• Molecules and Cells
• /
• 제38권6호
• /
• pp.496-505
• /
• 2015

A variant peak was detected in the analysis of RP-HPLC of rHu-EPO, which has about 7% relative content. Fractions of the main and the variant peaks were pooled separately and further analyzed to identify the molecular structure of the variant peak. Total mass analysis for each peak fraction using ESI-TOF MS shows differences in molecular mass. The fraction of the main peak tends to result in higher molecular masses than the fraction of the variant. The detected masses for the variant are about 600-1000 Da smaller than those for the main peak. Peptide mapping analysis for each peak fraction using Asp-N and Glu-C shows differences in O-glycopeptide profiles at Ser126. The O-glycopeptides were not detected in the fraction of the variant. It is concluded that the variant peak is non-O-glycosylated rHu-EPO and the main peak is fully O-glycosylated rHu-EPO at Ser126.

• Clinical and Experimental Pediatrics
• /
• 제53권10호
• /
• pp.898-908
• /
• 2010

Purpose: The neuroprotective effects of erythropoietin (EPO) have been recently shown in many animal models of brain injury, including hypoxic-ischemic (HI) encephalopathy, trauma, and excitotoxicity; however, limited data are available for such effects during the neonatal periods. Therefore, we investigated whether recombinant human EPO (rHuEPO) can protect against perinatal HI brain injury via an antiapoptotic mechanism. Methods: The left carotid artery was ligated in 7-day-old Sprague-Dawley (SD) rat pups ($in$ $vivo$ model). The animals were divided into 6 groups: normoxia control (NC), normoxia sham-operated (NS), hypoxia only (H), hypoxia+vehicle (HV), hypoxia+rHuEPO before a hypoxic insult (HE-B), and hypoxia+rHuEPO after a hypoxic insult (HE-A). Embryonic cortical neuronal cell culture of SD rats at 18 days gestation ($in$ $vitro$ model) was performed. The cultured cells were divided into 5 groups: normoxia (N), hypoxia (H), and 1, 10, and 100 IU/mL rHuEPO-treated groups. Results: In the $in$ $vivo$ model, Bcl-2 expressions in the H and HV groups were lower than those in the NC and NS groups, whereas those in the HE-A and HE-B groups were greater than those of the H and HV groups. The expressions of Bax and caspase-3 and the ratio of Bax/Bcl-2 were in contrast to those of Bcl-2. In the $in$ $vitro$ model, the patterns of Bcl-2, Bax, and caspase-3 expression and Bax/Bcl-2 ratio were similar to the results obtained in the in vivo model. Conclusion: rHuEPO exerts neuroprotective effect against perinatal HI brain injury via an antiapoptotic mechanism.

• Journal of Microbiology and Biotechnology
• /
• 제23권5호
• /
• pp.699-706
• /
• 2013

We have previously reported that N-acetylcysteine (NAC) not only delayed apoptosis but also enhanced the production of recombinant erythropoietin (EPO) in Chinese hamster ovary (CHO) cell culture. To investigate the production enhancement mechanism, the effects of similar thiol-reducing agents were studied. Intriguingly, all mild reducing agents examined including mercaptoethanesulfonic acid (MESNA), thiolactic acid (TLA), and thioglycolate (TG) were shown to block apoptosis and increase EPO production. A pulse-chase study of EPO secretion revealed that all four thiol-reducing agents increased the EPO secretion rate; among them TLA showed the highest rate. In terms of product quality, the sialic acid content of the glycoprotein is one of the most important factors. It was reported that a number of glycoproteins produced by CHO cells often have incomplete sialylation, particularly under high-producing conditions. Human ${\alpha}2,3$-sialyltransferase (${\alpha}2,3$-ST) was introduced into EPO-producing CHO cells in order to compensate for the reduced sialylation during supplementation with NAC. When ${\alpha}2,3$-ST was expressed in the presence of NAC, reduced sialylation was restored and an even more sialylated EPO was produced. Thus, our study is significant in that it offers increased EPO production while still allowing the prevention of decreased sialylation of EPO.

