Recombinant Human Epo Research Articles

Cost Minimized Immunoaffinity Purification of EPO and Its Analogs in Doping Control-A Step-by-Step Protocol for Human Urine and Blood.

A cost minimized immunoaffinity protocol was developed, which allows the direct purification of ERAs (urinary and recombinant human EPO, Darbepoetin, EPO-Fc, CERA) from human urine. The method applies magnetic beads and needs no covalent immobilization of the capture antibody. It requires only 10 mL of urine, 1 μg of anti-EPO antibody, and 25 μL of bead slurry. The beads are coated with the capture antibody in advance and can be stored in the refrigerator for months without any loss of functionality. The protocol was fully validated in combination with SAR-PAGE and Western blotting using the biotinylated clone AE7A5 anti-EPO antibody. It is compliant with the criteria of TD2024EPO of the World Anti-Doping Agency (WADA) for the gel electrophoretic detection of ERAs. For each ERA, the achieved limit of detection (LOD) is at least one tenth of the minimum required performance limit (MRPL) of WADA, that is, 0.1 IU/L, 0.1 pg/mL, 0.5 pg/mL, and 0.5 pg/mL for rEPO, Darbepoetin, EPO-Fc, and CERA, respectively. After slight modification, the protocol is also applicable to serum and plasma and also fulfils the corresponding MRPLs of WADA for these matrices. Compared to commercial immunoaffinity purification kits for EPO, the material costs are significantly lower but with identical results.

The Use of Erythropoietin in Cancer Treatment and Its Correlation with Ovarian Cancer

Erythropoietin is produced by the kidneys, which can stimulate the production of red blood cells, and has a better therapeutic and prognostic role in cancer anemia. Ovarian cancer, which originates from ovarian tissue, is one of the malignant tumors of the female reproductive system, with high lethality and not easy to detect. It has been proved that EPO in correlates with the growth of tumor cells, and its receptor EPOR and recombinant human EPO (rhEPO) are expressed in cancer cells. EPO can treat EPO tumors by restoring endothelial erythrocytes and promoting angiogenesis, while rhEPO mainly has a better ameliorative effect on cancer anemia induced by radiotherapy. However, it remains controversial and contradictory whether EPO has a concomitant promoting effect on tumor cells while relieving ischemia. In this article, we will introduce the sources of EPO and EPOR in vivo, analyze the pathways that promote erythropoiesis, and analyze their effects on tumor cells. It will also confirm the correlation between the two by analyzing the EPO content in ovarian cells. The intervention effect of rhEPO analogs on cancer is also briefly described. Since aberrant activation of the JAK/STAT signaling pathway may exist in ovarian cancer patients, in-depth study of such targets may become a new research direction for the treatment of ovarian cancer.

Tracking the ancestral functions of erythropoietin: neuroprotection & mitochondria

It has long been thought that erythropoietin (Epo) is exclusively involved in erythropoiesis; now, it is known that EPO in mammal's brain plays key roles in the development, maintenance, protection, and repair of the nervous system. Also, EPO in mammals contributes to the efficient use of oxygen through the regulation of mitochondrial bioenergetic. Remarkably, a similar neuroprotective impact of recombinant human EPO (rhEPO) has been found in the brain of grasshoppers, raising questions about the evolutive origin of the EPO and its generic molecular function. The objective of this study is to show that the neuroprotective effect of rhEPO in insects involves the regulation of mitochondrial functions. The experiments were performed in crickets (Acheta domesticus). These insects were exposed under normoxia and hypoxia (5 days; 6% O2) conditions. Before experimentation, the animals were treated with EPO (30 IU/ml ‐ intra‐lymphatic injection) or PBS, as a control. The brains of the crickets were removed, and then we determined the mitochondrial respiration and production of mitochondrial ROS using our system oxygraphy ‐ 2K (ORORBOROS). Our results show that compares to normoxia; hypoxia significantly reduces mitochondrial respiration of complexes 1 and 1&2. On the other hand, the treatment of EPO in hypoxia, despite significantly increasing these parameters, does not recover the levels of mitochondrial respiration under normoxic conditions. In addition, the activity of complex IV (an indicator of the number of mitochondria) does not vary significantly between any of the treatments. Furthermore, we observed that while hypoxia did not significantly affect H2O2 production, the treatment with EPO increased ROS production under normoxic but not hypoxic conditions. Our data suggest that rhEPO regulates in some way the mitochondrial respiration and ROS production in the brain of crickets. Considering that insects appeared during a geological period (Cambrian explosion) in which the atmospheric O2 was increasing, which could cause great oxidative stress due to the change in the metabolism of these animals, this molecule would have appeared as a regulator of mitochondrial functions.

