epoetin-alfa has been researched along with Disease-Models--Animal* in 41 studies
4 review(s) available for epoetin-alfa and Disease-Models--Animal
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Erythropoiesis-stimulating agents: favorable safety profile when used as indicated.
Several studies with erythropoiesis-stimulating agents (ESAs) have raised a number of safety issues. Therefore, a discussion of available data in light of the current EORTC guidelines 2006 on the use of ESAs in anemic patients is warranted.. Literature is reviewed with respect to experimental and clinical data on the effect of ESA therapy on tumor growth both in the preclinical setting and on patient survival.. Studies showing an adverse effect of ESA therapy on patient survival generally exhibit considerable methodological deficiencies. Moreover, they investigated treatment situations for which ESAs are not approved and/or did not involve recommended baseline ("intervention") or target hemoglobin levels.. When used as indicated, ESAs are valuable and safe drugs for the treatment of anemia and do not negatively affect patient survival. In particular, the data situation confirms the importance and correctness of the EORTC guidelines 2006 and their recently updated version. It is therefore recommended that these guidelines continue to be strictly followed in the treatment of chemotherapy-induced anemia. Topics: Adult; Anemia; Animals; Antineoplastic Agents; Blood Transfusion; Clinical Trials as Topic; Clinical Trials, Phase II as Topic; Disease Models, Animal; Disease Progression; Epoetin Alfa; Erythropoietin; Female; Hematinics; Hemoglobins; Humans; Male; Meta-Analysis as Topic; Mice; Neoplasms; Neoplasms, Experimental; Oxygen; Practice Guidelines as Topic; Prospective Studies; Randomized Controlled Trials as Topic; Rats; Receptors, Erythropoietin; Recombinant Proteins; Risk Factors; Safety; Tumor Cells, Cultured | 2008 |
Chemotherapy-induced cognitive dysfunction: a clearer picture.
Chemotherapy-associated cognitive dysfunction occurs in a subset of patients treated with adjuvant chemotherapy. Recent data suggest that development of chemotherapy-related anemia predisposes patients to cognitive dysfunction. Endogenous erythropoietin (EPO) is well recognized for its central role in erythropoiesis, and recombinant human EPO (epoetin alfa) is established as a safe and effective treatment for chemotherapy-related anemia. Treatment with epoetin alfa also improved health-related quality of life in anemic cancer patients undergoing chemotherapy, and several controlled studies have documented increases in quality-of-life scores correlated with increases in hemoglobin. Erythropoietin also plays a role in neuroprotection, presumably by activation of antiapoptotic genes. Erythropoietin and its receptor are expressed in neural cells of the human brain, and their expression is upregulated after hypoxic or ischemic injury. In animal models, systemic administration of epoetin alfa protects against such neural injury. Ongoing and future studies will determine whether epoetin alfa can provide neuroprotection with respect to the development of cognitive dysfunction in patients undergoing adjuvant chemotherapy treatment for breast cancer. Topics: Anemia; Animals; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cognition Disorders; Disease Models, Animal; Epoetin Alfa; Erythropoietin; Female; Hematinics; Humans; Quality of Life; Rats; Recombinant Proteins | 2003 |
Erythropoietic agents as neurotherapeutic agents: what barriers exist?
Erythropoietin is the primary physiological regulator of erythropoiesis, and it exerts its effect by binding to cell surface receptors. It has recently been shown that both erythropoietin and its receptor are found in the human cerebral cortex, and that, in vitro, the cytokine is synthesized by astrocytes and neurons, has neuroprotective activity, and is up-regulated following hypoxic stimuli. In animal models, exogenous recombinant human erythropoietin has been reported to be beneficial in treating experimental global and focal cerebral ischemia and reducing nervous system inflammation. These findings suggest that exogenous administration of erythropoietic agents (darbepoetin alfa [Aranesp], epoetin alfa [Epogen, Procrit], and epoetin beta [NeoRecormon]) may be a potential therapeutic tool for central nervous system injury. However, transport of protein therapeutics to the brain's extracellular environment via systemic blood supply generally does not occur due to the negligible permeability of the brain capillary endothelial wall. Therefore, in order to pharmacologically exploit and fully realize the therapeutic benefits of exogenous erythropoietic agents in CNS dysfunction, mechanisms of action and the potential impact of biodistribution barriers need to be elucidated. Topics: Animals; Blood-Brain Barrier; Brain; Brain Diseases; Clinical Trials as Topic; Darbepoetin alfa; Disease Models, Animal; Epoetin Alfa; Erythropoiesis; Erythropoietin; Humans; Neuroprotective Agents; Receptors, Erythropoietin; Recombinant Proteins | 2002 |
Effects of epoetin alfa on cognitive function, mood, asthenia, and quality of life in women with breast cancer undergoing adjuvant chemotherapy.
Several recently published studies describe moderate to severe cognitive dysfunction in breast cancer survivors who were treated with adjuvant chemotherapy 1-5 years before undergoing extensive neuropsychological testing. While these studies are hypothesis-generating and preliminary given their small size and retrospective nature, they consistently suggest that between approximately 15% and 25% of chemotherapy-treated breast cancer patients will have evidence of cognitive dysfunction some years after chemotherapy, compared to about 10% of breast cancer survivors who did not receive chemotherapy. Recent preclinical data strongly suggest that erythropoetin is a potent, endogenous neuroprotective agent that prevents neuronal apoptosis from a variety of insults including hypoxia, trauma, subarachnoidal hemorrhage, and encephalitis. Erythropoietin also appears to enhance learning in a mouse spatial learning maze model. We have conducted a pilot study of epoetin alfa versus placebo in early-stage breast cancer patients who received standard adjuvant anthracycline-based chemotherapy to determine the feasibility of administering standardized neurocognitive assessment tests in the oncology practice setting in order to understand whether the Executive Interview 25 test can detect the subtle cognitive impairment in verbal fluency, attention, and short-term memory observed with chemotherapy, and to assess whether epoetin alfa-treated patients have less evidence of cognitive dysfunction during and 6 months after chemotherapy compared with control-treated patients. We report here the preliminary results of this pilot clinical trial. Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Asthenia; Breast Neoplasms; Chemotherapy, Adjuvant; Cognition Disorders; Controlled Clinical Trials as Topic; Disease Models, Animal; Epoetin Alfa; Erythropoietin; Female; Humans; Mastectomy; Mice; Mood Disorders; Patient Satisfaction; Pilot Projects; Prognosis; Quality of Life; Recombinant Proteins; Severity of Illness Index; Treatment Outcome | 2002 |
3 trial(s) available for epoetin-alfa and Disease-Models--Animal
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Effects of ganglioside GM1 and erythropoietin on spinal cord injury in mice: Functional and immunohistochemical assessments.
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 | 2022 |
RAS modulation prevents progressive cognitive impairment after experimental stroke: a randomized, blinded preclinical trial.
With the aging population, the prevalence and incidence of cerebrovascular disease will continue to rise, as well as the number of individuals with vascular cognitive impairment/dementia (VCID). No specific FDA-approved treatments for VCID exist. Although clinical evidence supports that angiotensin receptor blockers (ARBs) prevent cognitive decline in older adults, whether ARBs have a similar effect on VCID after stroke is unknown. Moreover, these agents reduce BP, which is undesirable in the acute stroke period, so we believe that giving C21 in this acute phase or delaying ARB administration would enable us to achieve the neurovascular benefits without the risk of unintended and potentially dangerous, acute BP lowering.. The aim of our study was to determine the impact of candesartan (ARB) or compound-21 (an angiotensin type 2 receptor--AT2R--agonist) on long-term cognitive function post-stroke, in spontaneously hypertensive rats (SHRs). We hypothesized that AT2R stimulation, either directly with C21, or indirectly by blocking the angiotensin type 1 receptor (AT1R) with candesartan, initiated after stroke, would reduce cognitive impairment. Animals were subjected to a 60-min transient middle cerebral artery occlusion and randomly assigned to either saline/C21 monotherapy, for the full study duration (30 days), or given sequential therapy starting with saline/C21 (7 days) followed by candesartan for the remainder of the study (21 days). Outcome measures included sensorimotor/cognitive-function, amyloid-β determination, and histopathologic analyses.. Treatment with RAS modulators effectively preserved cognitive function, reduced cytotoxicity, and prevented chronic-reactive microgliosis in SHRs, post-stroke. These protective effects were apparent even when treatment was delayed up to 7 days post-stroke and were independent of blood pressure and β-amyloid accumulation.. Collectively, our findings demonstrate that RAS modulators effectively prevent cognitive impairment after stroke, even when treatment is delayed. Topics: Amyloid beta-Peptides; Animals; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Cell Hypoxia; Cells, Cultured; Cognitive Dysfunction; Disease Models, Animal; Double-Blind Method; Endothelial Cells; Epoetin Alfa; Hippocampus; Humans; Infarction, Middle Cerebral Artery; Locomotion; Male; Peptide Fragments; Rats; Rats, Inbred SHR; Renin-Angiotensin System; Sensory Gating; Sulfonamides; Tetrazoles; Thiophenes | 2018 |
Effects of epoetin alfa on cognitive function, mood, asthenia, and quality of life in women with breast cancer undergoing adjuvant chemotherapy.
