losartan-potassium and Status-Epilepticus

Status epilepticus triggers a mixture of apoptotic and necrotic cell death within the hippocampus. This neuronal loss may result in the development of epilepsy and cognitive deficits. Erythropoietin mediates a number of biological actions within the central nervous system and has been shown to be neuroprotective. In the present study, we investigated the effects of recombinant human erythropoietin on hippocampus of rat after lithium-pilocarpine induced status epilepticus. Twenty-one dam reared Wistar male rats, 21-day-old were divided into three groups: control group, lithium-pilocarpine induced status epilepticus and lithium-pilocarpine induced status epilepticus and erythropoietin treated group. Erythropoietin treated group received recombinant human erythropoietin 10 U/g intraperitoneally 40 min after pilocarpine injection for 5 days. Rats were sacrificed and brain tissues were collected at 5th day of experiment. Neuronal cell death and apoptosis were evaluated. Histopathological examination showed that erythropoietin significantly decreased neuronal cell death in CA1, CA2, CA3 and dentate gyrus regions of hippocampus. It also diminished apoptosis in the CA1 and dentate gyrus regions of hippocampus. In conclusion, erythropoietin may preserve the number of neurons and decrease apoptosis in model of status epilepticus induced by lithium-pilocarpine. This experimental study suggests that erythropoietin administration may be neuroprotective in status epilepticus.

Topics: Animals; Apoptosis; Convulsants; Erythropoietin; Hippocampus; Humans; In Situ Nick-End Labeling; Lithium; Male; Neurons; Neuroprotective Agents; Pilocarpine; Rats; Rats, Wistar; Recombinant Proteins; Status Epilepticus

This study examined the effect of recombinant human erythropoietin (r-HuEPO) on the serum levels of neuron-specific enolase (NSE), S-100β protein and myelin basic protein (MBP) in young rats 24 hrs after lithium-pilocarpine-induced status epilepticus (SE) in order to study the potential role of r-HuEPO in epileptic brain damage.. Forty 19-21-day-old male Sprague-Dawley (SD) rats were randomly divided into four groups (n=10): normal control group, SE, r-HuEPO pretreated-SE and r-HuEPO. SE was induced by lithium-pilocarpine. R-HuEPO (500 IU/kg) was intraperitoneally injected in the r-HuEPO pretreated-SE and r-HuEPO groups 4 hrs before SE. Serum levels of NSE, S-100β and MBP were determined 24 hrs after the SE event.. Serum levels of NSE, S-100β and MBP in the SE group increased significantly compared with those in the normal control and the r-HuEPO groups (P＜0.05). The r-HuEPO pretreated-SE group showed significantly decreased serum levels of NSE, S-100β and MBP compared with the SE group (P＜0.05).. r-HuEPO may reduce the expression of NSE, S-100β and MBP and thus might provide an early protective effect against epileptic brain injury.

Topics: Animals; Erythropoietin; Male; Myelin Basic Protein; Nerve Growth Factors; Phosphopyruvate Hydratase; Rats; Rats, Sprague-Dawley; Recombinant Proteins; S100 Calcium Binding Protein beta Subunit; S100 Proteins; Status Epilepticus

The design of peptide mimetics offers interesting opportunities to selectively include beneficial and exclude undesirable effects of a parent molecule. Epotris represents a novel erythropoietin mimetic, which lacks an erythropoietic activity. The present study evaluates the potential of this peptide to interfere with the histopathological consequences of electrical-induced status epilepticus in rats. The peptide attenuated status epilepticus-associated expansion of the neuronal progenitor cell population in a significant manner. Moreover, Epotris affected the number of persistent basal dendrites exhibited by neuronal progenitor cells. In contrast, hippocampal cell loss remained unaffected by administration of this peptide mimetic. Status epilepticus resulted in obvious microglial activation in different brain regions involved in seizure generation and spread. Epotris diminished the microglial response caused by prolonged seizure activity in the thalamus but not in other brain regions. The study renders support that the Epotris' sequences from binding site 2 in helix C of Epo play a role in receptor interaction and cytokine function. In addition, the data demonstrate that Epotris can exert limited in vivo effects on the cellular consequences of prolonged seizure activity. When considering further testing it should be taken in mind that Epotris administration only attenuated selected cellular consequences of status epilepticus and did not completely prevent cellular alterations.