• 한국임상약학회지
• /
• 제21권2호
• /
• pp.122-130
• /
• 2011

Objective: Although recombinant human erythropoietin (rhEPO) has revolutionized the treatment of anemia in chronic kidney disease (CKD) receiving hemodialysis (HD) with no need of blood transfusion, some patients have a blunted or appear to be resistant to rhEPO. There is a controversy in the causes of rhEPO resistance in maintenance HD patients with anemia. This study is to examine current anemia treatment outcomes and the factors influencing the rhEPO responsiveness in HD patient with CKD. Methods: The clinical parameters or factors relating to erythrompoietin treatment outcomes and erythropoietin responsiveness were collected from the HD patients in two large dialysis centers for three months. The collected paramenters included serum iron, total iron biding capacity (TIBC), transferrin saturation rate, ferritin, albumin, intact PTH, C-reactive protein (CRP), nPCR and medications such as an angiotensin converting enzyme inhbitor, an angiotension II receptor blocker and an HMG-CoA reductase inhibitor (HMG-CoA RI). The data were analyzed to examine the degree of acheiveing the anemia treatment goal and factors relating to ERI. Results: Among total 111 patients, 42 (42.3%) and 47 (37.8%) patients achieved the target Hct and Hb based on the Health Insurance Review and Assessment Services (HIRA) reimbursement criteria. In the higher ERI group (upper quartile), the patients had higher CRP levels (0.5 mg/dl) (p=0.0096), and lower TIBC score (<$240{\mu}g/dl$) (p=0.0027), and less patients were taking HMG-CoA RI (p=0.0019). Male patients (p=0.0204), patients with high TIBC score ($R^2$=0.084, p=0.0021) and patients taking HMG-CoA RI (p=0.0052) required to administer less dose of rhEPO meaning higher erythropoietin responsiveness. Conclusion: Less than 50% of CKD patients were achieving the goals of anemia by erythropoietin administration in large hospitals in Korea even though the goals were lower than those of NKF-K/DOQI practice guideline. The factors influencing ERI were sex, TIBC and HMG-CoA RI administration status, and neither an ACEI nor an ARB did not influence ERI.

• Biomolecules & Therapeutics
• /
• 제28권2호
• /
• pp.152-162
• /
• 2020

Cerebral ischemia exhibits a multiplicity of pathophysiological mechanisms. During ischemic stroke, the reactive oxygen species (ROS) concentration rises to a peak during reperfusion, possibly underlying neuronal death. Recombinant human erythropoietin (EPO) supplementation is one method of treating neurodegenerative disease by reducing the generation of ROS. We investigated the therapeutic effect of PEGylated EPO (P-EPO) on ischemic stroke. Mice were administered P-EPO (5,000 U/kg) via intravenous injection, and middle cerebral artery occlusion (MCAO) followed by reperfusion was performed to induce in vivo ischemic stroke. P-EPO ameliorated MCAO-induced neurological deficit and reduced behavioral disorder and the infarct area. Moreover, lipid peroxidation, expression of inflammatory proteins (cyclooxygenase-2 and inducible nitric oxide synthase), and cytokine levels in blood were reduced by the P-EPO treatment. In addition, higher activation of nuclear factor kappa B (NF-κB) was found in the brain after MCAO, but NF-κB activation was reduced in the P-EPO-injected group. Treatment with the NF-κB inhibitor PS-1145 (5 mg/kg) abolished the P-EPO-induced reduction of infarct volume, neuronal death, neuroinflammation, and oxidative stress. Moreover, P-EPO was more effective than EPO (5,000 U/kg) and similar to a tissue plasminogen activator (10 mg/kg). An in vitro study revealed that P-EPO (25, 50, and 100 U/mL) treatment protected against rotenone (100 nM)-induced neuronal loss, neuroinflammation, oxidative stress, and NF-κB activity. These results indicate that the administration of P-EPO exerted neuroprotective effects on cerebral ischemia damage through anti-oxidant and anti-inflammatory properties by inhibiting NF-κB activation.