Several recently published studies describe moderate to severe cognitive dysfunction in breast cancer survivors who were treated with adjuvant chemotherapy 1-5 years before undergoing extensive neuropsychological testing. While these studies are hypothesis-generating and preliminary given their small size and retrospective nature, they consistently suggest that between approximately 15% and 25% of chemotherapy-treated breast cancer patients will have evidence of cognitive dysfunction some years after chemotherapy, compared to about 10% of breast cancer survivors who did not receive chemotherapy. Recent preclinical data strongly suggest that erythropoetin is a potent, endogenous neuroprotective agent that prevents neuronal apoptosis from a variety of insults including hypoxia, trauma, subarachnoidal hemorrhage, and encephalitis. Erythropoietin also appears to enhance learning in a mouse spatial learning maze model. We have conducted a pilot study of epoetin alfa versus placebo in early-stage breast cancer patients who received standard adjuvant anthracycline-based chemotherapy to determine the feasibility of administering standardized neurocognitive assessment tests in the oncology practice setting in order to understand whether the Executive Interview 25 test can detect the subtle cognitive impairment in verbal fluency, attention, and short-term memory observed with chemotherapy, and to assess whether epoetin alfa-treated patients have less evidence of cognitive dysfunction during and 6 months after chemotherapy compared with control-treated patients. We report here the preliminary results of this pilot clinical trial. Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Asthenia; Breast Neoplasms; Chemotherapy, Adjuvant; Cognition Disorders; Controlled Clinical Trials as Topic; Disease Models, Animal; Epoetin Alfa; Erythropoietin; Female; Humans; Mastectomy; Mice; Mood Disorders; Patient Satisfaction; Pilot Projects; Prognosis; Quality of Life; Recombinant Proteins; Severity of Illness Index; Treatment Outcome | 2002 |
35 other study(ies) available for epoetin-alfa and Disease-Models--Animal
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Therapeutic Effect of Erythropoietin on Alzheimer's Disease by Activating the Serotonin Pathway.
Alzheimer’s disease (AD) is a neurodegenerative disease characterized by memory impairment in patients. Erythropoietin (EPO) has been reported to stimulate neurogenesis. This study was conducted to determine the regenerative effects of EPO in an AD model and to assess its underlying mechanism. Recombinant human EPO was intraperitoneally administered to AD mice induced by intracerebroventricular Aβ oligomer injection. Behavioral assessments with novel object recognition test and passive avoidance task showed improvement in memory function of the EPO-treated AD mice compared to that of the saline-treated AD mice (p < 0.0001). An in vivo protein assay for the hippocampus and cortex tissue indicated that EPO treatment modulated neurotransmitters, including dopamine, serotonin, and adrenaline. EPO treatment also restored the activity of serotonin receptors, including 5-HT4R, 5-HT7R, and 5-HT1aR (p < 0.01), at mRNA levels. Furthermore, EPO seemed to exert an anti-inflammatory influence by downregulating TLR4 at mRNA and protein levels (p < 0.05). Finally, an immunohistochemical assay revealed increments of Nestin(+) and NeuN(+) neuronal cells in the CA3 region in the EPO-treated AD mice compared to those in the saline-treated AD mice. The conclusion is that EPO administration might be therapeutic for AD by activating the serotonergic pathway, anti-inflammatory action, and neurogenic characteristics. Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Disease Models, Animal; Epoetin Alfa; Erythropoietin; Hippocampus; Humans; Mice; Neurodegenerative Diseases; Recombinant Proteins; RNA, Messenger; Serotonin | 2022 |
Pharmacological Attenuation of Electrical Effects in a Model of Compression Neuropathy.
Peripheral nerve compression and entrapment can be debilitating. Using a validated animal model of peripheral nerve compression, we examined the utility of 2 drugs approved for other uses in humans, 4-aminopyridine (4-AP) and erythropoietin (EPO), as treatments for surgically induced ischemia and as adjuvants to surgical decompression.. Peripheral nerve compression was induced in wild-type mice by placing an inert silicone sleeve around the sciatic nerve. Decompression surgery was performed at 6 weeks with mice receiving 4-AP, EPO, or saline solution either during and after compression or only after decompression. A nerve conduction study and morphometric analyses were performed to compare the extent of the injury and the efficacy of the therapies, and the findings were subjected to statistical analysis.. During peripheral nerve compression, there was a progressive decline in nerve conduction velocity compared with that in sham-treatment animals, in which nerve conduction velocity remained normal (∼55 m/s). Mice treated with 4-AP or EPO during the compression phase had significantly smaller declines in nerve conduction velocity and increased plateau nerve conduction velocities compared with untreated controls (animals that received saline solution). Histomorphometric analyses of newly decompressed nerves (i.e., nerves that underwent decompression on the day that the mouse was sacrificed) revealed that both treated groups had significantly greater proportions of large (>5-µm) axons than the untreated controls. Following surgical decompression, all animals recovered to a normal baseline nerve conduction velocity by day 15; however, treatment significantly accelerated improvement (in both the 4-AP and the EPO group), even when it was only started after decompression. Histomorphometric analyses at 7 and 15 days following surgical decompression revealed significantly increased myelin thickness and significantly greater proportions of large axons among the treated animals.. Both the 4-AP and the EPO-treated group demonstrated improvements in tissue architectural and electrodiagnostic measurements, both during and after peripheral nerve compression, compared with untreated mice.. Peripheral nerve decompression is one of the most commonly performed procedures in orthopaedic surgery. We believe that there is reason for some optimism about the translation of our findings to the clinical setting. Our findings in this murine model suggest that 4-AP and EPO may lessen the effects of nerve entrapment and that the use of these agents after decompression may speed and perhaps otherwise optimize recovery after surgery. Topics: 4-Aminopyridine; Animals; Decompression, Surgical; Disease Models, Animal; Epoetin Alfa; Hematinics; Male; Mice; Mice, Inbred C57BL; Nerve Compression Syndromes; Neural Conduction; Potassium Channel Blockers; Sciatic Neuropathy | 2019 |
Erythropoietin inhibits SGK1-dependent TH17 induction and TH17-dependent kidney disease.
IL-17-producing CD4+ cells (TH17) are pathogenically linked to autoimmunity including to autoimmune kidney disease. Erythropoietin's (EPO) newly recognized immunoregulatory functions and its predominant intra-renal source suggested that EPO physiologically regulates TH17 differentiation, thereby serving as a barrier to the development of autoimmune kidney disease. Using in vitro studies of human and murine cells and in vivo models, we show that EPO ligation of its receptor (EPO-R) on CD4+ T cells directly inhibits TH17 generation and promotes trans-differentiation of TH17 into IL-17-FOXP3+CD4+ T cells. Mechanistically, EPO/EPO-R ligation abrogates upregulation of SGK1 gene expression and blocks p38 activity to prevent SGK1 phosphorylation, thereby inhibiting RORC-mediated transcription of IL-17 and IL-23 receptor genes. In a murine model of TH17-dependent aristolochic acid (ArA)-induced, interstitial kidney disease associated with reduced renal EPO production, we demonstrate that transgenic EPO overexpression or recombinant EPO (rEPO) administration limits TH17 formation and clinical/histological disease expression. EPO/EPO-R ligations on CD4+ T cells abrogate, while absence of T cell-expressed EPO-R augments, TH17 induction and clinical/histological expression of pristane-induced glomerulonephritis (associated with decreased intrarenal EPO). rEPO prevents spontaneous glomerulonephritis and TH17 generation in MRL-lpr mice. Together, our findings indicate that EPO physiologically and therapeutically modulate TH17 cells to limit expression of TH17-associated autoimmune kidney disease. Topics: Animals; Aristolochic Acids; Cells, Cultured; Disease Models, Animal; Epoetin Alfa; Erythropoietin; Female; Humans; Immediate-Early Proteins; Interleukin-17; Lupus Nephritis; Male; Mice; Mice, Inbred MRL lpr; Mice, Transgenic; Nephritis, Interstitial; Phosphorylation; Primary Cell Culture; Protein Serine-Threonine Kinases; Receptors, Erythropoietin; Receptors, Interleukin; Severity of Illness Index; T-Lymphocytes, Regulatory; Th17 Cells | 2019 |
Erythropoietin Improves Cardiovascular Function in Adult Rats After Acute Hemorrhage.
Erythropoietin (EPO) has been linked to cardioprotective effects. However, its effects during the aging process are little known. We investigated the effect of EPO administration on hemodynamic parameters, cardiac function, oxidative damage, and erythropoietin receptor (EPOR) expression pattern in the hypovolemic state. EPO was administered (1000 IU/kg/3 days) and then acute hemorrhage (20% blood loss) was induced in young and adult rats. There was no difference in plasmatic EPO in either age group. The hemodynamic basal condition was similar, without alterations in renal function and hematocrit, in both age groups. After bleeding, both EPO-treated age groups had increased blood pressure at the end of the experimental protocol, being greater in adult animals. EPO attenuated the tachycardic effect. Ejection fraction and fractional shortening were higher in adult EPO-treated rats subjected to hemorrhage. In the left ventricle, young and adult EPO-treated rats subjected to bleeding showed an increased EPOR expression. A different EPOR expression pattern was observed in the adult right atrial tissue, compared with young animals. EPO treatment decreased oxidative damage to lipids in both age groups. EPO treatment before acute hemorrhage improves cardiovascular function during the aging process, which is mediated by different EPOR pattern expression in the heart tissue. Topics: Age Factors; Animals; Cardiovascular System; Disease Models, Animal; Epoetin Alfa; Hematinics; Hemodynamics; Hemorrhage; Lipid Peroxidation; Male; Myocardium; Oxidative Stress; Rats, Sprague-Dawley; Receptors, Erythropoietin; Ventricular Function, Left | 2019 |
Anti-Inflammatory Effect of Erythropoietin in the TNBS-induced Colitis.
