OBJECTIVETo evaluate the effect of early application of recombinant human erythropoietin (rhEPO) on white matter development in preterm infants using fractional anisotropy (FA) of magnetic resonance diffusion tensor imaging (DTI).

METHODSA total of 81 preterm infants with gestational age ≤32 weeks, birth weight <1 500 g, and hospitalization within 24 hours after birth were randomly divided into rhEPO group (42 infants) and control group (39 infants). The infants in the rhEPO group were administered rhEPO, while those in the control group were given the same volume of normal saline. The preterm infants of both groups took examinations of head magnetic resonance imaging, diffusion-weighted imaging, and DTI at the corrected gestational age of 35-37 weeks. FA was calculated for the regions of interest in both groups.

RESULTSThere was no significant difference in the incidence of intracranial hemorrhage, periventricular leukomalacia, focal cerebral white matter damage (CWMD), and extensive CWMD between rhEPO and control groups (P>0.05). Compared with the control group, the rhEPO group showed higher FA values at the posterior limb of the internal capsule, the splenium of the corpus callosum, frontal white matter, and occipital white matter (P<0.05). There was no significant difference in FA values at the parietal white matter, thalamus, lenticular nucleus, and caudate nucleus between the two groups (P>0.05).

CONCLUSIONSEarly application of rhEPO has a neuroprotective effect on white matter development in preterm infants.

Diffusion Tensor Imaging ; Erythropoietin ; pharmacology ; Female ; Humans ; Infant, Newborn ; Infant, Premature ; Male ; Neuroprotective Agents ; pharmacology ; Recombinant Proteins ; pharmacology ; White Matter ; drug effects ; growth & development

OBJECTIVETo explore the impacts of erythropoietin on vascular endothelial growth factor receptor 2 (VEGFR2) by the extracellular signal-regulated kinase (ERK) signaling pathway in a neonatal rat model of periventricular white matter damage.

METHODSAll of postnatal day 4 rats were randomized into three groups: the sham group [without hypoxia-ischemia (HI)], the HI group (HI with saline administration), and the erythropoietin (EPO) group [HI with recombinant human erythropoietin (rh-EPO) administration]. Rat pups underwent permanent ligation of the right common carotid artery, followed by 6% O2 for 2 hours or sham operation and normoxic exposure. Immediately after the HI, rats received a single intraventricular injection of rh-EPO (0.6 IU/g body mass) or saline. ERK and phosphorylation-ERK were examined at 60 minutes and 90 minutes after operation, and VEGFR2 were detected at 2 and 4 days after operation by using Western blot.

RESULTSAt 60 minutes and 90 minutes after operation, the proteins of phosphorylation-ERK were significantly higher in HI rats than in the sham rats and significantly higher in HI+EPO rats than in the HI rats (P<0.05). Two days after operation, VEGFR2 was not significantly different between sham and HI rats. However, the proteins of VEGFR2 were increased after administration of rh-EPO (P<0.05). Four days after operation, the proteins of VEGFR2 were significantly higher in HI rats than in the sham rats and significantly higher in HI+EPO rats than in the HI rats (P<0.05).

CONCLUSIONEPO may regulate VEGFR2 expression by affecting the intracranial ERK signaling pathways.

Animals ; Animals, Newborn ; Disease Models, Animal ; Erythropoietin ; pharmacology ; Humans ; Hypoxia-Ischemia, Brain ; physiopathology ; MAP Kinase Signaling System ; Phosphorylation ; Rats ; Rats, Sprague-Dawley ; Recombinant Proteins ; pharmacology ; Vascular Endothelial Growth Factor Receptor-2 ; metabolism ; White Matter ; physiopathology

OBJECTIVETo explore the effect of recombinant human erythropoietin (rhEPO) on expression of brain-derived neurotrophic factor (BDNF) in different brain regions of aging rats.

