• Reproductive and Developmental Biology
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• 제29권2호
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• pp.69-73
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• 2005

The hematopoietic growth factor erythropoietin (EPO) is required for the maintenance, proliferation, and differentiation of the stem cells that produce erythrocytes. To analyse the biological activity of the recombinant human EPO (rec-hEPO), we have cloned the EPO cDNA and genomic DNA and produced rec-hEPO in the CHO cell lines. The growth and differentiation of EPO-dependent human leukemic cell line (F36E) were used to measure cytokine dependency and in vitro bioactivity of rec-hEPO. MIT assay values were increased by survival of F36E cells at 24h or 72h. The hematocrit and RBC values were increased by subcutaneous injection of 20 IU (in mice) and 100IU(in rats) rec-hEPO. Hematocrit values remarkably increased at $13.2\%$ (in mice) and $12.2\%$ (in rats). The pharmacokinetic behavior with injection of 6 IU of rec-hEPO remained detectable after 24 h in all mice tested. The highest peat appeared at 2h after injection. The long half-life of rec-hEPO is likely to confer clinical advantages by allowing less frequent dosing in patients treated for anemia. These data demonstratethat ree-hEPO produced in this study has a potent activity in vivo and in vitro. The results also suggest that biological activity of ree-hEPO could be remarkably enhanced by genetic engineering that affects the potential activity, including mutants with added oligosaccharide chain and designed to produce EPO-EPO fusion protein.

• Journal of Korean Neurosurgical Society
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• 제66권3호
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• pp.258-262
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• 2023

Germinal matrix-intraventricular hemorrhage (GM-IVH) is among the devastating neurological complications with mortality and neurodevelopmental disability rates ranging from 14.7% to 44.7% in preterm infants. The medical techniques have improved throughout the years, as the morbidity-free survival rate of very-low-birth-weight infants has increased; however, the neonatal and long-term morbidity rates have not significantly improved. To this date, there is no strong evidence on pharmacological management on GM-IVH, due to the limitation of well-designed randomized controlled studies. However, recombinant human erythropoietin administration in preterm infants seems to be the only effective pharmacological management in limited situations. Hence, further high-quality collaborative research studies are warranted in the future to ensure better outcomes among preterm infants with GM-IVH.

• Toxicological Research
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• 제21권3호
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• pp.227-234
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• 2005

• Molecules and Cells
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• 제23권1호
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• pp.17-22
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• 2007

We have expressed human erythropoietin (EPO) in transgenic mice using a recombinant EPO cDNA combined with a partial TPO construct. The gene was microinjected using standard techniques and five mice were detected as transgenic by PCR and further used as founders. The life span of the transgenic founders was much shorter than that of their normal littermates. Most of the tissues of the transgenic founders contained human EPO transcripts as judged by RT-PCR. Especially high expression levels were seen in the liver and lung. EPO protein levels in serum were examined by ELISA and ranged from 266-414 mIU/ml. The number of red blood cell, white blood cell and hemoglobin in the hEPO transgenic mice was higher than in normal mice. These results indicate that overexpression of hEPO is deleterious and can provoke lung failure and erythrocytosis.

• Reproductive and Developmental Biology
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• 제34권4호
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• pp.289-297
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• 2010

Erythropoietin (EPO) is a glycoprotein hormone secreted from primarily cells of the peritubular capillary endothelium of the kidney, and is responsible for the regulation of red blood cell production. We constructed and expressed dimeric cDNAs in Chinease hamster ovary (CHO) cells encoding a fusion protein consisting of 2 complete human EPO domains linked by a 2-amino acid linker (Ile-Asp). We described the activity of dimeric hyperglycosylated EPO (dHGEPO) mutants containing additional oligosaccharide chains and characterized the function of glycosylation. No dimeric proteins with mutation at the $105^{th}$ amino acid were found in the cell medium. Growth and differentiation of the human EPO-dependent leukemiae cell line (F36E) were used to measure cytokine dependency and in vitro bioactivity of dHGEPO proteins. MIT assay at 24 h increased due to the survival of F36E cells. The dHGEPO protein migrated as a broad band with an average molecular mass of 75 kDa. The mutant, dHGEPO, was slightly higher than the wild-type (WT) dimeri-EPO band. Enzymatic N-deglycosylation resulted in the formation of a narrow band with a molecular mass twice of that of of monomeric EPO digested with an N-glycosylation enzyme. Hematocrit values were remarkably increased in all treatment groups. Pharmacokinetic analysis was also affected when 2.5 IU of dHGEPO were intravenously injected into the tails of the mice. The biological activity and half-life of dHGEPO mutants were enhanced as compared to the corresponding items associated the WT dimeric EPO. These results suggest that recombinant dHGEPO may be attractive biological and therapeutic targets.