Erythropoietin is a potent stimulator of erythroid progenitor cells, which is able to inhibit NF-kB activation, due to its pleiotropic properties, thus promoting an anti-inflammatory effect. As inflammatory bowel disease is a chronic disease with reduced quality of life, and the current pharmacotherapy only induces or maintains the patient in remission, there is a crucial need of new pharmacological approaches. The main objective of this study was to evaluate the effect of erythropoietin in the TNBS-induced colitis model in mice with a normal intestinal flora. Mice with TNBS-induced colitis were treated with a daily dose of erythropoietin at 500 IU/kg bw/day and 1000 IU/Kg bw/day IP during 4 days. As to clinical symptoms/signs, erythropoietin attenuated the decreased body-weight and reduced diarrhoea and oedema of the anus registered in the non-treated mice group in a dose-dependent manner. The anti-inflammatory properties of erythropoietin in the TNBS-induced colitis were confirmed by suppression of pro-inflammatory mediators, such as TNF-α, IL-1β and MPO, as well as a significant increase in the anti-inflammatory cytokine, IL-10, was promoted. These treated mice also presented a reduction in haemoglobin faecal and ALP, suggesting a beneficial effect of erythropoietin in the haemorrhagic focus and destruction of the enterocyte associated with the colon injury induced by TNBS, respectively. The histopathological score was reduced after treatment with erythropoietin, decreasing the severity and extension of the colitis. Furthermore, renal and hepatic biomarkers, as well as haematocrit concentration, remained stabilized after treatment. In conclusion, erythropoietin reduces the inflammatory response associated with TNBS-induced colitis in mice. Topics: Animals; Anti-Inflammatory Agents; Biomarkers; Colitis; Colon; Cytokines; Disease Models, Animal; Dose-Response Relationship, Drug; Epoetin Alfa; Inflammation Mediators; Male; Mice; Peroxidase; Severity of Illness Index; Time Factors; Trinitrobenzenesulfonic Acid | 2017 |
Renoprotective effect of erythropoietin in zebrafish after administration of gentamicin: an immunohistochemical study for β-catenin and c-kit expression.
Gentamicin is an aminoglycoside antibiotic widely used in the treatment of infections caused by Gram-negative bacteria. The main limitation to its therapeutic effectiveness is the potential nephrotoxicity. Erythropoietin has a tissue protective effect widely demonstrated in the kidney. The aim of the present study was to evaluate the renoprotective effects of erythropoietin in a model of zebrafish (Danio rerio) after administration of gentamicin.. Sixty adult zebrafish were subdivided into three groups: group A was treated with gentamicin; group B received gentamicin and, 24 h later, epoetin alpha; group C received drug diluent only. In order to analyze the renoprotective activity of erythropoietin, the expression of c-kit and β-catenin was evaluated by immunohistochemistry.. Generally, the zebrafish renal tubule regenerates 15 days after an injury. Conversely, 7 days after gentamicin administration, animals treated with erythropoietin (group B) showed a better renal injury repair as documented by: increased expression of β-catenin, less degenerated tubules, greater number of centers of regeneration, positivity for c-kit only in immature-looking tubules and lymphohematopoietic cells.. The expression of c-kit and β-catenin suggests that erythropoietin may exert a role in regeneration reducing the extent of tubular damage from the outset after gentamicin administration. Topics: Animals; beta Catenin; Cell Proliferation; Cytoprotection; Disease Models, Animal; Epoetin Alfa; Gentamicins; Immunohistochemistry; Kidney Diseases; Kidney Tubules; Protective Agents; Regeneration; Stem Cell Factor; Time Factors; Zebrafish; Zebrafish Proteins | 2017 |
Imaging and serum biomarkers reflecting the functional efficacy of extended erythropoietin treatment in rats following infantile traumatic brain injury.
OBJECTIVE Traumatic brain injury (TBI) is a leading cause of death and severe morbidity for otherwise healthy full-term infants around the world. Currently, the primary treatment for infant TBI is supportive, as no targeted therapies exist to actively promote recovery. The developing infant brain, in particular, has a unique response to injury and the potential for repair, both of which vary with maturation. Targeted interventions and objective measures of therapeutic efficacy are needed in this special population. The authors hypothesized that MRI and serum biomarkers can be used to quantify outcomes following infantile TBI in a preclinical rat model and that the potential efficacy of the neuro-reparative agent erythropoietin (EPO) in promoting recovery can be tested using these biomarkers as surrogates for functional outcomes. METHODS With institutional approval, a controlled cortical impact (CCI) was delivered to postnatal Day (P)12 rats of both sexes (76 rats). On postinjury Day (PID)1, the 49 CCI rats designated for chronic studies were randomized to EPO (3000 U/kg/dose, CCI-EPO, 24 rats) or vehicle (CCI-veh, 25 rats) administered intraperitoneally on PID1-4, 6, and 8. Acute injury (PID3) was evaluated with an immunoassay of injured cortex and serum, and chronic injury (PID13-28) was evaluated with digitized gait analyses, MRI, and serum immunoassay. The CCI-veh and CCI-EPO rats were compared with shams (49 rats) primarily using 2-way ANOVA with Bonferroni post hoc correction. RESULTS Following CCI, there was 4.8% mortality and 55% of injured rats exhibited convulsions. Of the injured rats designated for chronic analyses, 8.1% developed leptomeningeal cyst-like lesions verified with MRI and were excluded from further study. On PID3, Western blot showed that EPO receptor expression was increased in the injured cortex (p = 0.008). These Western blots also showed elevated ipsilateral cortex calpain degradation products for αII-spectrin (αII-SDPs; p < 0.001), potassium chloride cotransporter 2 (KCC2-DPs; p = 0.037), and glial fibrillary acidic protein (GFAP-DPs; p = 0.002), as well as serum GFAP (serum GFAP-DPs; p = 0.001). In injured rats multiplex electrochemiluminescence analyses on PID3 revealed elevated serum tumor necrosis factor alpha (TNFα p = 0.01) and chemokine (CXC) ligand 1 (CXCL1). Chronically, that is, in PID13-16 CCI-veh rats, as compared with sham rats, gait deficits were demonstrated (p = 0.033) but then were reversed (p = 0.022) with EP Topics: Age Factors; Animals; Animals, Newborn; Biomarkers; Brain Injuries, Traumatic; Calpain; Cerebral Cortex; Cytokines; Diffusion Magnetic Resonance Imaging; Disease Models, Animal; Epoetin Alfa; Erythropoietin; Female; Gait Disorders, Neurologic; Gene Expression Regulation, Developmental; Glial Fibrillary Acidic Protein; Image Processing, Computer-Assisted; K Cl- Cotransporters; Male; Rats; Receptors, Erythropoietin; Statistics, Nonparametric; Symporters; Time Factors | 2016 |
HIF‑1 signaling pathway involving iNOS, COX‑2 and caspase‑9 mediates the neuroprotection provided by erythropoietin in the retina of chronic ocular hypertension rats.
This study aimed to investigate the impacts of erythropoietin (EPO) on the electroretinogram b‑wave (ERG‑b), and on the mRNA and protein expression levels of hypoxia‑inducible factor‑1α (HIF‑1α), inducible nitric oxide synthase (iNOS), cyclooxygenase‑2 (COX‑2) and caspase‑9 in chronic ocular hypertension rats. Episcleral vein cauterization (EVC) was used to establish the chronic ocular hypertension rat model based on the intraocular pressure (IOP) value. ERG‑b and mRNA and protein expression levels of HIF‑1α, iNOS, COX‑2 and caspase‑9 in normal, EVC‑treated and EVC combined with EPO (EVC+EPO)‑treated rats were measured by electroretinography, RT‑PCR and western blotting, respectively. Moreover, the correlations of HIF‑1α with IOP, ERG‑b, iNOS, COX‑2 and caspase‑9 were evaluated. The mRNA and protein expression levels of HIF‑1α, iNOS, COX‑2 and caspase‑9 in EVC‑treated rats were increased significantly compared with normal rats. The peak expression levels of HIF‑1α, iNOS, COX‑2 and caspase‑9 were respectively obtained 7, 7, 7 and 14 days postoperatively. Compared with EVC‑treated rats, EPO administration weakened the mRNA and protein expression levels of HIF‑1α, iNOS, COX‑2 and caspase‑9. The mRNA expression level of HIF‑1α demonstrated a significant positive correlation with IOP and ERG‑b. HIF‑1α was positively correlated with iNOS, COX‑2 and caspase‑9 at the mRNA and protein levels. The protective effect of EPO on the retina of chronic ocular hypertension rats may be mediated by the HIF‑1 signaling pathway involving iNOS, COX‑2 and caspase‑9. Topics: Animals; Caspase 9; Chronic Disease; Cyclooxygenase 2; Disease Models, Animal; Electroretinography; Epoetin Alfa; Erythropoietin; Hypoxia-Inducible Factor 1, alpha Subunit; Intraocular Pressure; Male; Neuroprotective Agents; Nitric Oxide Synthase Type II; Ocular Hypertension; Rats; Rats, Wistar; Recombinant Proteins; Retina; RNA, Messenger; Signal Transduction | 2015 |
Combination of exercise training and erythropoietin prevents cancer-induced muscle alterations.
