; Gene Expression; Genetic Therapy; Genetic Vectors; Luciferases; Male; Mice; Neurons; Plasmids; Promoter Regions, Genetic; Rats; Rats, Sprague-Dawley; Simian virus 40; Spinal Cord Injuries; Spinal Cord Ischemia; Up-Regulation

Inflammatory response and apoptosis have been proposed as mechanisms of secondary injury of the spinal cord after primary insult. Recent studies have shown that erythropoietin (EPO) has neuroprotective properties. In this study, we assessed the efficacy of recombinant human erythropoietin (r-Hu-EPO) in the treatment of acute spinal cord injury (SCI) in rats. Rats were divided into five groups of eight rats each. Controls (Group 1) received laminectomy only. The trauma-only group (Group 2) underwent 40 g/cm contusion injury and had no medication. In group 3, 30 mg/kg of methylprednisolone (MPSS) was administered. Group 4 received 1000 IU/kg body weight of r-Hu-EPO. The vehicle group (Group 5) received a vehicle solution containing human serum albumin, which is the solvent for r-Hu-EPO. Twenty-four hours after trauma, animals were functionally evaluated and a spinal cord samples were obtained for the assessment of caspase-3 and myeloperoxidase (MPO) activities. The results showed that MPO and caspase-3 activities increased to statistically significant higher levels in the spinal cord after contusion injury comparing to the control group. MPO and caspase-3 enzyme activity levels were significantly reduced in animals treated either with r-Hu-EPO or MPSS. In addition, we observed significant early functional recovery in EPO-treated rats. EPO has anti-apoptotic and anti-inflammatory effects, and improves early clinical results after SCI.

Topics: Animals; Anti-Inflammatory Agents; Apoptosis; Caspase 3; Erythropoietin; Female; Humans; Methylprednisolone; Neuroprotective Agents; Peroxidase; Rats; Rats, Wistar; Recombinant Proteins; Recovery of Function; Spinal Cord Injuries

Erythropoietin protects many organs against the tissue injury and dysfunction caused by ischaemia/reperfusion and excessive inflammation. This editorial comment discusses the effects of erythropoietin in preclinical models of septic shock, endotoxemia, hemorrhagic shock, spinal cord trauma and zymosan-induced multiple organ failure.

Topics: Animals; Disease Models, Animal; Dose-Response Relationship, Drug; Endotoxemia; Erythropoietin; Mice; Multiple Organ Failure; Shock; Shock, Hemorrhagic; Shock, Septic; Spinal Cord Injuries; Treatment Outcome; Zymosan

The cytokine erythropoietin (EPO) has been shown to be neuroprotective in a variety of models of central and peripheral nervous system injury. Derivatives of EPO that lack its erythropoietic effects have recently been developed, and the initial reports suggest that they have a neuroprotective potential comparable to that of EPO. One such derivative is carbamylated EPO (CEPO). In the current study we compared the effects of treatment with EPO and CEPO on some of the early neurodegenerative events that occur following spinal cord injury (SCI) induced by hemisection. Adult male Wistar rats received a unilateral hemisection of the spinal cord. Thirty minutes and 24 h following injury, animals received an intraperitoneal injection of saline, EPO (40 microg/kg) or CEPO (40 microg/kg). Results indicated that 3 days post-injury, both CEPO and EPO decreased to a similar extent the size of the lesion compared with control animals. Both compounds also decreased the number of terminal transferase-mediated dUTP nick-end labelling (TUNEL)-labelled apopotic nuclei around the lesion site, as well as the number of axons expressing the injury marker beta-amyloid precursor protein. EPO and CEPO also increased Schwann cell infiltration into the lesion site, although neither compound had any effect on macrophage infiltration either within the lesion site itself or in the surrounding intact tissue. In addition, immunohistochemistry showed an increased expression of both the EPO receptor and the beta common receptor subunit, the components of the receptor complex proposed to mediate the neuroprotective effects of EPO and CEPO in neurons near the site of the injury. The results show that not only does CEPO have an efficacy comparable to that of EPO in its neuroprotective potential following injury, but also that changes in the receptors for these compounds following SCI may underlie their neuroprotective efficacy.