Topics: Animals; Doublecortin Domain Proteins; Electric Stimulation; Electrodes, Implanted; Erythropoietin; Female; Microglia; Microtubule-Associated Proteins; Molecular Mimicry; Nerve Degeneration; Neural Stem Cells; Neurogenesis; Neuropeptides; Peptide Fragments; Rats; Rats, Sprague-Dawley; Status Epilepticus

The selection of a minimal active sequence of erythropoietin allowed the design of peptide mimetics that exert beneficial effects in the central nervous system but lack an erythropoietic effect. Erythropoietin has been suggested as a promising therapeutic and prophylactic for epilepsies based on its neuroprotective, neuroregenerative, and antiinflammatory potency. Therefore, it is of particular interest to evaluate whether the nonerythropoietic erythropoietin-derived peptide pHBSP can affect epileptogenesis.. In a post-status epilepticus model in rats, we determined the effects of pHBSP and of recombinant human erythropoietin with short-term administration following status epilepticus.. Both pHBSP and erythropoietin further enhanced the status epilepticus-associated increase in hippocampal cell proliferation. Thereby, pHBSP seemed to promote neuronal differentiation and survival resulting in a significant increase in neurogenesis. Neither pHBSP nor erythropoietin affected the number of animals exhibiting spontaneous recurrent seizures as well as the seizure frequency in the chronic phase. In the Morris water maze, pHBSP attenuated cognitive deficits in epileptic animals.. In conclusion, the helix B-derived erythropoietin peptide pHBSP can modulate the cellular and cognitive consequences of a status epilepticus. The impact of pHBSP on spatial learning might indicate that the peptide allows beneficial effects on epileptogenesis-associated cognitive deficits. However, it needs to be considered that learning deficits were not abolished by pHBSP and that the effects were not observed consistently until the end of the study. Therefore, adjustment of timing, duration, and dose of peptide administration might be necessary to further evaluate the efficacy of pHBSP.

Topics: Adaptation, Physiological; Analysis of Variance; Animals; Bromodeoxyuridine; Cell Proliferation; Cognition Disorders; Disease Models, Animal; Electric Stimulation; Erythropoietin; Exploratory Behavior; Female; Humans; Maze Learning; Microglia; Neurogenesis; Phosphopyruvate Hydratase; Rats; Rats, Sprague-Dawley; Serine Endopeptidases; Status Epilepticus

To observe the effect of recombinant human erythropoietin (rhuEPO) on p-Akt and caspase-9 expressions in the hippocampus of rats with status epilepticus (SE) and explore the neuroprotective mechanism of rhuEPO.. Adult male SD rats were randomized into control, PTZ, rHuEPO, LY294002 group, and DMSO groups and treated with normal saline (NS), PTZ, PTZ+rHuEPO, PTZ+LY294002+rHuEPO, and PTZ+DMSO+rHuEPO, respectively. The behavioral and electroencephalogram (EEG) changes of the rats were recorded, and the expressions of p-Akt and caspase-9 were detected using immunohistochemistry. The hippocampal expression of caspase-9 mRNA was detected using RT-PCR, and the expressions of Akt and p-Akt proteins were determined with Western blotting.. The p-Akt-positive cell and p-Akt protein expression increased significantly while the caspase-9-positive cell and caspase-9 mRNA expression decreased in rHuEPO group as compared with those in PTZ group (P<0.05). LY294002 treatment prior to rHuEPO injection significantly abolished the effects of rHuEPO on caspase-9 and p-Akt immunohistochemical positivity and caspase-9 mRNA and p-Akt protein expressions (P<0.05).. Administration of rHuEPO activates the PI3K/Akt signaling pathway in SE rats and increases the expression of p-Akt protein to regulate the expression of caspase-9, a regulatory factor of the mitochondrial-dependent apoptotic pathway, and therefore provides anti-apoptotic and neuroprotective effects.