METHODSForty male SD rats were randomized equally into negative control group, D-galactose group, EPO treatment group, and positive control group. Rat models of subacute aging were established by continuous subcutaneous injection of 5% D-galactose. Immunohistochemical staining was used to analyze the variation of BDNF expressions in different brain regions of the aging rats with different treatments.

RESULTSSignificant brain region-specific differences in BDNF expression were found among the rats in different groups. Compared with those in the negative control group, the numbers of BDNF-positive cells in the hippocampal CA1 region, CA3 region, dentate gyrus (DG) and frontal cortex were all decreased obviously in D-galactose group (P<0.05) but increased in both EPO group and the positive control group (P<0.05) without significant differences between the latter two groups. In the rats in the same group, the number of BDNF-positive cells varied markedly in different brain regions (P<0.05), and the expression level of BDNF was the highest in the frontal cortex followed by the hippocampal CA3 region and the dentate gyrus, and was the lowest in the hippocampal CA1 region.

CONCLUSIONTreatment with rhEPO enhances the expression of BDNF in rat neural cells, suggesting that rhEPO may protect the nervous system from aging by regulating the BDNF pathway.

Aging ; Animals ; Brain-Derived Neurotrophic Factor ; metabolism ; CA1 Region, Hippocampal ; metabolism ; CA3 Region, Hippocampal ; metabolism ; Dentate Gyrus ; metabolism ; Erythropoietin ; pharmacology ; Frontal Lobe ; metabolism ; Galactose ; Humans ; Male ; Neurons ; drug effects ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Recombinant Proteins ; pharmacology

Amounts of researches show that EPO is characterized with neurotrophic and neuroprotective manner, especially in brain stroke, which attracts a large numbers of researchers to study it. With the accumulating researches on its neuroprotection, many related mechanisms were revealed, such as antioxidant, anti-apoptosis, angiogenesis, anti-inflammatory, which suggests a multiple targets role of EPO on brain stroke. However, because of the high risk of thromboembolism in clinical administration of rhEPO and its analogs, the herbs are potential to be a replacer for its less side effects. Many researchers suggested that a larger of herbs were founded having the action of increasing the endogenous EPO in the model of anemia and cerebral ischemia. At the same time, there herbs were also proved that they had the action of against cerebral ischemia while some without considering the role of EPO in the reports. Considering of the action of promoting EPO of these herbs and the neural protection of EPO, this essay mainly summarizes the studies of herbs promoting EPO in the cerebral ischemia and discusses the mechanism of regulating the EPO of these herbs, for the aim of finding the potential drugs against cerebral ischemia.
Animals ; Brain Ischemia ; drug therapy ; genetics ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Erythropoietin ; genetics ; metabolism ; Humans ; Neuroprotection ; drug effects ; Plants, Medicinal ; chemistry

OBJECTIVETo investigate the protective effect and action mechanism of petroleum ether extracts from Saussurea involucrate on brain tissues of hypoxia rats under constant pressure and closed conditions.

METHODThe PESI dosage-dependent experiment for hypoxia rats was conducted under constant pressure and closed conditions by intraperitoneally injecting 125, 250, 500 mg x kg(-1) to finalize that the optimum dosage is the high dose of PESI. Afterwards, 90 Wistar rats were randomly divided into the hypoxic model group, the acetazolamide 250 mg x kg(-1) group and the PESI high dose group. Each group was further divided into three subgroups according to different hypoxia times, with 10 rats in each subgroup. Under the same hypoxia and administration conditions, the rats were sacrificed after 0, 3, 6 h respectively. Their brain samples were collected for common pathological observation and immunohistochemical staining of HIF-1alpha. Real-time RT-PCR was used to detect HIF-1alpha, EPO, HO-1 and Caspase-3 gene expressions. And the Western blot assay was adopted to detect HIF-1alpha protein expression.

RESULTThe brain tissues of the hypoxia model group were severely damaged with the increase in the hypoxia time. The acetazolamide group and the PESI high does group were damaged in a much lower degree. According to the gene expression and the Western blot assay, high dose of PESI could inhibit HIF-1alpha expression. According to the pure gene expression test, high dose of PESI could increase EPO and HO-1 mRNA expressions, but inhibit Caspase-3 mRNA expression.