Topics: Animals; Axons; Erythropoietin; Image Processing, Computer-Assisted; Immunohistochemistry; In Situ Nick-End Labeling; Macrophages; Male; Neuroprotective Agents; Rats; Rats, Wistar; Receptors, Erythropoietin; Schwann Cells; Spinal Cord Injuries

Vascular endothelial growth factor (VEGF) has been investigated as a therapy for many disorders and injuries involving ischemia. In this report, we constructed and evaluated a hypoxia-inducible VEGF expression system as a treatment for spinal cord injury (SCI).. The hypoxia-inducible VEGF plasmid was constructed using the erythropoietin (Epo) enhancer with the Simian virus 40 (SV40) promoter (pEpo-SV-VEGF) or the RTP801 promoter (pRTP801-VEGF). The expression of VEGF in vitro was evaluated after transfection into N2A cells. The plasmids were then injected into rat spinal cords with contusion injuries. The expression of VEGF in vivo was measured using reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. Locomotor recovery in the rats was evaluated using the Basso, Beattie and Bresnahan (BBB) scale for locomotor analysis.. In vitro transfection showed that pEpo-SV-VEGF or pRTP801-VEGF induced VEGF expression under hypoxic conditions, whereas pSV-VEGF did not. The VEGF level was higher in the pEpo-SV-VEGF and pRTP801-VEGF groups than in the control group. The VEGF expression was detected in neurons and astrocytes of the spinal cord. Locomotor recovery was improved in the pEpo-SV-VEGF and pRTP801-VEGF groups, and BBB scores were higher than in the control group. Staining using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling showed that the number of apoptotic cells decreased in the plasmid-injected groups compared with the control group, and significant differences were observed between the hypoxia-responsive groups and the pSV-VEGF group.. These results suggest that the hypoxia-inducible VEGF expression system may be useful for gene therapy of SCI.

Topics: Animals; Apoptosis; Astrocytes; Cell Line, Tumor; Enhancer Elements, Genetic; Erythropoietin; Gene Expression; Genetic Therapy; Genetic Vectors; Hypoxia; Male; Mice; Motor Activity; Neurons; Plasmids; Rats; Rats, Sprague-Dawley; Simian virus 40; Spinal Cord; Spinal Cord Injuries; Transfection; Vascular Endothelial Growth Factor A

The study design was to decrease the damage of spinal cord on the experimentally induced acute spinal cord injury in rats. The objective of this study was to evaluate whether recombinant human erythropoietin (rHu-EPO) and methylprednisolone (MPSS) improve neurological function and histopathological changes if systemically administered after traumatic spinal cord injury. This study included 48 rats that underwent experimental SCI. Forty-eight animals were randomly divided into six groups. Animals constituted a moderate compression of 0.6 N that was produced by application of an aneurysm clip at level T3 for 1 min. rHu-EPO (1,000 and 3,000 U (Unit) per kg of body weight i.p.) and MPSS (30 mg/kg) were administered 5 min after injury, and control group was saline treated. (1) Control group (n=8), (2) MPSS group (n=8), (3) rHu-EPO 1,000 U group (n=8), (4) MPSS + rHu-EPO 1,000 U group (n=8), (5) rHu-EPO 3,000 U group (n=8), and (6) MPSS + rHu-EPO 3,000 U group (n=8). The neurological function and histopathology were evaluated at 24 and 72 h. According to the neurological functional test scores significant improvements between the control group and the other groups that had taken medical treatment were observed (P<0.001). Histopathologically severe ischemic findings were observed in the control group. A significant decrease in ischemic damage was detected in MPSS + rHu-EPO 3,000 U group (P<0.001). The most significant neurological functional and histopathological improvements were observed after systemical administration of MPSS + rHu-EPO 3,000 U and rHu-EPO 3,000 U. Furthermore, the MPSS + rHu-EPO 3,000 U group provides the most improved neurological functional and histopathological recovery.

Topics: Animals; Erythropoietin; Methylprednisolone; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Recovery of Function; Spinal Cord Compression; Spinal Cord Injuries