A Reference Standard for Analytical Testing of Erythropoietin

PurposeErythropoietin (EPO) is a 165 amino acid protein that promotes the proliferation of erythrocytic progenitors. A decrease in endogenous EPO production causes anemia that can be treated with recombinant Human EPO (rHuEPO).ObjectiveTo ensure the safety and efficacy of the rHuEPO, manufacturers must use analytical methods to demonstrate similarity across batches and between different products. To do this they need reference standards to validate their equipment and methods.MethodWe used peptide mapping, size-exclusion chromatography, glycoprofiling, and isoelectric focusing to analyze a rHuEPO reference standard.ResultsCharacterization demonstrates that our rHuEPO reference standard meets the criteria for quality.ConclusionThe rHuEPO reference standard is fit for purpose as a tool for validating system suitability and methods.

Defining the specificity of recombinant human erythropoietin confirmation in equine samples by liquid chromatography‐tandem mass spectrometry

The proteotypic human EPO peptides YLLEAK (T4), SLTTLLR (T11), TITADTFR (T14), and VYSNFLR (T17) are often used to confirm the presence of recombinant human EPO (rhEPO) in equine samples. Each of these peptides contains one or more isomeric leucine or isoleucine amino acids, raising the possibility that a simple leucine/isoleucine substitution could lead to a false identification when compared with a rhEPO reference standard. To examine this possibility variants of these four peptides were analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). These studies indicate that confirmation of rhEPO in equine samples by immuno-affinity capture and LC-MS/MS analysis is true and accurate. It was also found that chromatography played a greater role in determining LC-MS/MS specificity than tandem mass spectrometry and that, in the case of more hydrophilic peptides, the accuracy of peptide identification could be enhanced by the inclusion of 13 C and 15 N labelled peptide internal standards.

Role of hepcidin as a biomarker for iron status and its effect on anemia management in patients with chronic kidney disease (stage II-Iv) after HCV treatment

Abstract Background Anemia is a severe complication of chronic kidney disease (CKD) that is seen in more than 80% of patients with impaired renal function. Although there are many mechanisms involved in the pathogenesis of anemia of renal disease, the primary cause is the inadequate production of erythropoietin by the damaged kidneys. Aim of the work to assess hepcidin level in non dialysis patients (CKD stage 4 &5) treated from Hepatitis C virus and its relation to iron parameters. Patients and Methods This study was conducted on 20 CKD patients (stage 4 and 5) treated from hepatitis C virus. All candidates included in this study subjected to careful history taking, full clinical examination and investigations (including complete blood count, renal chemistry, HCVAb, serum iron, total iron binding capacity, TSAT%, ferritin and hsCRP. Serum hepcidin was analyzed by ELISA technique. Results Serum hepcidin was 26.35±7.26; 40% in stage III, 37.8% in stage IV and 22.2% in stage V. There was statistically significant difference between GFR stages according to Hb., Drug intake ACE inhibitor/ARB, Plt., Creatinine, BUN, Iron, TIBC, Ferritin, T SAT%, CRP and Serum Hepcidin. We showed significant correlations between serum hepcidin and TIC, Iron, TIBC, Ferritin and TSAT%. Conclusion Median hepcidin value is elevated in nondialysis CKD patients due to increased inflammation and decreased clearance of hepcidin. Furthermore, iron status modifies serum hepcidin level and its association with Hb. Increased hepcidin level leads to iron-restricted erythropoiesis and recombinant human EPO (rhEPO) resistance by inhibiting iron absorption from gut and iron recycling from macrophages. Hence, elevated hepcidin can predict need for parenteral iron to overcome hepcidin-mediated iron-restricted erythropoiesis and need for relatively higher rhEPO doses to suppress hepcidin.