Cancer cachexia is a syndrome characterized by loss of skeletal muscle mass, inflammation, anorexia and anemia, contributing to patient fatigue and reduced quality of life. In addition to nutritional approaches, exercise training (EX) has been proposed as a suitable tool to manage cachexia. In the present work the effect of mild exercise training, coupled to erythropoietin (EPO) administration to prevent anemia, has been tested in tumor-bearing mice. In the C26 hosts, acute exercise does not prevent and even worsens muscle wasting. Such pattern is prevented by EPO co-administration or by the adoption of a chronic exercise protocol. EX and EPO co-treatment spares oxidative myofibers from atrophy and counteracts the oxidative to glycolytic shift, inducing PGC-1α. LLC hosts are responsive to exercise and their treatment with the EX-EPO combination prevents the loss of muscle strength and the onset of mitochondrial ultrastructural alterations, while increases muscle oxidative capacity and intracellular ATP content, likely depending on PGC-1α induction and mitophagy promotion. Consistently, muscle-specific PGC-1α overexpression prevents LLC-induced muscle atrophy and Atrogin-1 hyperexpression. Overall, the present data suggest that low intensisty exercise can be an effective tool to be included in combined therapeutic approaches against cancer cachexia, provided that anemia is coincidently treated in order to enhance the beneficial action of exercise. Topics: Anemia; Animals; Blotting, Western; Cachexia; Disease Models, Animal; Epoetin Alfa; Exercise Therapy; Female; Hematinics; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Transgenic; Microscopy, Electron, Transmission; Muscle, Skeletal; Muscular Atrophy; Neoplasms, Experimental; Physical Conditioning, Animal; Real-Time Polymerase Chain Reaction | 2015 |
Remote conditioning or erythropoietin before surgery primes kidneys to clear ischemia-reperfusion-damaged cells: a renoprotective mechanism?
Acute kidney injury is common, serious with no specific treatment. Ischemia-reperfusion is a common cause of acute kidney injury (AKI). Clinical trials suggest that preoperative erythropoietin (EPO) or remote ischemic preconditioning may have a renoprotective effect. Using a porcine model of warm ischemia-reperfusion-induced AKI (40-min bilateral cross-clamping of renal arteries, 48-h reperfusion), we examined the renoprotective efficacy of EPO (1,000 iu/kg iv.) or remote ischemic preconditioning (3 cycles, 5-min inflation/deflation to 200 mmHg of a hindlimb sphygmomanometer cuff). Ischemia-reperfusion induced significant kidney injury at 24 and 48 h (χ(2), 1 degree of freedom, >10 for 6/7 histopathological features). At 2 h, a panel of biomarkers including plasma creatinine, neutrophil gelatinase-associated lipocalin, and IL-1β, and urinary albumin:creatinine could be used to predict histopathological injury. Ischemia-reperfusion increased cell proliferation and apoptosis in the renal cortex but, for pretreated groups, the apoptotic cells were predominantly intratubular rather than interstitial. At 48-h reperfusion, plasma IL-1β and the number of subcapsular cells in G2-M arrest were reduced after preoperative EPO, but not after remote ischemic preconditioning. These data suggest an intrarenal mechanism acting within cortical cells that may underpin a renoprotective function for preoperative EPO and, to a limited extent, remote ischemic preconditioning. Despite equivocal longer-term outcomes in clinical studies investigating EPO as a renoprotective agent in AKI, optimal clinical dosing and administration have not been established. Our data suggest further clinical studies on the potential renoprotective effect of EPO and remote ischemic preconditioning are justified. Topics: Acute Kidney Injury; Animals; Creatinine; Disease Models, Animal; Epoetin Alfa; Erythropoietin; Female; Hindlimb; In Situ Nick-End Labeling; Ischemic Preconditioning; Preoperative Care; Recombinant Proteins; Reperfusion Injury; Swine | 2014 |
Hepatoprotective effects of erythropoietin on D-galactosamine/lipopolysaccharide-induced fulminant hepatic failure in mice.
Fulminant hepatic failure is a severe clinical syndrome associated with a high rate of patient mortality. Recent studies have shown that in addition to its hematopoietic effect, erythropoietin (EPO) has multiple protective effects and exhibits antiapoptotic, antioxidant and anti-inflammatory activities. The present study aimed to determine the hepatoprotective effect of EPO and to elucidate the underlying mechanisms using a D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced model of acute liver injury. Experimental groups of mice were administered with various doses of EPO (1,000, 3,000 or 10,000 U/kg, intraperitoneal) once per day for 3 days, prior to injection with D-GalN (700 mg/kg)/LPS (10 µg/kg). Mice were sacrificed 8 h after treatment with D‑GalN/LPS. Liver function and histopathology, malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH‑Px) activities and EPO receptor (EPOR) and phosphatidylinositol 3-kinase (PI3K) mRNA expression were evaluated. D-GalN/LPS administration markedly induced liver injury, as evidenced by elevated levels of serum aminotransferases, as well as histopathological changes. Compared with the D-GalN/LPS group, pretreatment with EPO significantly decreased the levels of aspartate aminotransferase, alanine aminotransferase and MDA, and increased the activities of SOD and GSH-Px. Furthermore, the protective effects of EPO were paralleled by an upregulation in the mRNA expression of EPOR and PI3K. These data suggest that EPO can ameliorate D-GalN/LPS-induced acute liver injury by reducing oxidative stress and upregulating the mRNA expression of EPOR and PI3K. Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Disease Models, Animal; Epoetin Alfa; Erythropoietin; Galactosamine; Glutathione Peroxidase; Lipopolysaccharides; Liver; Liver Failure, Acute; Malondialdehyde; Mice; Mice, Inbred BALB C; Phosphatidylinositol 3-Kinase; Protective Agents; Receptors, Erythropoietin; Recombinant Proteins; RNA, Messenger; Superoxide Dismutase | 2014 |
Identification of erythroferrone as an erythroid regulator of iron metabolism.
Recovery from blood loss requires a greatly enhanced supply of iron to support expanded erythropoiesis. After hemorrhage, suppression of the iron-regulatory hormone hepcidin allows increased iron absorption and mobilization from stores. We identified a new hormone, erythroferrone (ERFE), that mediates hepcidin suppression during stress erythropoiesis. ERFE is produced by erythroblasts in response to erythropoietin. ERFE-deficient mice fail to suppress hepcidin rapidly after hemorrhage and exhibit a delay in recovery from blood loss. ERFE expression is greatly increased in Hbb(th3/+) mice with thalassemia intermedia, where it contributes to the suppression of hepcidin and the systemic iron overload characteristic of this disease. Topics: Anemia; Animals; beta-Thalassemia; Blotting, Western; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Epoetin Alfa; Erythropoiesis; Erythropoietin; Gene Expression Profiling; Hemoglobins; Hemorrhage; Hepcidins; Hormones; Iron; Iron Overload; Liver; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Molecular Sequence Data; Real-Time Polymerase Chain Reaction; Recombinant Proteins; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger | 2014 |
Systemic treatment with erythropoietin protects the neurovascular unit in a rat model of retinal neurodegeneration.
Rats expressing a transgenic polycystic kidney disease (PKD) gene develop photoreceptor degeneration and subsequent vasoregression, as well as activation of retinal microglia and macroglia. To target the whole neuroglialvascular unit, neuro- and vasoprotective Erythropoietin (EPO) was intraperitoneally injected into four-week old male heterozygous PKD rats three times a week at a dose of 256 IU/kg body weight. For comparison EPO-like peptide, lacking unwanted side effects of EPO treatment, was given five times a week at a dose of 10 µg/kg body weight. Matched EPO treated Sprague Dawley and water-injected PKD rats were held as controls. After four weeks of treatment the animals were sacrificed and analysis of the neurovascular morphology, glial cell activity and pAkt localization was performed. The number of endothelial cells and pericytes did not change after treatment with EPO or EPO-like peptide. There was a nonsignificant reduction of migrating pericytes by 23% and 49%, respectively. Formation of acellular capillaries was significantly reduced by 49% (p<0.001) or 40% (p<0.05). EPO-treatment protected against thinning of the central retina by 10% (p<0.05), a composite of an increase of the outer nuclear layer by 12% (p<0.01) and in the outer segments of photoreceptors by 26% (p<0.001). Quantification of cell nuclei revealed no difference. Microglial activity, shown by gene expression of CD74, decreased by 67% (p<0.01) after EPO and 36% (n.s.) after EPO-like peptide treatment. In conclusion, EPO safeguards the neuroglialvascular unit in a model of retinal neurodegeneration and secondary vasoregression. This finding strengthens EPO in its protective capability for the whole neuroglialvascular unit. Topics: Animals; Disease Models, Animal; Epoetin Alfa; Erythropoietin; Male; Peptides; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Retinal Degeneration | 2014 |
[Effects of recombinant human erythropoietin on angiogenesis in chronic ischemic porcine myocardium].
To investigate the effect and mechanism of recombinant human erythropoietin (rhEPO) on angiogenesis in chronic ischemic porcine myocardium.. A 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.. Serum 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).. rhEPO 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. Topics: Animals; Disease Models, Animal; Epoetin Alfa; Erythropoietin; Extracellular Signal-Regulated MAP Kinases; Humans; Male; Myocardial Ischemia; Neovascularization, Physiologic; Proto-Oncogene Proteins c-akt; Recombinant Proteins; Swine; Swine, Miniature; Vascular Endothelial Growth Factor A | 2014 |
Long-term results of enriched environment and erythropoietin after hypobaric hypoxia in rats.