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.. The authors compared asialoEPO, a molecule that binds to the EPOR with high affinity but with a brief serum half-life (t1/2 < 2 minutes), to EPO to determine whether a single dose (10 microg/kg of body weight) administered by intravenous injection 24 hours before 1 minute of spinal cord compression provides benefit as determined by a 6-week assessment of neurological outcome and by histopathological analysis. Rats pretreated with asialoEPO or EPO and then subjected to a compressive injury exhibited improved motor function over 42 days, compared with animals treated with saline solution. However, pretreatment efficacy was substantially poorer than efficacy of treatment initiated at the time of injury. Serum samples drawn immediately before compression confirmed that no detectable asialoEPO remained within the systemic circulation. Western blot and immunohistochemical analyses performed using uninjured spinal cord 24 hours after a dose of asialoEPO exhibited a marked increase in glial fibrillary acidic protein, suggesting a glial response to EPO administration.. These results demonstrate that EPO and its analog do not need to be present at the time of injury to provide tissue protection and that tissue protection is markedly effective when either agent is administered immediately after injury. Furthermore, the findings suggest that asialoEPO is a useful reagent with which to study the dynamics of EPO-mediated neuroprotection. In addition, the findings support the concept of using a nonerythropoietic EPO derivative to provide tissue protection without activating the undesirable effects of EPO.

Topics: Analysis of Variance; Animals; Asialoglycoproteins; Blotting, Western; Disease Models, Animal; Erythropoietin; Immunoenzyme Techniques; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Receptors, Erythropoietin; Spinal Cord Injuries

Using a rat spinal cord injury (SCI) model, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL), anti-active caspase-3 antibody staining, histological examination, and histochemical studies were used to examine the antiapoptotic effect of erythropoietin.. To evaluate in detail the antiapoptotic effect of erythropoietin following SCI.. Although some investigators have reported antiapoptotic effects of erythropoietin using the TUNEL method, it has not been determined whether erythropoietin can prevent both acute neuronal death and secondary injury. Therefore, we examined the temporal and spatial effects of erythropoietin using TUNEL and active caspase-3 following SCI.. An in vitro study used a cerebrocortical culture in which the antiapoptotic effect of erythropoietin was examined after N-methyl-D-aspartate treatment. Using an in vivo study, rats with SCI received erythropoietin intraperitoneally, and were examined histologically and immunohistochemically with TUNEL, active caspase-3, and cell markers between 6 hours and 7 days after injury.. Cerebrocortical culture confirmed an antiapoptotic effect of erythropoietin. Erythropoietin treatment significantly decreased TUNEL-positive apoptotic neurons and oligodendrocytes as early as 6 hours after SCI in rats. This antiapoptotic effect was observed until 7 days after injury. In addition, erythropoietin treatment significantly decreased the number of active caspase-3 immunoreactive cells within the SCI. In the in vitro study, cerebrocortical culture confirmed an antiapoptotic effect of erythropoietin.. These findings suggest that exogenous erythropoietin decreases the number of apoptotic cells observed between the very early and subchronic stages following traumatic SCI.

Topics: Animals; Apoptosis; Cells, Cultured; Erythropoietin; Humans; Male; Mice; Mice, Inbred ICR; Neuroprotective Agents; Rats; Rats, Wistar; Recombinant Proteins; Spinal Cord; Spinal Cord Injuries

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.. 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 days in the spinal cord of injured and noninjured rats.. In noninjured spinal cord, weak immunohistochemical expression of EPO and EPO-R was observed in neuronal and glial cells as well as in endothelial and ependymal cells. In injured rats, a marked increase of expression of EPO and EPO-R was observed in neurons, vascular endothelium, and glial cells at 8 hours after injury, peaking at 8 days, after which it gradually decreased. Two weeks after injury, EPO immunoreactivity was scarcely detected in neurons, whereas glial cells and vascular endothelium expressed strong EPO-R immunoreactivity.. These observations suggest that the local EPO and EPO-R system is markedly engaged in the early stages after nervous tissue injury. The reduction in EPO immunoexpression and the increase in EPO-R staining strongly support the possible usefulness of a therapeutic approach based on exogenous EPO administration.

Topics: Aneurysm; Animals; Disease Models, Animal; Erythropoietin; Gene Expression Regulation; Male; Neurons; Rats; Rats, Sprague-Dawley; Receptors, Erythropoietin; Recombinant Proteins; Spinal Cord Compression; Spinal Cord Injuries