A Gain-of-Function Mutation in EPO Gene Causes Familial Erythrocytosis

Mutations in the erythropoietin-receptor gene (EPOR) are well known causes of inherited forms of primary erythrocytosis that is characterized by low serum erythropoietin (Epo) levels. Secondary erythrocytosis with elevated Epo serum levels is mainly caused by mutations in genes involved in oxygen sensing pathway. Epo is the primary regulator of erythropoiesis, but mutations in the EPO gene have so far not been described as a cause or erythrocytosis. Here we studied a Norwegian family with autosomal dominant erythrocytosis and elevated Epo serum levels.We performed genome-wide linkage analysis using SNP arrays on 16 informative family members including 10 affected individuals and identified a co-segregating region on chromosome 7q22.1 with a LOD score of 3.3. Targeted sequencing of all 215 genes within the co-segregating region revealed only a heterozygous single base deletion in exon 2 of EPO as the sole candidate gene mutation. ThisΔG deletion creates a frame-shift that truncates the Epo signal peptide and generates a novel peptide, terminating after additional 51 amino acids. Thus, contrary to the expectation based on the erythrocytosis phenotype, the EPO ΔG deletion was predicted to be a loss-of-function mutation.Since we had no access to patient's kidney or liver tissues where Epo is produced, we used the CRISPR technique to introduce the ΔG mutation into the EPO gene into Hep3B cells, a human hepatoma cell line that expresses EPO . We obtained two Hep3B single-cell derived clones (ΔG1 and ΔG4) that were homozygous for the EPO ΔG mutation and measured Epo protein in the culture supernatants. We found that these supernatants contained 8-10 times more Epo than parental Hep3B cells or controls, as determined by ELISA (Figure 1A), and were also capable of stimulating the growth of an Epo-dependent cell line (BaF3- EpoR), demonstrating biological activity (Figure 1B). Thus, the ΔG deletion introduced into the EPO gene locus in Hep3B cells behaved as a gain-of-function mutation.To decipher the mechanism of how the ΔG mutation was able to produce the excess of Epo protein, we searched for alternative EPO mRNAs by 5'-RACE. In addition to the expected transcripts originating from the physiologic promoter (P1) upstream of exon 1, we discovered two types of alternative mRNAs that initiate in intron 1 of EPO. Both initiatied from a putative alternative promoter (P2) in intron 1 that contains two GATA motifs. In addition to Hep3B ΔG clones, P2 transcripts were also detected in parental Hep3B cells and also in mRNA from normal kidney and liver.To determine which transcripts are capable of producing Epo, we transfected HEK293 cells with cDNAs representing P1 or P2 transcripts with or without the ΔG mutation. Supernatants of cells transfected with P2 ΔG transcripts contained more Epo than cells transfected with the wildtype P1 cDNA. These supernatants also stimulated the growth of Epo dependent BaF3- EpoR cells and supported erythroid colony formation of progenitors from human peripheral blood, demonstrating that P2 ΔG transcripts produce biologically active Epo protein.Analysis of the P2 mRNA sequences shows that the normally non-coding P2 transcripts through the ΔG single base deletion connect to the Epo coding sequence creating a functional signal peptide with a novel N-terminus, but retaining the physiologic Epo signal peptide cleavage site. These P2 ΔG transcripts are more abundant in liver and produce an excess of biologically active Epo by escaping the oxygen sensing regulation. Our data demonstrate for the first time mutation in EPO as a cause of familial erythrocytosis and provide an explanation of how the ΔG results in a gain-of-function mutation (Figure 1C).Figure 1 legend: A) Production of Epo protein by He3B cells carrying the ΔG mutation. Supernatants of parental Hep3B or CRISPR-modified Hep3B clones were collected and Epo protein was measured by Epo ELISA. The levels of Epo are given as a mean ± SD (n=3), p < 0.001 = *** as determined by one-way ANOVA. B) Biological activity of Epo produced by parental Hep3B or CRISPR-modified Hep3B cells measured by a proliferation assay with BaF3-EpoR cell line. BaF3-EpoR cells were grown in serial dilutions of supernatants and cell numbers were assessed by Cell Titer-Glo Assay, (n=3). Serial dilutions of 2.5 IU/ml of recombinant human Epo were used for reference. C) Model and proposed mechanism for EPO overproduction by a single nucleotide deletion in exon 2 of the EPO gene. [Display omitted] DisclosuresWaage:Celgene, Takeda: Honoraria. Skoda:Novartis: Consultancy, Speakers Bureau; Shire: Speakers Bureau; Baxalta: Consultancy, Speakers Bureau.