Topics: Animals; Caspase 9; Erythropoietin; Hippocampus; Male; Neuroprotective Agents; Proto-Oncogene Proteins c-akt; Random Allocation; Rats; Rats, Sprague-Dawley; Recombinant Proteins; RNA, Messenger; Status Epilepticus

Selective neuronal loss is closely associated with cognitive impairments that occur following status epilepticus (SE). Our previous study suggested that erythropoietin (Epo) pre-treatment suppressed hippocampal neuronal death in rats after 1 h of SE convulsions. However, the underlying protective mechanism remained unclear. In the present study, we investigated the anti-apoptotic mechanism of Epo pre-treatment in the hippocampus using Li-pilocarpine-induced SE in rats. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining was performed to detect apoptosis and the Morris water maze was employed to assess spatial learning ability and to analyze the protective effects of Epo. Levels of Bcl-2 family (Bid, Bcl-2 and Bax) markers were examined via Western blot and immunofluorescence. We found that Epo pre-treatment prevented SE-induced cognitive impairments. The protection and cognitive effects were associated with higher levels of Bcl-2 and lower levels of Bax. The present results suggest that systemic Epo pre-treatment can confer neuroprotection following SE, and may provide novel insights into pathogenesis and treatment following SE injury.

Topics: Adaptor Proteins, Signal Transducing; Animals; Apoptosis; Apoptosis Regulatory Proteins; bcl-2-Associated X Protein; Cognition Disorders; Disease Models, Animal; Erythropoietin; Hippocampus; In Situ Nick-End Labeling; Male; Maze Learning; Muscarinic Agonists; Neuroprotective Agents; Pilocarpine; Rats; Rats, Sprague-Dawley; Status Epilepticus

Erythropoietin receptor (EpoR) binding mediates neuroprotection by endogenous Epo or by exogenous recombinant human (rh)Epo. The level of EpoR gene expression may determine tissue responsiveness to Epo. Thus, harnessing the neuroprotective power of Epo requires an understanding of the Epo-EpoR system and its regulation. We tested the hypothesis that neuronal expression of EpoR is required to achieve optimal neuroprotection by Epo. The ventral limbic region (VLR) in the rat brain was used because we determined that its neurons express minimal EpoR under basal conditions, and they are highly sensitive to excitotoxic damage, such as occurs with pilocarpine-induced status epilepticus (Pilo-SE). We report that (i) EpoR expression is significantly elevated in nearly all VLR neurons when rats are subjected to 3 moderate hypoxic exposures, with each separated by a 4-day interval; (ii) synergistic induction of EpoR expression is achieved in the dorsal hippocampus and neocortex by the combination of hypoxia and exposure to an enriched environment, with minimal increased expression by either treatment alone; and (iii) rhEpo administered after Pilo-SE cannot rescue neurons in the VLR, unless neuronal induction of EpoR is elicited by hypoxia before Pilo-SE. This study thus demonstrates using environmental manipulations in normal rodents, the strict requirement for induction of EpoR expression in brain neurons to achieve optimal neuroprotection. Our results indicate that regulation of EpoR gene expression may facilitate the neuroprotective potential of rhEpo.

Topics: Animals; Enzyme-Linked Immunosorbent Assay; Erythropoietin; Gene Expression Regulation; Hypoxia; Male; Neurons; Neuroprotective Agents; Pilocarpine; Rats; Rats, Sprague-Dawley; Receptors, Erythropoietin; Recombinant Proteins; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Status Epilepticus