After global cerebral hypoxia, many patients are severely disabled even after intensive neurorehabilitation. Secondary mechanisms of brain injury as a result of biochemical and physiological events occur within a period of hours to months, and provide a window of opportunity for therapeutic intervention. Erythropoietin (EPO) has been shown to be neuroprotective in the brain subjected to a variety of injuries. Fifty-nine 3-month-old male Wistar rats were randomly distributed to experimental groups with respect to the housing (enriched environment - EE, standard housing - SH), to hypoxia exposure, and to EPO treatment. An acute mountain sickness model was used as a hypobaric hypoxia simulating an altitude of 8000 m. One half of the animals received erythropoietin injections, while the others were injected saline. Spatial memory was tested in a Morris water maze (MWM). The escape latency and the path length were measured. Better spatial learning in MWM was only seen in the group that received erythropoietin together with enriched environment. EPO administration itself had no influence on spatial memory. The results were very similar for both latencies and path lengths. These results support the idea that after brain injuries, the recovery can be potentiated by EPO administration combined with neurorehabilitation. Topics: Altitude Sickness; Animals; Behavior, Animal; Disease Models, Animal; Epoetin Alfa; Erythropoietin; Escape Reaction; Housing, Animal; Hypoxia, Brain; Male; Maze Learning; Memory; Neuroprotective Agents; Rats; Rats, Wistar; Reaction Time; Recombinant Proteins; Time Factors | 2013 |
Erythropoietin reduces brain injury after intracerebral hemorrhagic stroke in rats.
Erythropoietin (EPO) has been shown to be neuroprotective in various models of neuronal injury. The aim of the present study was to investigate the beneficial effect of recombinant human EPO (rhEPO) following intracerebral hemorrhage (ICH) and the underlying molecular and cellular mechanisms. ICH was induced using autologous blood injection in adult rats. rhEPO (5000 IU/kg) or vehicle was administered to rats with ICH 2 h following surgery and every 24 h for 1 or 3 days. To study the involvement of the PI3K signaling pathway in the rhEPO‑mediated effect, the PI3K inhibitor wortmannin (15 µg/kg), was intravenously administered to rats with ICH 90 min prior to rhEPO treatment. Brain edema was measured 3 days following ICH and behavioral outcomes were measured at 1, 7, 14, 21 and 28 days following ICH using the modified neurological severity score (mNSS) and the corner turn test. Proinflammatory cytokines, including tumor necrosis factor (TNF)‑α, interleukin (IL)-1β and IL-6, in the ipsilateral striatum were analyzed using an enzyme-linked immunosorbent assay 24 h following ICH. Neuronal apoptosis in the perihematomal area was determined by NeuN and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) double-staining. The results showed that rhEPO treatment reversed ICH, increased brain water content, upregulated proinflammatory cytokines, neuronal loss and apoptosis in the perihematomal area and rescued behavioral deficits in injured rats. Inhibiting the PI3K pathway with wortmannin abolished the rhEPO‑mediated neuroprotective effects. Moreover, western blot analysis showed that rhEPO induced the upregulation of Akt phosphorylation and downregulation of glycogen synthase kinase (GSK)‑3β phosphorylation, which were reversed by pretreatment with wortmannin, indicating the involvement of PI3K signaling in rhEPO-mediated anti-apoptotic and anti-inflammatory effects following ICH. In conclusion, these results suggested that rhEPO may exert its beneficial effects in ICH through the activation of the PI3K signaling pathway. Topics: Animals; Apoptosis; Behavior, Animal; Blotting, Western; Brain Injuries; Cells, Cultured; Cerebral Hemorrhage; Cytokines; Disease Models, Animal; Epoetin Alfa; Erythropoietin; Fluorescent Antibody Technique; Male; Neuroprotective Agents; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Signal Transduction; Stroke | 2013 |
Concurrent erythropoietin and hypothermia treatment improve outcomes in a term nonhuman primate model of perinatal asphyxia.
Up to 65% of untreated infants suffering from moderate to severe hypoxic-ischemic encephalopathy (HIE) are at risk of death or major disability. Therapeutic hypothermia (HT) reduces this risk to approximately 50% (number needed to treat: 7-9). Erythropoietin (Epo) is a neuroprotective treatment that is promising as an adjunctive therapy to decrease HIE-induced injury because Epo decreases apoptosis, inflammation, and oxidative injury and promotes glial cell survival and angiogenesis. We hypothesized that HT and concurrent Epo will be safe and effective, improve survival, and reduce moderate-severe cerebral palsy (CP) in a term nonhuman primate model of perinatal asphyxia.. Thirty-five Macaca nemestrina were delivered after 15-18 min of umbilical cord occlusion (UCO) and randomized to saline (n = 14), HT only (n = 9), or HT+Epo (n = 12). There were 12 unasphyxiated controls. Epo (3,500 U/kg × 1 dose followed by 3 doses of 2,500 U/kg, or Epo 1,000 U/kg/day × 4 doses) was given on days 1, 2, 3, and 7. Timed blood samples were collected to measure plasma Epo concentrations. Animals underwent MRI/MRS and diffusion tensor imaging (DTI) at <72 h of age and again at 9 months. A battery of weekly developmental assessments was performed.. UCO resulted in death or moderate-severe CP in 43% of saline-, 44% of HT-, and 0% of HT+Epo-treated animals. Compared to non-UCO control animals, UCO animals exhibit poor weight gain, behavioral impairment, poor cerebellar growth, and abnormal brain DTI. Compared to UCO saline, UCO HT+Epo improved motor and cognitive responses, cerebellar growth, and DTI measures and produced a death/disability relative risk reduction of 0.911 (95% CI -0.429 to 0.994), an absolute risk reduction of 0.395 (95% CI 0.072-0.635), and a number needed to treat of 2 (95% CI 2-14). The effects of HT+Epo on DTI included an improved mode of anisotropy, fractional anisotropy, relative anisotropy, and volume ratio as compared to UCO saline-treated infants. No adverse drug reactions were noted in animals receiving Epo, and there were no hematology, liver, or kidney laboratory effects.. HT+Epo treatment improved outcomes in nonhuman primates exposed to UCO. Adjunctive use of Epo combined with HT may improve the outcomes of term human infants with HIE, and clinical trials are warranted. Topics: Animals; Asphyxia; Brain; Disease Models, Animal; Epoetin Alfa; Erythropoietin; Humans; Hypothermia; Hypoxia-Ischemia, Brain; Infant; Macaca nemestrina; Recombinant Proteins; Treatment Outcome | 2013 |
A novel EPO receptor agonist improves glucose tolerance via glucose uptake in skeletal muscle in a mouse model of diabetes.
Patients treated with recombinant human Epo demonstrate an improvement in insulin sensitivity. We aimed to investigate whether CNTO 530, a novel Epo receptor agonist, could affect glucose tolerance and insulin sensitivity. A single administration of CNTO 530 significantly and dose-dependently reduced the area under the curve in a glucose tolerance test in diet-induced obese and diabetic mice after 14, 21, and 28 days. HOMA analysis suggested an improvement in insulin sensitivity, and this effect was confirmed by a hyperinsulinemic-euglycemic clamp. Uptake of (14)C-2-deoxy-D-glucose indicated that animals dosed with CNTO 530 transported more glucose into skeletal muscle and heart relative to control animals. In conclusion, CNTO530 has a profound effect on glucose tolerance in insulin-resistant rodents likely because of improving peripheral insulin sensitivity. This effect was observed with epoetin-α and darbepoetin-α, suggesting this is a class effect, but the effect with these compounds relative to CNTO530 was decreased in duration and magnitude. Topics: Animals; Darbepoetin alfa; Diabetes Mellitus, Experimental; Dietary Fats; Disease Models, Animal; Dose-Response Relationship, Drug; Epoetin Alfa; Erythropoietin; Glucose; Glucose Clamp Technique; Glucose Tolerance Test; Insulin Resistance; Male; Mice; Mice, Inbred C57BL; Muscle, Skeletal; Obesity; Receptors, Erythropoietin; Recombinant Fusion Proteins; Recombinant Proteins; Time Factors | 2011 |
Erythropoietin attenuates apoptosis after ischemia-reperfusion-induced renal injury in transiently hyperglycemic Wister rats.
Hyperglycemia is associated with a decreased tolerance to ischemia and an increased severity of renal ischemia reperfusion (I/R) injury. It has been suggested that erythropoietin (EPO) attenuates this effect in normoglycemic animals. This study sought to examine the effects of EPO on treatment renal I/R injury (IRI) in transiently hyperglycemic rats.. Twenty-eight male Wister rats anesthetized with isoflurane received glucose (2.5 g.kg(-1) intraperitoneally) before right nephrectomy. They were randomly assigned to four groups: sham operation (S); IRI (ISO); IRI+EPO, (600 UI kg(-1) low-dose EPO [EL]); and IRI+EPO 5000 UI kg(-1) (high-dose EPO [EH]). IRI was induced by a 25-minute period of left renal ischemia followed by reperfusion for 24 hours. Serum creatinine and glucose levels were measure at baseline (M1), immediately after the ischemic period (M2), and at 24 hours after reperfusion (M3). After sacrificing the animals, left kidney specimens were submitted for histological analysis including flow cytometry to estimate tubular necrosis and the percentages of apoptotic, dead or intact cells.. Scr in the ISO group was significantly higher at M3 than among the other groups. Percentages of early apoptotic cells in ISO group were significantly higher than the other groups. Percentages of late apoptotic cells in S and ISO groups were significantly greater than EL and EH groups. However, no significant intergroup differences were observed regarding the incidence of tubular necrosis.. Our results suggested that, although not preventing the occurrence of tubular necrosis, EPO attenuated apoptosis and glomerular functional impairment among transiently hyperglycemic rats undergoing an ischemia/reperfusion insult. Topics: Animals; Apoptosis; Blood Glucose; Creatinine; Cytoprotection; Disease Models, Animal; Epoetin Alfa; Erythropoietin; Flow Cytometry; Hyperglycemia; Kidney; Kidney Glomerulus; Kidney Tubules; Male; Necrosis; Nephrectomy; Rats; Rats, Wistar; Recombinant Proteins; Reperfusion Injury; Time Factors | 2011 |
Vascular endothelial growth factor is crucial for erythropoietin-induced improvement of cardiac function in heart failure.