Locust Hemolymph Conveys Erythropoietin-Like Cytoprotection via Activation of the Cytokine Receptor CRLF3.

The cytokine receptor-like factor 3 (CRLF3) is an evolutionary conserved class 1 cytokine receptor present in all major eumetazoan groups. Endogenous CRLF3 ligands have not been identified and the physiological responses mediated by mammalian CRLF3 are poorly characterized. Insect CRLF3 is activated by erythropoietin (Epo) and several related molecules that protect mammalian neurons from stress-induced apoptosis. However, insects neither express Epo nor “classical” Epo receptor. Cell-protective effects of insect hemolymph have been described for several species. In this study, we explored the possibility that the endogenous CRLF3 ligand is contained in locust hemolymph. PCR analyses confirmed expression of crfl3-transcripts in neurons and hemocytes of Locusta migratoria and Tribolium castaneum. Survival of locust hemocytes in primary cultures was significantly increased by supplementation of culture medium with locust hemolymph serum. Locust primary neuron cultures were also protected by locust hemolymph, though preceding exposure to fetal bovine serum changed the hemolymph dose-dependency of neuroprotection. Direct comparison of 10% hemolymph serum with recombinant human Epo in its optimal neuroprotective concentration revealed equivalent anti-apoptotic effects on hypoxia-exposed locust neurons. The same concentration of locust hemolymph serum also protected hypoxia-exposed T. castaneum neurons. This indicates that the neuroprotective factor in locust hemolymph is sufficiently conserved in insects to allow activation of neuroprotective receptors in different species. Locust hemolymph-induced neuroprotection in both L. migratoria and T. castaneum was abolished after RNAi-mediated suppression of crlf3-expression. In summary, we report the presence of a conserved endogenous cytokine in locust hemolymph that activates CRLF3 and connected anti-apoptotic processes in hemocytes and neurons. Identification and characterization of the CRLF3 ligand will promote knowledge about cytokine evolution and may unravel cell-protective agents with potential clinical application.

P1379PLATELET/LYMPHOCYTE RATIO AS A MARKER OF ERYTHROPOIETIN RESPONSIVENESS IN END-STAGE RENAL DISEASE

Abstract Background and Aims Neutrophil/Lymphocyte Ratio (NLR) and Platelet/Lymphocyte Ratio (PLR) are closely associated with increased inflammation in end-stage renal disease, which often contributes to the severity of anemia in these patients. Erythropoiesis stimulating agents (ESA) have become a standard treatment of anemia in hemodialysis patients. Since some patients do not respond well to erythropoietin therapy (EPO) the aim of this study is to investigate if NLR and PLR as markers of increased inflammation, could be associated with resistance to EPO therapy. Method A total of 90 patients (36 females, 54 males; mean age 60,45 ±11,58) undergoing maintenance hemodialysis and who received recombinant human EPO therapy were examined. Patients' clinical characteristics, laboratory data, dialysis adequacy and the applied doses os EPO were examined in a period of 3 months. EPO hyporesponsiveness index (EHRI) was calculated as the weekly dose of EPO divided by kilograms of body weight divided by the hemoglobin level. Results Obtained results show a statistically significant correlation of moderate-intensity between EHRI and NLR ( r = 0.497, p &amp;lt; 0.01) as well as a negative correlation of moderate-intensity between EHRI and hemoglobin levels (Hgb) (r = -0.403, p &amp;lt; 0.01). When it comes to the connection of NLR and PLR with logarithmically converted EHRI values, the results show that there is no statistically significant correlation between NLR and EHRI. Comparison of PLR among 25th, 50th and 75th percentile of EHRI showed that PLR levels increased going from the 25th towards the 75th percentile (p &amp;lt; 0.01). Post hoc analysis indicated that there is also a statistically strong connection for the 25th i 50th percentile (&amp;lt;0 .05) and furthermore for the 50th and 75th percentile (&amp;lt; 0.05). Conclusion PLR was found to be superior to NLR in terms of evaluating ESA therapy resistance. PLR could be used as a predictor of ESA therapy response.