• Clinical and Experimental Pediatrics
• /
• 제60권6호
• /
• pp.181-188
• /
• 2017

Purpose: Hypoxic-ischemic encephalopathy is a significant cause of neonatal morbidity and mortality. Erythropoietin (EPO) is emerging as a therapeutic candidate for neuroprotection. Therefore, this study was designed to determine the neuroprotective role of recombinant human EPO (rHuEPO) and the possible mechanisms by which mitogen-activated protein kinase (MAPK) signaling pathway including extracellular signal-regulated kinase (ERK1/2), JNK, and p38 MAPK is modulated in cultured cortical neuronal cells and astrocytes. Methods: Primary neuronal cells and astrocytes were prepared from cortices of ICR mouse embryos and divided into the normoxic, hypoxia (H), and hypoxia-pretreated with EPO (H+EPO) groups. The phosphorylation of MAPK pathway was quantified using western blot, and the apoptosis was assessed by caspase-3 measurement and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Results: All MAPK pathway signals were activated by hypoxia in the neuronal cells and astrocytes (P<0.05). In the neuronal cells, phosphorylation of ERK-1/-2 and apoptosis were significantly decreased in the H+EPO group at 15 hours after hypoxia (P<0.05). In the astrocytes, phosphorylation of ERK-1/-2, p38 MAPK, and apoptosis was reduced in the H+EPO group at 15 hours after hypoxia (P<0.05). Conclusion: Pretreatment with rHuEPO exerts neuroprotective effects against hypoxic injury reducing apoptosis by caspase-dependent mechanisms. Pathologic, persistent ERK activation after hypoxic injury may be attenuateed by pretreatment with EPO supporting that EPO may regulate apoptosis by affecting ERK pathways.

• Neonatal Medicine
• /
• 제16권2호
• /
• pp.221-233
• /
• 2009

목 적 : 신장에서 분비되어 적혈구를 생산하는 빈혈제로 알려진 에리스로포이에틴(Erythropoietin, EPO)은 단순히 피를 만드는 조혈기능 뿐 아니라 최근 신경계 보호 및 신경강화 효과가 있다고 발표되고 있지만 주산기 가사로 인한 저산소성 허혈성 뇌병증의 치료제로서 그 기전이 명확하게 밝혀지지 않았다. 저자들은 유전자 재조합 인 에리스로포이에틴(recombinant Human EPO, rHuEPO)을 이용하여 주산기 저산소성 허혈성 뇌병증의 치료제로서 N-methyl-D-aspartate (NMDA) 수용체와 관련된 흥분성 독성작용을 통한 조절 등 그 기전을 알아보고자 하였다. 방 법 : 재태기간 19일된 태아 백서의 대뇌피질 세포를 배양하여 정상산소군은 5% $CO_2$ 배양기(95% air, 5% $CO_2$)에 두었고, 저산소군과 농도별 뇌손상 전 rHuEPO 투여군(1, 10, 100 IU/mL)은 1% $O_2$ 배양기(94% $N_2$, 5% $CO_2$)에서 6시간 동안 뇌세포손상을 유도하였다. 세포성장과 생존력을 평가하기 위해 MTT 실험을 시행하였다. 동물 모델에서는 생후 7일된 신생백서의 좌측 총 경동맥을 결찰한 후 6개 군; 정상산소군, sham-operated군, 저산소-허헐성군, 저산소-허헐성+vehicle군, 저산소-허헐성 손상 전 rHuEPO 투여군, 저산소-허헐성 손상 후 rHuEPO 투여군으로 나누었고, 저산소-허헐성 손상은 특별히 제작한 통속에서 2시간 동안 8% $O_2$ (8% $O_2$, 92% $N_2$)에 노출시켰다. rHuEPO은 뇌손상 전후 30분에 체중 kg당 1000 IU를 투여하였고, 저산소-허헐성 손상 후 7일째 조직을 실험하였다. 적출한 조직으로 H&E 염색을 하여 뇌손상을 형태학적으로 관찰하였다. 세포배양 및 동물실험에서 NMDA 수용체의 아단위인 NR1, NR2A, NR2B, NR2C, NR2D를 이용하여 실시간 중합효소연쇄반응을 실시하였다. 결 과 : 저산소군에서 세포 생존률은 정상산소군보다 60% 감소하였으며, rHuEPO 투여군(1, 10 IU/mL)은 80% 증가하였다. rHuEPO 투여군(100 IU/mL)은 회복되지 않았다. 우측 반구 대비 좌측 반구의 범위는 정상산소군 98.9%, sham-operated군 99.1%, 저산소-허헐성군 57.1%, 저산소-허헐성+vehicle군 57.0%, 저산소-허헐성 손상 전 rHuEPO 투여군 87.6%, 저산소-허헐성 손상 후 rHuEPO 투여군 91.6%으로 나타났다. NMDA 수용체의 아단위 생체외 실험에서 실시간 중합효소연쇄반응의 결과 NMDA 수용체 아단위 mRNA의 발현은 rHuEPO 투여군에서 저산소군보다 모두 증가하였다. 결 론 : 본 연구에서 rHuEPO은 흥분성 독성작용과 관련되어 NMDA 수용체를 조절하면서 저산소성 허헐성 뇌손상을 보호하는 것을 알 수 있었다.