Inflammation plays a major pathological role in spinal cord injury (SCI). Although antiinflammatory treatment using the glucocorticoid methyprednisolone sodium succinate (MPSS) improved outcomes in several multicenter clinical trials, additional clinical experience suggests that MPSS is only modestly beneficial in SCI and poses a risk for serious complications. Recent work has shown that erythropoietin (EPO) moderates CNS tissue injury, in part by reducing inflammation, limiting neuronal apoptosis, and restoring vascular autoregulation. We determined whether EPO and MPSS act synergistically in SCI. Using a rat model of contusive SCI, we compared the effects of EPO [500-5,000 units/kg of body weight (kg-bw)] with MPSS (30 mg/kg-bw) for proinflammatory cytokine production, histological damage, and motor function at 1 month after a compression injury. Although high-dose EPO and MPSS suppressed proinflammatory cytokines within the injured spinal cord, only EPO was associated with reduced microglial infiltration, attenuated scar formation, and sustained neurological improvement. Unexpectedly, coadministration of MPSS antagonized the protective effects of EPO, even though the EPO receptor was up-regulated normally after injury. These data illustrate that the suppression of proinflammatory cytokines alone does not necessarily prevent secondary injury and suggest that glucocorticoids should not be coadministered in clinical trials evaluating the use of EPO for treatment of SCI.

Topics: Animals; Drug Interactions; Erythropoietin; Interleukin-6; Methylprednisolone Hemisuccinate; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Spinal Cord Injuries; Tumor Necrosis Factor-alpha

Erythropoietin is a hematopoietic growth factor. It is also involved in neurodevelopment and neuroprotection. The purpose of this study was to evaluate the effectiveness of erythropoietin in enhancing the neurological recovery following experimental spinal cord injury.. Rats were randomly divided into 4 groups. Group 1 received only laminectomy. Group 2, 3, and 4 have undergone a spinal contusion injury of 50 gr/cm. Group 2 received no medication. Group 3 received 30 mg/kg methylprednisolone. Group 4 received 5000 IU/kg recombinant human erythropoietin. Following injury, neurological recovery was evaluated for 14 days, using a swimming test.. At day 1, there was no difference between mean motor scores of group 2, 3, and 4. Following day 1, rats in group 4 exhibited a marked improvement in motor score, and this was maintained throughout the study. When compared to group 2, mean motor score of group 4 was significantly higher at day 4, 7, 10, and 14. When compared to group 3, mean motor score of group 4 was significantly higher at day 7, 10, and 14.. These findings suggest that erythropoietin enhances neurological recovery following spinal cord injury and it seems to be more effective than methylprednisolone at the given doses.

Topics: Animals; Disease Models, Animal; Erythropoietin; Humans; Male; Methylprednisolone; Motor Activity; Neurologic Examination; Neuroprotective Agents; Rats; Rats, Wistar; Recombinant Proteins; Recovery of Function; Spinal Cord Injuries; Time Factors

Lipid peroxidation has been reported to play an important role in spinal cord injury (SCI). Erythropoietin (EPO) is a hematopoietic growth factor that stimulates proliferation and differentiation of erythroid precursor cells and is also known to exert neurotrophic activity in the central nervous system. The purpose of this study was to investigate the effectiveness of recombinant human EPO in attenuating the severity of experimental SCI. Rats were divided into seven groups. Controls (1) received only laminectomy. The trauma-only group (2) underwent 50-g/cm contusion injury and had no medication. In group 3, 30 mg/kg of methylprednisolone was introduced. The vehicle group (4) received vehicle solution containing human serum albumin, which is a solvent of EPO. Groups 5, 6, and 7 received 100 IU/kg, 1,000 IU/kg, and 5,000 IU/kg of EPO, respectively. All treatments were given as single doses, intraperitoneally, immediately after injury. Thiobarbituric acid-reactive substances were estimated to demonstrate lipid peroxidation, and ultrastructure was evaluated by electron microscopy. The results showed that lipid peroxidation by-products increased after injury. Administration of EPO and methylprednisolone sodium succinate (MPSS) reduced thiobarbituric acid-reactive substances after trauma. The best biochemical results were obtained with 5,000 IU/kg of EPO. Electron microscopic findings showed that EPO protected the spinal cord from injury. Although 1,000 IU/kg and 5,000 IU/kg of EPO inhibited lipid peroxidation better than MPSS, ultrastructural neuroprotection was similar.