Tracking the ancestral functions of erythropoietin: neuroprotection &amp; mitochondria

It has long been thought that erythropoietin (Epo) is exclusively involved in erythropoiesis, allowing erythroid progenitor cells to survive and mature through their antiapoptotic action. We now know that Epo in mammals has also other functions in the brain, playing key roles in the development, maintenance, protection, and repair of the nervous system. However, the recombinant human Epo (rhEpo) has neuroprotective effects in orthoptera insects (such as grasshoppers), and this effect appears to be mediated by the cytokine receptor‐like factor 3 (CRLF3), raising interesting questions about the evolutionary origin of the Epo signaling pathway and its role in invertebrate species. Taking into account that: 1) Epo in mammals modulates the mitochondrial oxidative phosphorylation and the production of reactive oxygen species (ROS) in several tissues, including the brain; and 2) that insects appeared during a geological period (Cambrian explosion) in which the atmospheric O2 was increasing and required the implementation of antioxidant systems at the cellular level; here we tested the hypothesis that activation of the “Epo‐like” system in the brain domestic crickets (Acheta domesticus) exposed to 6 % of hypoxia during 5 days, modulates mitochondrial functions for preventing against oxidative damages. To do so, we used our oxygraph‐2K system (OROBOROS) that measures the mitochondrial bioenergetics in saponin‐permeabilized tissue of 2 mg weight. Our preliminary results showed that rhEpo increased the survival of domestic crickets exposed to hypoxia by 20%. We showed also that, in normoxic animals, rhEpo increased the mitochondrial O2 consumption rate (OCR), but in hypoxic animals, rhEPO limited the increase of mitochondrial OCR. In parallel, rhEpo significantly decreased the production of ROS in hypoxia. These preliminary results suggest that rhEpo significantly improves cricket’s survival under hypoxia, by promoting a robust antioxidant effect through mitochondria. Our data also suggest that a neuroprotective “Epo‐like” endogenous molecule evolved during the “Cambrian explosion” from a urbilaterian (common to vertebrates and invertebrates) ancestor.Support or Funding InformationNatural Sciences and Engineering Research Council of Canada

Effect of Recombinant Human EPO on the Postoperative Neurologic Outcome in Pediatric Moyamoya Patients

Effect of Recombinant Human EPO on the Postoperative Neurologic Outcome in Pediatric Moyamoya Patients

Erythropoietin Induces miRNA210 by JAK2/STAT5 Signaling in PBMCs of End Stage Renal Disease Patients

Background: Anemia of Chronic Kidney Disease is associated with blunted response/resistance to Erythropoietin Stimulating Agents (ESA) in hemodialysis patients (HD). However, none of the molecules successful associated to ESA-responsiveness is now considered a valid therapeutic biomarker of Erythropoietin resistance. Methods: We performed evaluation of the level of specific plasma circulating miRNAs in blood samples of HD, in relation to ESA treatment, with a follow up of one year (T0-T3). Findings: We found significant lower circulating levels of all miRNAs analyzed at baseline (T0) in HD vs. Healthy Control (HC). The plasmatic levels of miRNA210 resulted negatively associated to Erythropoietin Resistance Index (ERI), and the variance of ΔmiRNA210 (miRNA210T3 minus miRNA210T0) explained percentage of ΔERI (ERIT3 minus ERIT0) variance. The Receiver Operating Characteristic analysis at T0, showed that miRNA210 could distinguish HD with positive or negative trend in ERI at T3. The recombinant human EPO induced release of miRNA210 from cultured PBMCs, through the activation of JAK2/STAT5 signaling, but no by the activation of the MAPK p38α and ERK1/2. In accordance, HD with negative ΔERI, showed higher level of p-JAK2, and nuclear translocation of p-STAT5 vs. patients with positive ΔERI or HC. Interpretation: The ESA treatment induces expression and release of miRNA210 from PBMCs. The magnitude of this process is negatively associated to ESA resistance. Findings: We highlighted that chronic HD significantly reduces the circulating level of the miRNAs evaluated; within the targets analyzed, the miRNA210 could be considered a plausible prognostic indicator of ESA responsiveness and index for anemia management. Funding Statment: This study was supported by grants from the Ministero dell’Universita e della Ricerca (MIUR). Declaration of Interests: All the authors declared no competing interests. Ethics Approval Statement: The study was approved by the local Ethics Committee (application number E2-02-2015).