CONCLUSIONPESI's protective mechanism for brain tissues of hypoxia rats under constant pressure and closed conditions may be related to its effects in inhibiting HIF-1alpha expression, increasing EPO expression and resisting cell apoptosis.

Alkanes ; chemistry ; Animals ; Brain ; cytology ; drug effects ; metabolism ; Caspase 3 ; genetics ; Cell Hypoxia ; drug effects ; Cytoprotection ; drug effects ; Dose-Response Relationship, Drug ; Drugs, Chinese Herbal ; pharmacology ; Erythropoietin ; genetics ; Gene Expression Regulation, Enzymologic ; drug effects ; Heme Oxygenase-1 ; genetics ; Hypoxia-Inducible Factor 1, alpha Subunit ; genetics ; metabolism ; Male ; Rats ; Rats, Wistar ; Saussurea ; chemistry

OBJECTIVETo investigate the effects of erythropoietin (EPO) on the neuronal proliferation and apoptosis in neonatal rats after infection-induced brain injury and the neuroprotective mechanism of EPO in neonatal rats with infection-induced brain injury.

METHODSTwenty-six two-day-old neonatal rats were randomly divided into 3 groups: control group (intraperitoneally given an equal volume of normal saline), lipopolysaccharide (LPS) group (intraperitoneally given LPS 0.6 mg/kg), and EPO group (intraperitoneally given LPS 0.6 mg/kg and EPO 5 000 U/kg). These groups were injected with respective drugs for 5 consecutive days. Meanwhile, each group was intraperitoneally injected with 5-bromo-2'-deoxyuridine (BrdU) (50 mg/kg) once a day for 5 consecutive days. The expression of BrdU and cleaved Caspase-3 in the hippocampal dentate gyrus was detected by immunohistochemistry at 24 hours after the last injection.

RESULTSThe number of neuronal cells in the hippocampal dentate gyrus in the LPS and EPO groups was significantly greater than in the control group (P<0.05), but there was no significant difference between the LPS and EPO groups. The EPO group had a significantly higher number of BrdU-positive cells in the subgranular zone of hippocampal dentate gyrus than the LPS group (51±9 vs 29±6; P<0.05), but a significantly lower number of BrdU-positive cells than the control group (51±9 vs 67±12; P<0.05). The EPO group had a significantly lower number of cleaved Caspase-3-positive cells in the subgranular zone of hippocampal dentate gyrus than the LPS group (27.9±1.5 vs 34.0±1.3; P<0.05), but a significantly higher number of cleaved Caspase-3-positive cells than the control group (27.9±1.5 vs 21.0±1.7; P<0.05).

CONCLUSIONSEPO can promote hippocampal neuronal proliferation and reduce neuronal apoptosis in neonatal rats after infection-induced brain injury.

Animals ; Animals, Newborn ; Apoptosis ; drug effects ; Brain Diseases ; drug therapy ; pathology ; Bromodeoxyuridine ; metabolism ; Caspase 3 ; metabolism ; Cell Proliferation ; drug effects ; Erythropoietin ; pharmacology ; therapeutic use ; Hippocampus ; pathology ; Neurons ; pathology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study the effects of erythropoietin (EPO) on serum levels of neuron-specific enolase (NSE) and S-100B in neonates with hypoxic-ischemic encephalopathy (HIE) and the underlying mechanism.

METHODSForty neonates with HIE were randomly divided into conventional treatment (n=20) and EPO treatment groups (n=20). Twenty healthy full-term neonates born during the same period were randomly selected as the normal control group. The conventional treatment group received conventional treatment, while the EPO treatment group received conventional treatment as well as EPO [200 IU/(kg.d)] which was given by intravenous infusion from the second day after birth. The course of treatment was 7 days. Blood samples of the three groups were collected on the first day after birth (before treatment) and the ninth day after birth (after treatment). Serum levels of NSE and S-100B were measured by double-antibody sandwich ABC-ELISA.