We intended to delineate the mechanisms of erythropoietin (EPO)-induced cardiac vascular endothelial growth factor (VEGF) production and to establish if VEGF is crucial for EPO-induced improvement of cardiac performance.. The effects of EPO on VEGF expression were studied in cultured cardiac cells and EPO-treated hearts. The role of VEGF in EPO-induced neovascularization was studied with two distinct VEGF-neutralizing antibodies or irrelevant control IgG in an aortic sprouting assay and in rats with heart failure (HF) after myocardial infarction (MI) treated with EPO. EPO-alfa (10 IU/mL) was used in vitro and darbepoetin alfa (40 microg/kg/3 weeks, starting 3 weeks after MI) in vivo. EPO stimulated VEGF mRNA expression through the signal transducers and activators of transcription-3 (STAT-3) pathway in neonatal rat cardiomyocytes, but not in endothelial cells or fibroblasts. Similarly, the direct effects of EPO on endothelial sprouting were modest and VEGF independent. In rats with HF, EPO increased VEGF protein expression predominantly in cardiomyocytes, associated with a 37% increase in capillary density and improved cardiac performance. Administration of VEGF-neutralizing antibodies abrogated the salutary effects of EPO on cardiac microvascularization and function. VEGF neutralization attenuated EPO-induced proliferation of myocardial endothelial cells and reduced myocardial incorporation of endothelial progenitor cells (EPCs) in rats with alkaline phosphatase-labelled bone marrow cells.. VEGF is crucial for EPO-induced improvement of cardiac function in HF. EPO fosters VEGF expression predominantly in cardiomyocytes, which in turn stimulates myocardial endothelial proliferation and incorporation of EPCs. Topics: Animals; Animals, Newborn; Cardiotonic Agents; Cell Movement; Cell Proliferation; Cells, Cultured; Darbepoetin alfa; Disease Models, Animal; Endothelial Cells; Epoetin Alfa; Erythropoietin; Heart Failure; Humans; Male; Myocytes, Cardiac; Neovascularization, Physiologic; Paracrine Communication; Rats; Rats, Inbred F344; Rats, Sprague-Dawley; Recombinant Proteins; Recovery of Function; RNA, Messenger; STAT3 Transcription Factor; Stem Cell Transplantation; Stem Cells; Time Factors; Transcription, Genetic; Up-Regulation; Vascular Endothelial Growth Factor A; Ventricular Function, Left; Ventricular Remodeling | 2010 |
Erythropoietin reverses the attentional set-shifting impairment in a rodent schizophrenia disease-like model.
Executive function impairment, as classically assessed using the Wisconsin Card Sort Test or intradimensional/extradimensional tests, is a key feature of schizophrenia but remains inadequately treated by existing therapies. Recently, however, erythropoietin has been shown to improve attentional set-shifting performance in schizophrenic patients.. The present study utilized the rat intradimensional/extradimensional task to investigate the potential of erythropoietin to reverse a phencyclidine-induced extradimensional shift impairment when given alone or in combination with subchronic haloperidol treatment.. Rats were subjected to a subchronic systemic administration (7 days, b.i.d) of either saline vehicle or phencyclidine (5 mg/kg) followed by a 7-day washout period during which haloperidol was given. Subsequently, rats were trained to dig in baited bowls for a food reward and to discriminate on the basis of digging media or bowl odor. In experiment 1, rats performed a series of discriminations following acute administration of vehicle, erythropoietin, or modafinil. In a second experiment, rats receiving either haloperidol in the drinking water or just normal drinking water were run in the attentional set-shifting task after acute administration of erythropoietin (1,000 or 10,000 IU/ml i.p., selected from experiment 1).. The subchronic phencyclidine-induced extradimensional deficit was ameliorated by both erythropoietin and modafinil. When combined with subchronic haloperidol, the higher dose of erythropoietin tested was able to reverse the extradimensional shift impairment.. Overall, these findings further support the use of erythropoietin as an adjunct to antipsychotic therapy in order to address, at least part of, the cognitive dysfunction associated with schizophrenia. Topics: Animals; Antipsychotic Agents; Attention; Behavior, Animal; Benzhydryl Compounds; Discrimination, Psychological; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Therapy, Combination; Epoetin Alfa; Erythropoietin; Executive Function; Haloperidol; Male; Modafinil; Neuropsychological Tests; Phencyclidine; Rats; Recombinant Proteins; Reward; Schizophrenia; Schizophrenic Psychology | 2010 |
Failure of erythropoietin to render jeopardized ischemic myocardium amenable to incremental salvage by early reperfusion.
Erythropoietin (EPO) has been thought to be capable of potentiating protection of jeopardized myocardium by reperfusion in evolving myocardial infarction. However, diversity in study design and measurements of infarct size in studies evaluating EPO has led to inconsistent results. We sought to characterize the effect of EPO on infarct size after myocardial ischemia and reperfusion with the use of assessment of left-ventricular (LV) creatine kinase (CK) depletion and echocardiography.. Acute coronary occlusion was induced in 10-week-old C57BL6 mice by left anterior descending coronary artery ligation for 3 h followed by 72 h of reperfusion. EPO (10,000 U/kg) or an equivalent amount of saline vehicle alone was injected intraperitoneally before ligation or immediately after the onset of reperfusion. Assays of residual LV CK activity and calculation of LV CK depletion were performed on LV homogenates harvested 72 h after onset of reperfusion for measurement of infarct size, and echocardiography was performed immediately before harvest of tissue for measurement of function.. Mice administered EPO before ligation had similar infarct size (37.1+/-4.1%) and echo scores (22.9+/-0.4) compared with those in corresponding control mice administered saline (35.29+/-1.9 and 21.3+/-1.1%, respectively). Mice administered EPO after reperfusion had similar infarct size (39.1+/-4.8%) and echo scores (19.5+/-1.0) compared with those in corresponding control mice administered saline (40.3+/-4.9 and 21.5+/-1.9%, respectively).. EPO does not protect ischemic myocardium such that reperfusion after 3 h can yield additional salvage. Topics: Animals; Biomarkers; Creatine Kinase; Disease Models, Animal; Echocardiography, Doppler; Epoetin Alfa; Erythropoietin; Injections, Intraperitoneal; Male; Mice; Mice, Inbred C57BL; Myocardial Contraction; Myocardial Infarction; Myocardial Ischemia; Myocardial Reperfusion Injury; Myocardium; Recombinant Proteins; Time Factors; Ventricular Function, Left | 2009 |
Effects of erythropoietin on reducing brain damage and improving functional outcome after traumatic brain injury in mice.
This study was designed to investigate the beneficial effects of recombinant human erythropoietin (rhEPO) treatment of traumatic brain injury (TBI) in mice.. Adult male C57BL/6 mice were divided into 3 groups: 1) the saline group (TBI and saline [13 mice]); 2) EPO group (TBI and rhEPO [12]); and 3) sham group (sham and rhEPO [8]). Traumatic brain injury was induced by controlled cortical impact. Bromodeoxyuridine (100 mg/kg) was injected daily for 10 days, starting 1 day after injury, for labeling proliferating cells. Recombinant human erythropoietin was administered intraperitoneally at 6 hours and at 3 and 7 days post-TBI (5000 U/kg body weight, total dosage 15,000 U/kg). Neurological function was assessed using the Morris water maze and footfault tests. Animals were killed 35 days after injury, and brain sections were stained for immunohistochemical evaluation.. Traumatic brain injury caused tissue loss in the cortex and cell loss in the dentate gyrus (DG) as well as impairment of sensorimotor function (footfault testing) and spatial learning (Morris water maze). Traumatic brain injury alone stimulated cell proliferation and angiogenesis. Compared with saline treatment, rhEPO significantly reduced lesion volume in the cortex and cell loss in the DG after TBI and substantially improved recovery of sensorimotor function and spatial learning performance. It enhanced neurogenesis in the injured cortex and the DG.. Recombinant human erythropoietin initiated 6 hours post-TBI provided neuroprotection by decreasing lesion volume and cell loss as well as neurorestoration by enhancing neurogenesis, subsequently improving sensorimotor and spatial learning function. It is a promising neuroprotective and neurorestorative agent for TBI and warrants further investigation. Topics: Animals; Brain Injuries; Disease Models, Animal; Drug Administration Schedule; Epoetin Alfa; Erythropoietin; Hematinics; Male; Maze Learning; Mice; Mice, Inbred C57BL; Psychomotor Performance; Recombinant Proteins; Recovery of Function | 2008 |
Nonerythropoietic derivative of erythropoietin protects against tubulointerstitial injury in a unilateral ureteral obstruction model.