Effects of erythropoietin on fibroblast growth factor 23 in mice and humans.

Erythropoietin (EPO) has been reported as a novel determinant of fibroblast growth factor 23 (FGF23) production; however, it is unknown whether FGF23 is stimulated by chronic exposure to EPO or by EPO administration in nonpolycystic chronic kidney disease (CKD) models. We analyzed the effects of chronic EPO on FGF23 in murine models with chronically high EPO levels and normal kidney function. We studied the effects of exogenous EPO on FGF23 in wild-type mice, with and without CKD, injected with EPO. Also, in four independent human CKD cohorts, we evaluated associations between FGF23 and serum EPO levels or exogenous EPO dose. Mice with high endogenous EPO have elevated circulating total FGF23, increased disproportionately to intact FGF23, suggesting coupling of increased FGF23 production with increased proteolytic cleavage. Similarly, in wild-type mice with and without CKD, a single exogenous EPO dose acutely increases circulating total FGF23 out of proportion to intact FGF23. In these murine models, the bone marrow is shown to be a novel source of EPO-stimulated FGF23 production. In humans, serum EPO levels and recombinant human EPO dose are positively and independently associated with total FGF23 levels across the spectrum of CKD and after kidney transplantation. In our largest cohort of 680 renal transplant recipients, serum EPO levels are associated with total FGF23, but not intact FGF23, consistent with the effects of EPO on FGF23 production and metabolism observed in our murine models. EPO affects FGF23 production and metabolism, which may have important implications for CKD patients.

Erythropoietin signaling increases neurogenesis and oligodendrogenesis of endogenous neural stem cells following spinal cord injury both invivo and invitro.

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

Erythropoietin reduces experimental autoimmune encephalomyelitis severity via neuroprotective mechanisms

BackgroundTreatment with erythropoietin (Epo) in experimental autoimmune encephalomyelitis (EAE), the rodent model of multiple sclerosis (MS), has consistently been shown to ameliorate disease progression and improve overall outcome. The effect has been attributed to modulation of the immune response and/or preservation of the central nervous system (CNS) tissue integrity. It remains unclear, however, if (a) Epo acts primarily in the CNS or the periphery and if (b) Epo’s beneficial effect in EAE is mainly due to maintaining CNS tissue integrity or to modulation of the immune response. If Epo acts primarily by modulating the immune system, where is this modulation required? In the periphery, the CNS or both?MethodsTo address these questions, we used two well-characterized transgenic mouse strains that constitutively overexpress recombinant human Epo (rhEpo) either systemically (tg6) or in CNS only (tg21) in a MOG-induced EAE model. We assessed clinical severity, disease progression, immunomodulation, and CNS tissue integrity, including neuronal survival.ResultsAlthough disease onset remained unaffected, EAE progression was alleviated in transgenic animals compared to controls with both lines performing equally well showing that expression of Epo in the periphery is not required; Epo expression in the CNS is sufficient. Immunomodulation was observed in both strains but surprisingly the profile of modulation differed substantially between strains. Modulation in the tg21 strain was limited to a reduction in macrophages in the CNS, with no peripheral immunomodulatory effects observed. In contrast, in the tg6 strain, macrophages were upregulated in the CNS, and, in the periphery of this strain, T cells and macrophages were downregulated. The lack of a consistent immunomodulatory profile across both transgenic species suggests that immunomodulation by Epo is unlikely to be the primary mechanism driving amelioration of EAE. Finally, CNS tissue integrity was affected in all strains. Although myelin appeared equally damaged in all strains, neuronal survival was significantly improved in the spinal cord of tg21 mice, indicating that Epo may ameliorate EAE predominantly by protecting neurons.ConclusionsOur data suggests that moderate elevated brain Epo levels provide clinically significant neuroprotection in EAE without modulation of the immune response making a significant contribution.