• Molecules and Cells
• /
• 제27권5호
• /
• pp.577-582
• /
• 2009

The development of a high-throughput functional genomic screening provides a novel and expeditious approach in identifying critical genes involved in specific biological processes. Here we describe a cell-based cDNA screening system to identify the transcription activators of BiP, an endoplasmic reticulum (ER) chaperone protein. BiP promoter contains the ER stress element which is commonly present in the genes involved in unfolded protein response (UPR) that regulates protein secretion in cells. Therefore, the positive regulators of BiP may also be utilized to improve the recombinant protein production through modulation of UPR. Four BiP activators, including human UDP-glucose:glycoprotein glucosyltransferase 1 (HUGT1), are identified by the cDNA screening. Overexpression of HUGT1 leads to a significant increase in the production of recombinant erythropoietin, interferon ${\gamma}$, and monoclonal antibody in HEK293 cells. Our results demonstrate that the cDNA screening for BiP activators may be effective to identify the novel BiP regulators and HUGT1 may serve as an ideal target gene for improving the recombinant protein production in mammalian cells.

• 대한치과마취과학회지
• /
• 제12권1호
• /
• pp.25-31
• /
• 2012

We report a case of 15 year-old Jehovah's Witness patient with mild anemia who underwent a successful orthognathic two-jaw surgery. Jehovah's Witness patients refuse transfusion of blood or blood products even in life threatening situations. The use of recombinant human erythropoietin and iron supplement increased hemoglobin during preoperative period. Intraoperatively, meticulous surgical hemostasis, acute normovolemic hemodilution and induced hypotension enabled the completion of the operation without the use of blood products.

• 한국환경성돌연변이발암원학회지
• /
• 제16권2호
• /
• pp.103-108
• /
• 1996

The mutagenic potential of rHu-EPO was evaluated using the short-term genotoxicity tests including Ames, chromosome aberration and micronuclei tests. In Salmonella typhimurium assay, rHu-EPO did not show any mutagenic response in the absence or presence of S9 mix with TA98, TA100, TA1535, and TA1537. In chromosome aberration test, rHu-EPO did not show any significant effect on Chinese Hamster Ovary(CHO) cells compared with control. In micronucleus test using male ICR mice, a dose-dependence increase in the frequency of micronucleuted polychromatic erythrocytes(MNPCEs) was observed in bone marrow cells treated with rHu-EPO. However, it was related to the secondary effect of rHu-EPO and the number of MNPCEs was equal to spontaneous frequency. These results indicate that rHu-EPO does not show any positive response in short-term genotoxicity assays.