Adult neural stem cells (NSCs) possess the potentials to self-renew and exert neuroprotection. In this study, we examined whether adult NSCs had anti-epileptic effects in rats with status epilepticus (SE) induced by kainic acid (KA) and whether co-administration of erythropoietin (EPO) enhanced anti-epileptic effects or cell survival. Adult NSCs were transplanted into KA-lesioned hippocampus with or without intracerebroventricular EPO infusion. Electronic encephalography (EEG) was recorded for 3 weeks after transplantation. The frequency of abnormal spikes in rats with NSC transplantation decreased significantly compared to those of rats without NSC transplantation. Most of the transplanted NSCs differentiated into GFAP-positive astrocytes. EPO infusion significantly enhanced the survival of NSCs, but not neuronal differentiation or migration. NSC transplantation increased the number of neuropeptide Y (NPY) and glutamic acid decarboxylase 67 (GAD67)-positive interneurons. NSC transplantation also suppressed mossy fiber sprouting into the inner molecular layer with subsequent reduction of hippocampal excitability, which finally prevented the development of spontaneous recurrent seizures in adult rats after KA-induced SE. This study might shed light on the cytoarchitectural mechanisms of temporal lobe epilepsy as well as clarify the effect of adult NSC transplantation with intracerebroventricular EPO infusion for temporal lobe epilepsy.

Topics: Action Potentials; Adult Stem Cells; Analysis of Variance; Animals; Cell Count; Cell Differentiation; Cell Movement; Cell Survival; Cells, Cultured; Combined Modality Therapy; Electroencephalography; Erythropoietin; Fluorescent Antibody Technique; Hippocampus; Infusion Pumps, Implantable; Interneurons; Kainic Acid; Male; Neural Inhibition; Neuronal Plasticity; Neurons; Rats; Rats, Inbred F344; Rats, Sprague-Dawley; Seizures; Signal Processing, Computer-Assisted; Status Epilepticus; Stem Cell Transplantation

Erythropoietin (EPO) has neuron and astroglial protective effects via reduction of tissue-injuring molecules such as reactive oxygen species, glutamate, inflammatory cytokines, and other damaging molecules. Although EPO may constitute an effective therapeutic modality in cases of epileptic insult, no study has been performed on the effects of exogenous EPO on the chronic seizure formation. In this study, we attempted to investigate if EPO could modulate the altered microenvironment in the epileptic rat brain.. Morphological changes in the hippocampi of rats subjected to lithium-pilocarpine-induced status epilepticus (SE) were examined with respect to neuronal loss, inflammation, blood-brain barrier (BBB) leakage, and cell genesis. Spontaneous recurrent seizures (SRSs) were investigated by long-term video-EEG monitoring.. EPO receptor (EPOR) was found to be increased in the hippocampus after SE. Administered EPO prevented, during the latent period following SE, BBB leakage, neuronal death, and microglia activation in the dentate hilus, CA1, and CA3, and inhibited the generation of ectopic granule cells in the hilus and new glia in CA1. Moreover, EPO reduced the risk of SRS development.. These findings suggest that EPO has a potential therapeutic role in the setting of acute epileptic insults.

Topics: Analysis of Variance; Animals; Brain; Bromodeoxyuridine; Capillary Permeability; CD11b Antigen; Cell Death; Disease Models, Animal; Electroencephalography; Erythropoietin; Fluorescein; Gene Expression Regulation; Homeodomain Proteins; Male; Neurons; Phosphopyruvate Hydratase; Pilocarpine; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Statistics, Nonparametric; Status Epilepticus; Tumor Suppressor Proteins

Neuroprotective functions of erythropoietin (Epo) are thought to involve a heteroreceptor composed of both Epo receptor (Epo-R) and common beta chain (betac). Here, we measured the response of hippocampal Epo system components (Epo, Epo-R and betac) during neurodegenerative processes following pilocarpine-induced status epilepticus (SE), and examined whether recombinant human Epo (rHuEpo) could support neuronal survival. We evidence that Epo is induced in astroglia following SE, in particular within areas displaying delayed neuronal death. In addition, we demonstrate for the first time that rHuEpo reduces considerably hippocampal neurodegeneration following SE. rHuEpo may thus supplement astroglial induction of Epo to promote enhanced hippocampal neuronal survival following SE. We also show that Epo-R is expressed by neurons and astrocytes mainly, while betac is barely detectable in basal conditions and induced in reactive microglia exclusively following SE. Altogether, our results suggest that Epo/rHuEpo exerts neuroprotection, through Epo-R signaling and independently of betac, and, therefore, may be anti-epileptogenic.