Topics: Acute Disease; Animals; Disease Models, Animal; Erythropoietin; Lipid Peroxidation; Male; Methylprednisolone; Neuroprotective Agents; Rats; Rats, Wistar; Spinal Cord; Spinal Cord Injuries; Thiobarbituric Acid Reactive Substances; Time Factors; Trauma Severity Indices

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 of in vivo and in vitro models. 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 beta receptor (betacR), the signal-transducing subunit shared by the granulocyte-macrophage colony stimulating factor, and the IL-3 and IL-5 receptors. However, because betacR knockout mice exhibit normal erythrocyte maturation, betacR is not required for erythropoiesis. We hypothesized that betacR in combination with the EpoR expressed by nonhematopoietic cells constitutes a tissue-protective receptor. In support of this hypothesis, membrane proteins prepared from rat brain, heart, liver, or kidney were greatly enriched in EpoR after passage over either Epo or CEpo columns but covalently bound in a complex with betacR. Further, antibodies against EpoR coimmunoprecipitated betacR from membranes prepared from neuronal-like P-19 cells that respond to Epo-induced tissue protection. Immunocytochemical studies of spinal cord neurons and cardiomyocytes protected by Epo demonstrated cellular colocalization of Epo betacR and EpoR. Finally, as predicted by the hypothesis, neither Epo nor CEpo was active in cardiomyocyte or spinal cord injury models performed in the betacR knockout mouse. These data support the concept that EpoR and betacR comprise a tissue-protective heteroreceptor.

Topics: Animals; Aorta; Cell Line; Cell Membrane; Cells, Cultured; Erythropoietin; Mice; Mice, Inbred C57BL; Mice, Knockout; Motor Activity; Protein Subunits; Receptors, Erythropoietin; Spinal Cord Injuries; Time Factors; Ventricular Function

Patients with hemoglobin greater than or equal to 100 g/L may have difficulty healing pressure ulcers because of impaired tissue oxygenation. Decreased hemoglobin is often anemia of chronic disease and may be due to the effects of inflammatory cytokines on erythroid progenitor cells. Recombinant human erythropoietin has been found to reverse anemia of chronic disease and may act as a growth factor in wound healing. To review the effect of 6 weeks of subcutaneous recombinant human erythropoietin 75 IU/kg administered 3 times weekly to resolve refractory anemia of chronic disease and heal Stage IV pressure ulcers, a retrospective chart review was conducted of four spinal cord injured patients (all men, mean age 59 years +/- 19) with Stage IV pressure ulcers and multiple comorbid conditions. The patients received recombinant human erythropoietin either through an inpatient spinal cord rehabilitation unit or an outpatient wound management clinic as part of interdisciplinary care. Mean hemoglobin increased from 88 +/- 7.4 g/L to 110 +/- 3.7 g/L. Mean ulcer surface area decreased from 42.3 cm2 (+/- 40.2) to 37.3 cm2 (+/- 44.3) despite extensive deroofing of one ulcer and subsequent increase in size. Mean ulcer depth decreased from 2.3 cm (+/- 1.2) to 1.2 cm (+/- 1.0). Human recombinant erythropoietin shows promise in resolving the refractory anemia of chronic disease associated with Stage IV pressure ulcers. Further study is suggested.

Topics: Adult; Aged; Anemia; Chronic Disease; Cost-Benefit Analysis; Drug Administration Schedule; Drug Costs; Erythropoietin; Hemoglobins; Humans; Injections, Subcutaneous; Male; Middle Aged; Pressure Ulcer; Recombinant Proteins; Retrospective Studies; Risk Factors; Severity of Illness Index; Spinal Cord Injuries; Treatment Outcome; Wound Healing

Topics: Animals; Disease Models, Animal; Erythropoietin; Glucocorticoids; Humans; Models, Neurological; Neurons; Neuroprotective Agents; Rats; Recovery of Function; Spinal Cord Injuries

The cytokine erythropoietin (EPO) possesses potent neuroprotective activity against a variety of potential brain injuries, including transient ischemia and reperfusion. It is currently unknown whether EPO will also ameliorate spinal cord injury. Immunocytochemistry performed using human spinal cord sections showed abundant EPO receptor immunoreactivity of capillaries, especially in white matter, and motor neurons within the ventral horn. We used a transient global spinal ischemia model in rabbits to test whether exogenous EPO can cross the blood-spinal cord barrier and protect these motor neurons. Spinal cord ischemia was produced in rabbits by occlusion of the abdominal aorta for 20 min, followed by saline or recombinant human (rHu)-EPO (350, 800, or 1,000 units/kg of body weight) administered intravenously immediately after the onset of reperfusion. The functional neurological status of animals was better for rHu-EPO-treated animals 1 h after recovery from anesthesia, and improved dramatically over the next 48 h. In contrast, saline-treated animals exhibited a poorer neurological score at 1 h and did not significantly improve. Histopathological examination of the affected spinal cord revealed widespread motor neuron injury associated with positive terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling in control but not in rHu-EPO-treated animals. These observations suggest both an acute as well as a delayed beneficial action of rHu-EPO in ischemic spinal cord injury. Because rHu-EPO is currently used widely with an excellent safety profile, clinical trials evaluating its potential to prevent motor neuron apoptosis and the neurological deficits that occur as a consequence of ischemic injury are warranted.