Efficacy of Shengxue Mixture Combined with Intraosseous Infusion for Treatment of Aplastic Anemia

To evaluate the efficacy and safety of Shengxue mixture combined with intraosseous blood infusion for treatment of aplastic anemia patients. From 2011 to 2015, Institute of blood diseases of Shaanxi Medical University admitted 53 patients with aplastic anemia. The patients were treated with shengxue mixture 200 ml, orally, twice a day. Stanozolol tablets, Adult 2 mg, three times a day, mycophenolate mofetil 1.0 g, twice a day. Intraosseous infusion of the following medicine were administered in patients: recombinant human EPO 10000 U, recombinant human G-CSF 450 µg, recombinant human IL-11 4.5 mg, dexmethasone 20 mg, once a week, a total of four times. One month later, the blood cell counts and bone marrow biopsy were performed. Consolidation treatment continued for 3 to 6 months after discharge, and therapeutic effect was observed and followed-up for more than a year. After one month of treatment, 40 patients were basically cured (75.47%), 8 patients were remitted(15.09%), Hemoglobin level, white blood cell count and platelet count were significantly improved after treatment (P<0.01). The overall response rate was 90.57%(48 patients). Patients with bone marrow hyperplasia was 46 (86.79%), versus 9(16.98%) before treatment. There was a difference (P<0.05). After 3 to 6 months of treatment, 40 patients were cured (75.47%); 8 patients were remitted(15.09%); 3 patients were obviously improved(5.66%); 2 patients were ineffective(3.77%). The overall response rate was 96.23%(51 cases). No obvious side effects were observed. No patients were relapsed after one year. Shengxue mixture combined with Intraosseous infusion is a fast, efficient, safe method for the treatment of aplastic anemia.

Biologically active recombinant human erythropoietin expressed in hairy root cultures and regenerated plantlets of Nicotiana tabacum L.

Hairy root culture is a potential alternative to conventional mammalian cell culture to produce recombinant proteins due to its ease in protein recovery, low costs and absence of potentially human pathogenic contaminants. The current study focussed to develop a new platform of a hairy root culture system from Nicotiana tabacum for the production of recombinant human EPO (rhEPO), which is regularly produced in mammalian cells. The human EPO construct was amplified with C-terminal hexahistidine tag from a cDNA of Caco-2 cells. Two versions of rhEPO clones, with or without the N-terminal calreticulin (cal) fusion sequence, were produced by cloning the amplified construct into gateway binary vector pK7WG2D. Following Agrobacterium rhizogenes mediated transformation of tobacco explants; integration and expression of constructs in hairy roots were confirmed by several tests at DNA, RNA and protein levels. The amount of intracellular rhEPO from hairy root cultures with cal signal peptide was measured up to 66.75 ng g-1 of total soluble protein. The presence of the ER signal peptide (cal) was essential for the secretion of rhEPO into the spent medium; no protein was detected from hairy root cultures without ER signal peptide. The addition of polyvinylpyrrolidone enhanced the stabilization of secreted rhEPO leading to a 5.6 fold increase to a maximum concentration of 185.48 pg rhEPOHR g-1 FW hairy root cultures. The rhizo-secreted rhEPO was separated by HPLC and its biological activity was confirmed by testing distinct parameters for proliferation and survival in retinal pigment epithelial cells (ARPE). In addition, the rhEPO was detected to an amount 14.8 ng g-1 of total soluble leaf protein in transgenic T0 generation plantlets regenerated from hairy root cultures with cal signal peptide.

The Insect Ortholog of the Human Orphan Cytokine Receptor CRLF3 Is a Neuroprotective Erythropoietin Receptor.