RESULTSBefore treatment, the two treatment groups had significantly higher serum NSE and S-100B levels than the normal control group (P<0.01), whereas no significant differences in the levels of NSE and S-100B were observed between the conventional treatment and EPO treatment groups (P>0.05). The serum NSE and S-100B levels on the ninth day after birth were significantly lower than those on the first day after birth in the three groups (P<0.01). After treatment, the serum NSE and S-100B levels were significantly lower in the EPO treatment group than in the conventional treatment group (P<0.05).

CONCLUSIONSDynamic monitoring of serum NSE and S-100B levels may be helpful for the early diagnosis of HIE and the assessment of brain injury repair in newborns with HIE. EPO may be helpful for the repair of neurons and glial cells.

Erythropoietin ; pharmacology ; Female ; Humans ; Hypoxia-Ischemia, Brain ; blood ; Infant, Newborn ; Male ; Phosphopyruvate Hydratase ; blood ; S100 Calcium Binding Protein beta Subunit ; blood

OBJECTIVETo investigate the effect and mechanism of recombinant human erythropoietin (rhEPO) on angiogenesis in chronic ischemic porcine myocardium.

METHODSA ameroid constrictor was placed around the proximal circumflex branch of the left coronary artery in 12 Bama miniatures' swine artery by thoracoscopy. Electrocardiogram and coronary angiography were used to confirm the establishment of myocardial ischemia. The animals were divided into rhEPO treatment group (n = 6) and negative control group (n = 6). Treatment group received subcutaneous injection of rhEPO at 1, 3, 7, 14, 21 days, control group received saline. The expression of vascular endothelial growth factor (VEGF) in serum was assessed by ELISA. Ultrasonography and coronary angiography were assessed 28 days after therapy. Western blot was used to detect the expression of VEGF, phosphorylated protein kinase B (p-Akt) and phosphorylated extracellular signal regulated kinases (p-Erk). The degree of angiogenesis was assessed by immunohistochemical analysis.

RESULTSSerum VEGF rose significantly in both control and treatment groups, peaking at 3 days and then returning to the near-baseline level at 28 days, but the two groups showed no significant difference at each time point (P > 0.05). Echocardiographic measurements showed that the left ventricular systolic function of animals in treatment group increase significantly after rhEPO therapy. the expression levels of VEGF, p-Akt and p-Erk had markedly increased, which resulted in a 2.5-fold increased of VEGF, 1.1-fold increased of p-Akt, 1.5-fold increased of p-Erk (t = 37.721, 10.907, 12.957, all P = 0.000). there were significant increase in capillary density and arteriole density in the two groups ((944 ± 98) %/mm² vs. (569 ± 102) %/mm², (73 ± 13) %/mm² vs. (45 ± 10) %/mm², t = 4.214, 2.869, P = 0.016, 0.023).

CONCLUSIONSrhEPO can promote angiogenesis and arteriogenesis and improve the left ventricular systolic function in porcine model of chronic myocardial ischemia. The potential mechanism is to up-regulated the expression of p-Akt and p-Erk.

Animals ; Disease Models, Animal ; Epoetin Alfa ; Erythropoietin ; pharmacology ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; Humans ; Male ; Myocardial Ischemia ; drug therapy ; metabolism ; pathology ; Neovascularization, Physiologic ; drug effects ; Proto-Oncogene Proteins c-akt ; metabolism ; Recombinant Proteins ; pharmacology ; Swine ; Swine, Miniature ; Vascular Endothelial Growth Factor A ; metabolism