Topics: Animals; Anticonvulsants; Astrocytes; Cell Survival; Convulsants; Erythropoietin; Hippocampus; Macromolecular Substances; Male; Muscarinic Agonists; Neurons; Neuroprotective Agents; Pilocarpine; Protein Subunits; Rats; Rats, Sprague-Dawley; Receptors, Erythropoietin; Signal Transduction; Status Epilepticus

Status epilepticus (SE) is a grave condition in which the brain undergoes lasting seizures which can lead to neuronal loss. Our previous study suggested that preconditioning with erythropoietin (Epo) suppressed neuronal apoptosis in hippocampus of rats following SE in vivo by inhibiting caspase-3. In this study, we investigated the mechanisms by which Epo preconditioning may exert its anti-apoptotic effects using a lithium-pilocarpine induced SE model in rats. The effects of Epo on neuronal cell death were evaluated using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), and the role of the Bcl-2 protein family, which have been shown to be anti- (Bcl-2, Bcl-w) or pro- (Bid, Bim) apoptotic, was examined with immunofluorescence. We found Epo preconditioning decreased the total number of TUNEL, Bim and Bid positive cells, but increased the total number of Bcl-w and Bcl-2 positive cells. These results suggest that systemic Epo pretreatment protects neurons in an acute phase of SE and may result in further suppression of neuronal apoptosis in hippocampus by regulating the balance between pro- and anti-apoptotic Bcl-2 family proteins.

Topics: Analysis of Variance; Animals; Apoptosis Regulatory Proteins; Bcl-2-Like Protein 11; BH3 Interacting Domain Death Agonist Protein; Cell Count; Cell Death; Disease Models, Animal; Drug Interactions; Erythropoietin; In Situ Nick-End Labeling; Indoles; Male; Membrane Proteins; Neurons; Neuroprotective Agents; Pilocarpine; Proto-Oncogene Proteins; Rats; Rats, Sprague-Dawley; Status Epilepticus

Selective neuronal loss following status epilepticus (SE) was first described just under 100 years ago. The acute pathology following SE was shown to be 'ischemic cell change' and was assumed to arise through hypoxia/ischemia. Recently, erythropoietin (Epo) has been shown to have potent anti-apoptosis activity in central nervous system neurons in animal models of ischaemic injury.. In this report, in order to determine Epo preconditioning on hippocampus neuronal apoptosis, we examined caspase-3 expression following SE caused by Li-pilocarpine in rats.. Animals were classified into three groups: EP group (pilocarpine group), rhEpo-pilocarpine group and control group. Four hours after preconditioning with Epo intraperitoneally, pilocarpine hydrochloride was administered intraperitoneally and observed for behavioral manifestations of SE. The animals were sacrificed at one hour after SE onset.. At the above-mentioned time point, animals were deeply anesthetized and were perfused through the left ventricle. Detection of hippocampus neuronal apoptosis was performed with caspase-3 immunohistochemical technique on three groups. To further confirm which cell population upregulates caspase-3, brain sections were stained for NeuN (green) and caspase-3 (red).. ANOVA and Fisher's post hoc test was used.. Quatification of hippocampus neurons revealed that the number of caspase-3-positive cells in the CA1/CA3 area and dentate gyrus(DG) of three groups had a significant difference. In comparison with control group, there was an increase by 74% and 534%, 42% and 272% in the CA1/CA3 area and DG of EP group and rhEpo-treated group respectively. There was a decrease by 18% and 26% in the CA1/CA3 area and DG of rhEpo-treated group compared with those in EP group. In addition, colocalization of caspase-3 with NeuN was shown.. Systemic rhEpo therapy reduced caspase-3 expression in SE induced by Li-pilocarpine.

Topics: Animals; Apoptosis; Caspase 3; Caspase Inhibitors; Caspases; Cysteine Proteinase Inhibitors; Disease Models, Animal; Erythropoietin; Hippocampus; Male; Neurons; Pilocarpine; Rats; Rats, Sprague-Dawley; Status Epilepticus

Topics: Adult; Blood Pressure; Erythropoietin; Humans; Hypertension; Male; Recombinant Proteins; Status Epilepticus