Erythropoietin (EPO), a member of the cytokine type I superfamily, acts to increase circulating erythrocytes primarily by preventing apoptosis of erythroid progenitors, is known to protect tissues and can raise haemoglobin (Hb) concentrations. Recently, a second receptor for EPO comprising the EPO receptor and beta-common receptor has been reported to mediate EPO-induced tissue protection. EPO modified by carbamylation (CEPO) only signals through this second receptor. Accordingly, we hypothesized that treatment with CEPO, which would not increase Hb concentrations, would protect against tubular damage and thereby inhibit tubulointerstitial injuries.. We evaluated therapeutic effects of CEPO using a rat unilateral ureteral obstruction model.. CEPO decreased tubular apoptosis and alpha-smooth muscle actin (alphaSMA) expression in the absence of polycythaemia, while the untreated obstructed kidneys exhibited increased tubular apoptosis with expanded (alphaSMA) expression. While EPO treatment similarly inhibited tubular apoptosis and alphaSMA expression, EPO treatment increased Hb concentrations and induced a wedge-shaped infarction.. We established a therapeutic approach using CEPO to protect against tubulointerstitial injury. The therapeutic value of this approach warrants further attention and preclinical studies. Topics: Actins; Animals; Apoptosis; Disease Models, Animal; Epoetin Alfa; Erythropoiesis; Erythropoietin; Hemoglobins; Infarction; Kidney; Kidney Tubules; Male; Rats; Rats, Sprague-Dawley; Receptors, Erythropoietin; Recombinant Proteins; Signal Transduction; Ureteral Obstruction | 2008 |
The relationship between erythropoietin pretreatment with blood-brain barrier and lipid peroxidation after ischemia/reperfusion in rats.
Blood-brain barrier (BBB) leakage plays a role in the pathogenesis of many pathological states of the brain including ischemia and some neurodegenerative disorders. In recent years, erythropoietin (EPO) has been shown to exert neuroprotection in many pathological conditions including ischemia in the brain. This study aimed to investigate the effects of EPO on BBB integrity, infarct size and lipid peroxidation following global brain ischemia/reperfusion in rats. Wistar male rats were divided into four groups (each group n=8); Group I; control group (sham-operated), Group II; ischemia/reperfusion group, Group III; EPO treated group (24 h before decapitation--000 U/kg r-Hu EPO i.p.), Group IV; EPO+ ischemia/reperfusion group (24 h before ischemia/reperfusion--3000 U/kg r-Hu EPO i.p.). Global brain ischemia was produced by the combination of bilateral common carotid arteries occlusion and hemorrhagic hypotension. Macroscopical and spectrophotometrical measurement of Evans Blue (EB) leakage was observed for BBB integrity. Infarct size was calculated based on 2,3,5-triphenyltetrazolium chloride (TTC) staining. Lipid peroxidation in the brain tissue was determined as the concentration of thiobarbituric acid-reactive substances (TBARS) for each group. Ischemic insult caused bilateral and regional BBB breakdown (hippocampus, cortex, corpus striatum, midbrain, brain stem and thalamus). EPO pretreatment reduced BBB disruption, infarct size and lipid peroxide levels in brain tissue with 20 min ischemia and 20 min reperfusion. These results suggest that EPO plays an important role in protecting against brain ischemia/reperfusion through inhibiting lipid peroxidation and decreasing BBB disruption. Topics: Animals; Blood-Brain Barrier; Brain Infarction; Brain Ischemia; Carotid Arteries; Carotid Stenosis; Disease Models, Animal; Drug Administration Schedule; Epoetin Alfa; Erythropoietin; Evans Blue; Lipid Peroxidation; Male; Neuroprotective Agents; Rats; Rats, Wistar; Recombinant Proteins; Reperfusion Injury; Thiobarbituric Acid Reactive Substances | 2007 |
Prevention of erythropoietin-associated hypertension.
Hypertension is the most significant complication from treatment with erythropoietin (Epo). Can Epo-induced hypertension be eliminated? We examined systemic and local effects of our genetically engineered products, Epo-binding protein (Epo-bp) and anti-Epo-bp antibodies, on randomly assigned Sprague-Dawley rats at midnight, 4 am, 8 am, noon, 4 pm, and 8 pm. Blood pressure, hematocrit, and body weight were measured immediately before and after the completion of a 4-week, twice-weekly course of Epo (50 U/kg), Epo-bp, anti-Epo-bp antibodies, or physiological saline injections. Epo treatment increased hematocrit markedly overall as compared with the saline, Epo-bp, and anti-Epo-bp antibody groups (0.616 versus 0.427, 0.439, and 0.441, respectively) and at each of the 6 test times (all P<0.0001). Epo-bp and anti-Epo-bp antibody treatment with Epo had almost no effect on the Epo-induced hematocrit increase (0.616 versus 0.580 or 0.591, respectively). Circadian blood pressures for Epo versus saline, Epo-bp, and anti-Epo-bp antibody groups were 136.2+/-2.3 versus 116.2+/-1.7, 118.4+/-2.1, and 116.6+/-2.1 mm Hg, respectively (each P<0.0001). Significantly increased blood pressure was detected at noon, 4 pm, 8 pm, and midnight in Epo treatment. When Epo was given with Epo-bp or anti-Epo-bp antibodies, blood pressure was maintained at similar levels as in saline treatment (each P<0.0001) as compared with Epo treatment alone. Overall, body, brain, and heart weights were significantly lower in Epo treatment than those of other groups. Thus, Epo-bp and anti-Epo-bp antibodies eliminate Epo-induced hypertension without affecting hematocrit and blood volume. Topics: Animals; Blood Pressure Determination; Body Weight; Circadian Rhythm; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Administration Schedule; Epoetin Alfa; Erythropoiesis; Erythropoietin; Hematocrit; Hypertension; Probability; Protein Binding; Random Allocation; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Reference Values; Risk Factors; Sensitivity and Specificity | 2007 |
Post-ischemic treatment with erythropoietin or carbamylated erythropoietin reduces infarction and improves neurological outcome in a rat model of focal cerebral ischemia.
Recombinant human erythropoietin (rhEPO; Epoetin-alpha; PROCRITtrade mark) has been shown to exert neuroprotective and restorative effects in a variety of CNS injury models. However, limited information is available regarding the dose levels required for these beneficial effects or the neuronal responses that may underlie them. Here we have investigated the dose-response to rhEPO and compared the effects of rhEPO with those of carbamylated rhEPO (CEPO) in a model of cerebral stroke in rats.. Rats subjected to embolic middle cerebral artery occlusion (MCAo) were treated with rhEPO or CEPO, starting at 6 h and repeated at 24 and 48 h, after MCAo. Cerebral infarct volumes were assessed at 28 days and neurological impairment at 7, 14, 21 and 28 days, post-MCAo.. rhEPO at dose levels of 500, 1150 or 5000 IU kg(-1) or CEPO at a dose level of 50 microg kg(-1) significantly reduced cortical infarct volume and reduced neurologic impairment. All doses of rhEPO, but not CEPO, produced a transient increase in haematocrit, while rhEPO and CEPO substantially reduced the number of apoptotic cells and activated microglia in the ischemic boundary region.. These data indicate that rhEPO and CEPO have anti-inflammatory and anti-apoptotic effects, even with administration at 6 h following embolic MCAo in rats. Taken together, these actions of rhEPO and CEPO are likely to contribute to their reduction of neurologic impairment following cerebral ischemia. Topics: Animals; Apoptosis; Blood-Brain Barrier; Brain Ischemia; Disease Models, Animal; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Epoetin Alfa; Erythropoietin; Hematinics; Hematocrit; Infarction, Middle Cerebral Artery; Male; Microglia; Neuroprotective Agents; Rats; Rats, Wistar; Recombinant Proteins; Stroke | 2007 |
Novel evidence suggesting an anti-oxidant property for erythropoietin on vancomycin-induced nephrotoxicity in a rat model.
1. The aim of the present study was to investigate the role of oxidative stress in renal injury and to determine whether erythropoietin (EPO) acts as an anti-oxidant in vancomycin (VCM)-induced renal impairment. 2. Twenty-four rats were divided into three groups as follows: (i) control (Group 1); (ii) VCM treated (Group 2); and (iii) VCM + EPO treated (Group 3). Vancomycin (200 mg/kg, i.p.) was administered to Groups 2 and 3 for 7 days. Erythropoietin (150 IU/kg, i.p.) treatment was started 24 h before VCM and lasted for 7 days. On Day 8, renal tissues were excised and blood samples were collected. Serum creatinine and blood urea nitrogen were measured, along with renal malondialdehyde (MDA) levels, superoxide dismutase (SOD) and catalase (CAT) activity and tissue VCM levels. The kidneys were examined for any histopathological changes. 3. Renal MDA levels were found to be increased, whereas SOD and CAT activity was decreased, in the VCM-treated group compared with the control group. There was a marked decrease in MDA levels and an increase in SOD activity, but not CAT activity, after VCM + EPO treatment. Marked histopathological alterations, including interstitial oedema, tubular dilatation, tubular epithelial cell desquamation and vacuolization, were observed in VCM-treated rats. Histopathological changes were significantly improved after EPO administration. 4. In conclusion, the present data suggest that oxidative stress plays an important role in VCM-induced nephrotoxicity. Erythropoietin seems to act as an anti-oxidant, diminishing the toxic oxidative effects of VCM on renal tissues. Topics: Animals; Anti-Bacterial Agents; Antioxidants; Blood Urea Nitrogen; Catalase; Creatinine; Disease Models, Animal; Epoetin Alfa; Erythropoietin; Kidney; Kidney Diseases; Male; Malondialdehyde; Oxidative Stress; Rats; Rats, Wistar; Recombinant Proteins; Superoxide Dismutase; Vancomycin | 2007 |
Administration of erythropoietin fails to improve long-term healing or cardiac function after myocardial infarction in the rat.