Topics: Animals; Apoptosis; Dose-Response Relationship, Drug; Erythropoietin; Humans; Immunohistochemistry; In Situ Nick-End Labeling; Ischemia; Male; Motor Neurons; Rabbits; Recombinant Proteins; Spinal Cord; Spinal Cord Injuries; Time Factors

Erythropoietin (EPO) functions as a tissue-protective cytokine in addition to its crucial hormonal role in red cell production. In the brain, for example, EPO and its receptor are locally produced, are modulated by metabolic stressors, and provide neuroprotective and antiinflammatory functions. We have previously shown that recombinant human EPO (rhEPO) administered within the systemic circulation enters the brain and is neuroprotective. At present, it is unknown whether rhEPO can also improve recovery after traumatic injury of the spinal cord. To evaluate whether rhEPO improves functional outcome if administered after cord injury, two rodent models were evaluated. First, a moderate compression of 0.6 N was produced by application of an aneurysm clip at level T3 for 1 min. RhEPO (1,000 units per kg of body weight i.p.) administered immediately after release of compression was associated with partial recovery of motor function within 12 h after injury, which was nearly complete by 28 days. In contrast, saline-treated animals exhibited only poor recovery. In the second model used, rhEPO administration (5,000 units per kg of body weight i.p. given once 1 h after injury) also produced a superior recovery of function compared with saline-treated controls after a contusion of 1 N at level T9. In this model of more severe spinal cord injury, secondary inflammation was also markedly attenuated by rhEPO administration and associated with reduced cavitation within the cord. These observations suggest that rhEPO provides early recovery of function, especially after spinal cord compression, as well as longer-latency neuroprotective, antiinflammatory and antiapoptotic functions.

Topics: Animals; Apoptosis; Disease Models, Animal; Erythropoietin; Female; Humans; Oligodendroglia; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Spinal Cord Injuries; Time Factors

Patients with spinal cord injury (SCI) have a high incidence of anemia. Intact erythropoietin (EPO) production is essential to the maintenance of erythrocyte mass and prevention and correction of anemia. However, the effect of chronic SCI on EPO production remains unclear. We measured plasma EPO concentration in 83 men with longstanding SCI and a group of normal able-bodied individuals. The SCI patients showed a significant reduction in hematocrit, a high prevalence of anemia, and an increased plasma EPO concentration. Active smokers showed a significantly higher hematocrit and lower EPO concentration than nonsmokers. No significant difference was found in hematocrit or EPO between individuals with paraplegia and those with quadriplegia. A negative correlation was found between EPO and hematocrit in SCI patients lacking significant lung disease. Thus, in the absence of renal insufficiency, EPO response to anemia is qualitatively preserved in SCI patients and is largely independent of the level of injury.

Topics: Adult; Analysis of Variance; Anemia; Enzyme-Linked Immunosorbent Assay; Erythropoietin; Humans; Male; Middle Aged; Regression Analysis; Spinal Cord Injuries

The origin of the temporary reduction in hematocrit and hemoglobin occurring after spinal cord injury (SCI) may be related to the neurologic dysfunction and to a change in erythropoietin (Ep) synthesis and/or secretion. Serum Ep, vital capacities, and numerous hematologic profiles were obtained in 12 cervical SCI patients during the first 12 weeks and 13th to 27th post-injury weeks, and in 8 thoracic SCI patients during the first 8 weeks and 9th to 28th weeks. Serum iron, iron binding, and saturation were obtained in 4 cervical SIC patients and blood gases in 10 patients with cervical SCI and in 6 with thoracic SCI. The results in all patients showed increased Ep values, returning to normal after 8 weeks in the thoracic SCI patients only. The few results on iron kinetics showed a tendency to low values, suggesting the necessity for further investigation. In an attempt to explain the Ep increase in SCI patients, the relative influence of the renal pelvic nerves and of the sympathetic nerves on its secretion, are examined.

Topics: Adolescent; Adult; Erythropoietin; Hematocrit; Hemoglobins; Humans; Male; Paraplegia; Quadriplegia; Spinal Cord Injuries; Vital Capacity