The protective effect of erythropoietin (EPO) on tissues following ischemia and reperfusion injuries remains poorly understood. We aimed to investigate the effect of EPO in preventing endotoxin-induced organ damage. Rat model of multiple organ failure (MOF) was established by tail vein injection of 10 mg/kg lipopolysaccharide (LPS). Recombinant human EPO treatment (5000 U/kg) was administered by tail vein injection at 30 min after LPS challenge. Twenty-four h after EPO treatment, changes in serum enzyme levels, including aspartate aminotransferase (AST), alanine transaminase (ALT), blood urea nitrogen (BUN) and creatinine (Cr), were evaluated by biochemical analysis. Serum levels of tumor necrosis factor-α (TNF-α) were determined by using immunoradiometric assay. Histological examination of tissue sections was carried out by hematoxylin and eosin staining, while ultrastructure evaluation of organ tissues was assessed by transmission electron microscopy. Protein expression levels were detected by using Western blotting. EPO treatment showed a modest effect in preventing LPS-induced elevation of AST, ALT, BUN, Cr, and TNF-α levels, and in protecting against LPS-induced tissue degeneration and injured ultrastructure in the lung, liver, and kidney. Moreover, LPS promoted phosphorylation of alanine aminotransferase (AKT) and increased nuclear factor-κB (NF-κB) activation in the lung, liver, and kidney (P<0.05 vs. control). However, EPO treatment significantly decreased the LPS-induced pAKT up-regulation in these tissues (P<0.05 vs. LPS treatment alone). The present study demonstrates that EPO may play a protective role against LPS-induced MOF by reducing the inflammatory response and tissue degeneration, possibly via the phosphatidylinositol 3-kinase/AKT and NF-κB signaling pathways.
Alanine Transaminase ; blood ; Animals ; Aspartate Aminotransferases ; blood ; Blood Urea Nitrogen ; Blotting, Western ; Creatinine ; blood ; Endotoxins ; Erythropoietin ; administration & dosage ; genetics ; pharmacology ; Injections, Intravenous ; Kidney ; drug effects ; metabolism ; ultrastructure ; Lipopolysaccharides ; Liver ; drug effects ; metabolism ; ultrastructure ; Lung ; drug effects ; metabolism ; ultrastructure ; Male ; Microscopy, Electron, Transmission ; Multiple Organ Failure ; blood ; chemically induced ; prevention & control ; NF-kappa B ; metabolism ; Phosphorylation ; drug effects ; Proto-Oncogene Proteins c-akt ; metabolism ; Rats ; Rats, Wistar ; Recombinant Proteins ; administration & dosage ; pharmacology ; Tumor Necrosis Factor-alpha ; blood

OBJECTIVETo study the effect of erythropoietin (EPO) on the activities of antioxidant enzymes, namely catalase (CAT) and glutathione peroxidase (GSH-Px) in the brain tissues of aged rats.

METHODSThirty SD rats were randomly divided into normal control, aging model, and recombinant human erythropoietin (rhEPO) treatment groups (n=10). Morris water maze was used to compare the behavioral indexes. The rats were then sacrificed to observe Nissl bodies in the hippocampal neurons with Nissl staining and test the activities of CAT and GSH-Px in the brain tissues.

RESULTSCompared with the control group, the aging rats showed significantly deteriorated learning and memory abilities (P<0.05), which were improved obviously by rhEPO treatment (P<0.05). The number of Nissl bodies in the neurons was reduced in the aging rats compared with that in the control group, and rhEPO treatment increased the number of Nissle bodies but failed to restore the control level. The aging rats also showed significantly lowered activities of CAT and GSH-Px in the brain tissue (P<0.05), which were increased significantly after rhEPO treatment (P<0.05).

CONCLUSIONEPO can enhance the activities of the antioxidant enzymes in the brain tissues of aged rats to increase the antioxidant capacity and produces an anti-aging effect.

Aging ; Animals ; Brain ; enzymology ; Catalase ; metabolism ; Epoetin Alfa ; Erythropoietin ; pharmacology ; Glutathione Peroxidase ; metabolism ; Learning ; drug effects ; Male ; Memory ; drug effects ; Nissl Bodies ; drug effects ; Rats ; Rats, Sprague-Dawley ; Recombinant Proteins ; pharmacology