Erythropoietin (epo), initially recognized and used clinically to increase erythropoiesis, has been shown to have beneficial effects on various other tissues in the setting of hypoxia and ischemia. Epo has been shown to reduce apoptosis after myocardial infarction, but few studies have evaluated the long-term effects of epo treatment on left ventricular (LV) remodeling, cardiac function, and blood flow after healing of a permanent coronary artery occlusion. The aim of this study was to assess the effects of epo treatment on the healed heart 6 weeks after myocardial infarction. Anesthetized rats underwent coronary artery occlusion and were treated with erythropoietin (5000 units/kg/day, n=21) or saline (n=20) the day before surgery, the day of, then for 5 days. At 6 weeks LV ventriculography to assess LV volumes and ejection fractions and histologic assessment of infarct size and LV cavity and wall dimensions were performed. Overall epo had no effect on LV remodeling or cardiac function. There were no significant differences in infarct morphology, infarct size (44+/-3% of the LV circumference versus 39+/-3%), LV cavity area, scar thickness, LV systolic volume, or ejection fraction (44+/-3% versus 39+/-3%) between the epo and saline groups, respectively. However, for any given size of myocardial infarct, LV ejection fraction was significantly higher in erythropoietin hearts and LV systolic volumes lower. Thus, in our model, treatment with epo had no long-term beneficial effect on LV remodeling after myocardial infarction but may have exerted some positive effect on LV function. Topics: Animals; Coronary Circulation; Disease Models, Animal; Epoetin Alfa; Erythropoietin; Female; Myocardial Infarction; Myocardium; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Time Factors; Treatment Failure; Ventricular Function, Left; Ventricular Remodeling | 2005 |
Erythropoietin induced tumour mass reduction in murine lymphoproliferative models.
Topics: Animals; Cell Line, Tumor; Disease Models, Animal; Epoetin Alfa; Erythropoietin; Female; Leukemia, B-Cell; Lymphoma, B-Cell; Lymphoproliferative Disorders; Mice; Mice, Inbred BALB C; Plasmacytoma; Recombinant Proteins | 2005 |
Recombinant human erythropoietin attenuates weight loss in a murine cancer cachexia model.
Within hypoxic tumor regions anaerobic dissimilation of glucose is the sole source of energy generation. It yields only 5% of the ATP that is normally gained by means of oxidative glucose catabolism. The increased need for glucose may aggravate cancer cachexia. We investigated the impact of recombinant human erythropoietin (RhEPO) and increased inspiratory oxygen concentrations on weight loss in tumor-bearing mice.. Fragments of the murine C26-B adenocarcinoma were implanted in 60 BALB/c-mice. The mice were divided into four groups and assigned to: (A) no treatment; (B) RhEPO- administration (25 IU daily from day 1-11, three times per week from day 12); (C) RhEPO and 25% oxygen; and (D) RhEPO and 35% oxygen. Three control groups of four healthy mice each received the same treatment as groups A, B, and D, respectively. Hematocrit and hemoglobin levels, tumor volume, and body weight were monitored. At day 17 the experiment was terminated and the serum lactate concentration was measured. The tumors were excised and weighed and, for each mouse, the percentage weight loss was calculated. The impact of tumor weight and the treatments on lactate concentration and weight loss was evaluated.. Significant positive correlations were found between tumor weight and lactate concentration and between tumor weight and percentage weight loss. In the mice with the largest tumors, RhEPO displayed a significant weight loss-reducing effect, and a significant negative correlation was found between hemoglobin concentration and weight loss. An oxygen-rich environment did not appear to influence weight loss.. Anaerobic glycolysis in a growing C26-B tumor is related to weight loss. RhEPO administration results in a reduction of the percentage weight loss; this effect is probably mediated by an increased hemoglobin concentration. Topics: Adenocarcinoma; Animals; Cachexia; Disease Models, Animal; Epoetin Alfa; Erythropoietin; Glycolysis; Hematocrit; Hemoglobins; Inhalation; Mice; Mice, Inbred BALB C; Oxygen; Recombinant Proteins; Weight Loss | 2004 |
Modulation of the course and outcome of blood-stage malaria by erythropoietin-induced reticulocytosis.
Severe anemia is a major life-threatening complication of malaria. The roles of erythropoietin (Epo) and erythropoiesis during blood-stage malaria were investigated. By treating Plasmodium chabaudi AS-infected C57BL/6 (B6) mice, which are resistant to malaria, with polyclonal anti-human Epo neutralizing antibody, we demonstrated that Epo-induced reticulocytosis was important for alleviating malarial anemia and for host survival. By inducing erythropoiesis in A/J mice, which are susceptible to malaria, and in B6 mice at various periods during infection, by use of exogenous recombinant murine Epo, untimely onset of reticulocytosis was shown to augment multiplication of parasites and result in lethal infection. However, timely inducement of reticulocytosis with Epo treatment alleviated malarial anemia and increased survival. Our data reveal the important role of Epo-induced reticulocytosis in modulating the course and outcome of blood-stage malaria. However, the mechanisms underlying the increased mortality associated with untimely treatment with Epo and the increased protection associated with timely treatment with Epo remain to be investigated. Topics: Animals; Disease Models, Animal; Disease Susceptibility; Epoetin Alfa; Erythropoietin; Malaria; Male; Mice; Mice, Inbred A; Mice, Inbred C57BL; Plasmodium chabaudi; Recombinant Proteins; Reticulocytosis; Treatment Outcome | 2004 |
Erythropoietin and radiotherapy: a dangerous combination?
Topics: Anemia; Cell Hypoxia; Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Disease Models, Animal; Dose Fractionation, Radiation; Epoetin Alfa; Erythropoietin; Female; Head and Neck Neoplasms; Hematinics; Hemoglobins; Humans; Male; Meta-Analysis as Topic; Neoplasm Recurrence, Local; Neoplasms; Pelvic Neoplasms; Placebos; Prognosis; Radiotherapy Dosage; Recombinant Proteins; Retrospective Studies; Risk; Risk Factors; Time Factors; Treatment Outcome; Uterine Cervical Neoplasms | 2004 |
[Report of the National Oncology Research and Developement Consortium, 2003].
Consorcial projects focused on 5 cancer types, breast-, colorectal-, head and neck- and pediatric cancers, and malignant melanoma. Breast cancer studies revealed unique splicing mechanisms concerning BRCA1. In sporadic breast cancers the involvement of DNA-repair genes was proved to be dependent on the histological type. Bone-metastatic tumors have been characterized by decreased NM23 and increased c-met and p53 expressions. C-erbB2 genotype of the primary tumor was not maintained frequently in bone metastases. Application of DNA-microarray and quantitative PCR technologies improved the prediction of therapeutic sensitivity of breast cancers. Colorectal cancer studies revealed regional inhomogenities (clusters) in various geographical regions of Hungary, which were distinct in the case of colonic and rectal cancers. To increase the sensitivity of fecal blood test of colorectal cancer screening, a new double-antibody test was developed and tested in a large cohort of patients. Genetic analysis revealed that hypermethylation is a significant factor in microsatellite instability which, and plays a role in silencing of APC and E-cadherin genes as well. The Hungarian pattern of TS polymorphism was also determined and was correlated not only with the efficacy of 5-FU treatment but with the progression of the disease as well. Population-based studies have been carried out in head and neck cancer patients (HNC) and smokers as well to reveal the genetic background of increasing tumor incidence. These studies revealed polymorphism in XRCC1/3 methylation enzyme gene which has preventive role. Other studies found frequent local immunosuppression in HNC patients. Studies indicated that the success of irradiation in this cancer type is dependent on the anti-vascular effects. Pediatric cancer studies determined the parameters of neuroblastoma screening based on VMA measurements. New splice variants of the WT1 gene involved in the monitoring of MRD of ALL patients was also described this year. We also obtained positive experimental data for the retinoic acid therapy of ALL. Melanoma studies extensively used DNA-microarray technology which identified 4 melanoma-specific and 2 melanoma progression-specific genes. In experimental human melanoma xenograft models we have identified 3 anti-metastatic agents: low molecular weight heparin, 2-methoxyestradiol and erythropoietin-alpha, where the later was characterized by specific effects on tumor vasculature. Topics: 2-Methoxyestradiol; Adult; Animals; Antineoplastic Agents; Biomarkers, Tumor; Biomedical Research; Bone Neoplasms; Breast Neoplasms; Child; Colorectal Neoplasms; Disease Models, Animal; Disease Progression; DNA Methylation; Epoetin Alfa; Erythropoietin; Estradiol; Female; Gene Expression Regulation, Neoplastic; Gene Silencing; Genetic Markers; Head and Neck Neoplasms; Heparin, Low-Molecular-Weight; Humans; Hungary; Incidence; Male; Melanoma; Microsatellite Repeats; Oligonucleotide Array Sequence Analysis; Polymerase Chain Reaction; Polymorphism, Genetic; Predictive Value of Tests; Recombinant Proteins; Transplantation, Heterologous | 2004 |
Epoetin alfa: future directions and future research.
Topics: Anemia; Animals; Cell Hypoxia; Clinical Trials as Topic; Disease Models, Animal; Epoetin Alfa; Erythropoietin; Hematinics; Humans; Neoplasms; Quality of Life; Recombinant Proteins | 2004 |