The cytokine erythropoietin (Epo) mediates various cell homeostatic responses to environmental challenges and pathological insults. While stimulation of vertebrate erythrocyte production is mediated by homodimeric “classical” Epo receptors, alternative receptors are involved in neuroprotection. However, their identity remains enigmatic due to complex cytokine ligand and receptor interactions and conflicting experimental results. Besides the classical Epo receptor, the family of type I cytokine receptors also includes the poorly characterized orphan cytokine receptor-like factor 3 (CRLF3) present in vertebrates including human and various insect species. By making use of the more simple genetic makeup of insect model systems, we studied whether CRLF3 is a neuroprotective Epo receptor in animals. We identified a single ortholog of CRLF3 in the beetle Tribolium castaneum, and established protocols for primary neuronal cell cultures from Tribolium brains and efficient in vitro RNA interference. Recombinant human Epo as well as the non-erythropoietic Epo splice variant EV-3 increased the survival of serum-deprived brain neurons, confirming the previously described neuroprotective effect of Epo in insects. Moreover, Epo completely prevented hypoxia-induced apoptotic cell death of primary neuronal cultures. Knockdown of CRLF3 expression by RNA interference with two different double stranded RNA (dsRNA) fragments abolished the neuroprotective effect of Epo, indicating that CRLF3 is a crucial component of the insect Epo-responsive receptor. This suggests that a common urbilaterian ancestor of the orphan human and insect cytokine receptor CRLF3 served as a neuroprotective receptor for an Epo-like cytokine. Our work also suggests that vertebrate CRLF3, like its insect ortholog, might represent a tissue protection-mediating receptor.

Experimental study on EPO treatment of model rats with infection-induced acute liver injury

Objective: To study the effect of EPO therapy on liver injury, inflammation, oxidative stress and cell apoptosis in model rats with infection-induced acute liver injury. Methods: SD rats were selected and randomly divided into Sham group, sepsis group (CLP group) and EPO intervention group (EPO group), the cecal ligation and puncture was adopted to establish sepsis models and 5000IU/kg human recombinant EPO was provided for intervention. 24 hours after intervention, serum levels of liver injury molecules, inflammatory factors and oxidative stress molecules as well as liver tissue levels of oxidative stress molecules and cell apoptosis molecules were detected. Results: Serum ALT, AST, TNF-α, IFN-γ, IL-1β, IL-6, IL-8, MDA and AOPP levels, liver tissue Nrf2, ARE, MDA and AOPP levels as well as Bax, Caspase-9 and Caspase-3 mRNA expression of CLP group were significantly higher than those of Sham group while liver tissue HO-1 and SOD levels as well as Bcl-2 mRNA expression were significantly lower than those of Sham group; serum ALT, AST, TNF-α, IFN-γ, IL-1β, IL-6, IL-8, MDA and AOPP levels, liver tissue MDA and AOPP levels as well as Bax, Caspase-9 and Caspase-3 mRNA expression of EPO group were significantly lower than those of CLP group while liver tissue Nrf2, ARE, HO-1 and SOD levels as well as Bcl-2 mRNA expression were significantly higher than those of CLP group. Conclusions: EPO therapy could reduce liver injury and inhibit inflammation, oxidative stress and cell apoptosis in model rats with infection-induced acute liver injury.

Erythropoietin-Mediated Neuroprotection in Insects Suggests a Prevertebrate Evolution of Erythropoietin-Like Signaling.

The cytokine erythropoietin (Epo) mediates protective and regenerative functions in mammalian nervous systems via activation of poorly characterized receptors that differ from the "classical" homodimeric Epo receptor expressed on erythroid progenitor cells. Epo genes have been identified in vertebrate species ranging from human to fish, suggesting that Epo signaling evolved earlier than the vertebrate lineage. Studies on insects (Locusta migratoria, Chorthippus biguttulus, Tribolium castaneum) revealed Epo-mediated neuroprotection and neuroregeneration. Recombinant human Epo (rhEpo) prevents apoptosis by binding to a janus kinase-associated receptor, stimulation of STAT transcription factors, and generation of factors that prevent the activation of proapoptotic caspases. Insect neurons were also protected by a neuroprotective but nonerythropoietic Epo splice variant, suggesting similarity with mammalian neuroprotective but not with homodimeric "classical" Epo receptors. Additionally, rhEpo promotes the regeneration of neurites in primary cultured insect brain neurons and after nerve crush in an in vivo preparation. In contrast to neuroprotective and regenerative effects shared with mammalian species, no evidence for a role of Epo signaling in the regulation of neuro- or gliogenesis was found in insects. Similar structural and functional characteristics of the Epo binding receptors, partly shared transduction pathways that prevent apoptosis and the functional implication in neuroprotective and neuroregenerative processes in both mammalian and insect species, suggest that Epo-like signaling was already established in their last common ancestor. Originally functioning as a tissue-protective response to unfavorable physiological situations, cell injury, and pathogen invasion, Epo was later adapted as a humoral regulator of erythropoiesis in the vertebrate lineage.