• Biomolecules & Therapeutics
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• 제10권1호
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• pp.59-69
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• 2002

Recently, recombinant human erythropoietin (rHu-EPO) has been used to treat various types of anemia. YHB216 is a new rHu-EPO developed by Yuhan Research Institute. In this study, we investigated the single dose and 4-week repeated dose toxicity of YHB216 in Beagle dogs. In the single dose toxicity study, YHB216 was administered intravenously at single dose levels of 0 and 25,000 IU/kg to dogs (2 dogs/sex/group). There were no treament-related changes in survivals, clinical signs, body weight gain, hematological values, blood chemical values, and necropsy finding during experimental period. In the repeated dose toxicity study, YHB216 was administered intravenously to dogs for 4 weeks at the dose levels of 0, 100, 500, and 2,500IU／kg (3 dogs/sex／group). There were no toxicologically significant changes in clinical signs, body weights, food and water consumptions, ophthalmoscopy, urinalysis and blood chemistry. There were increased values of red blood cell, hemoglobin, and hematocrit at all treated groups. Spleen revealed increased weight and extramedullary hematopoiesis at 500 IU/kg or more. These changes are all considered to be Pharmacology-related effects and were recovered after 4-week recovery period. From these results, it is concluded that LD50 value was above 25,000 IU/kg in the single dose toxicity study of YHB216 in dogs and the no observed adverse effect level (NOAEL) was 100 IU/kg day in the repeated dose toxicity study of YHB216 in dogs.

• 한국가축번식학회지
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• 제26권2호
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• pp.95-104
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• 2002

본 연구는 사람의 조혈촉진 유전자(hEPO)가 도입된 형질전환 돼지를 생산하기 위해 사계절동안 수행하였다. 약 8∼15개월령의 순종의 랜드레이스 경산돈 및 미경산돈 42두는 유전자 미세주입을 위한 1세포기 단계의 수정란 채란 및 이식을 위해 사용하였으며, 발정동기화 및 과배란 방법은 PG 600 주입 후 9일간 매일 20mg의 altrenogest를 사료에 첨가하여 급여하였다. Altrenogest를 9일간 급여 후 1,500IU의 PMSG와 500IU의 hCG를 주입하므로서 과배란을 유도하였다. 미세주입을 위한 유전자는 mouse whey acidic protein(mWAP) 프로모터에 hEPO 유전자를 연결하여 준비하였으며, 호르몬 처리후 23두의 공란돈으로 부터 650개의 난자를 회수하였으며, 이 중 83.1%(540/650)는 DNA 미세주입을 위해 전핵을 관찰할 수 있는 1-세포기의 수정란이었다. 이중 유전자가 미세주입 된 543개의 난자를 19두의 수란돈에 이식하였으며 7두의 임신돈으로부터 47두의 자돈을 생산하였다. 생산된 자돈 47두로부터 꼬리조직으로부터 분리된 DNA의 PCR 검정 결과 수컷 1두가 형질전환 양성반응을 나타내어 2.13%의 형질전환율을 나타내었으며, 이러한 연구의 결과는 생체반응기(bioreactor)연구에 있어서 형질전환 돼지생산의 성공적이며 유용한 정보를 제공할 것으로 사료된다.

• BMB Reports
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• 제53권3호
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• pp.148-153
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• 2020

Erythropoietin and iron have individually shown beneficial effects on early-phase liver regeneration following partial hepatectomy (PHx); however, there are limited data on the combined effect on late-phase liver regeneration after PHx. Here we examined combined effects of recombinant human erythropoietin (rhEPO, 3,000 IU/kg) and iron isomaltoside (IIM, 40 mg/kg) on late-phase liver regeneration following PHx and investigated the possible underlying mechanism. Rats administrated with rhEPO showed significantly higher liver mass restoration, interleukin-6 (IL-6, a hepatocyte mitogen) levels, and Ki-67-positive hepatocytes on day 7 after PHx than saline-treated controls. These beneficial effects were further enhanced on days 7 and 14 by co-treatment with IIM. This combination also significantly improved liver function indices, such as increased albumin production and decreased bilirubin levels, but did not alter serum levels of toxic parameters, such as aspartate transaminase and alanine transaminase. This study demonstrates that the combination of rhEPO and IIM synergistically improves late-phase liver regeneration and function after PHx, probably by promoting IL-6-mediated hepatocyte proliferation without adverse effects. Thus, this combination treatment can be a potential therapeutic strategy for patients undergoing resection for hepatic malignancies.

• Biomolecules & Therapeutics
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• 제18권2호
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• pp.184-190
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• 2010

Clinical cases of pure red cell aplasia (PRCA) have been reported during the recombinant human erythropoietin (EPO) therapy for the anemia patients. PRCA is a rare hematological disorder leading to a severe anemia due to an almost complete stop of red blood cell production. Antibody (Ab)-associated PRCA is caused by the EPO-neutralizing Abs that eliminate the biological activity of EPO. In order to detect anti-EPO Abs in human sera, we performed conventional ELISA, directly coated bridging ELISA, and streptavidin coated bridging ELISA, and compared their sensitivity and specificity. Some false positive results were obtained in the conventional ELISA. One positive sample was detected successfully by streptavidin coated bridging ELISA, which was not appeared in the directly coated bridging ELISA. In conclusion, streptavidin coated bridging ELISA was substantially sensitive and specific format and one out of sixty-eight serum samples was proved to be anti-EPO positive.

• Toxicological Research
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• 제22권1호
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• pp.61-67
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• 2006

Changes in hematology and serum biochemistry after treatment of recombinant human erythropoietin (rHuEPO, HM10760) were screened in 4 male cynomolgus monkeys (Macaca fascicularis). Four monkeys, composed of a treatment group of HM10760 and a positive control group of $Aranesp^(R}$, were subcutaneously administered at same dose of $100{\mu}g/kg$. Both groups did not show any change in body weights and food consumption for 4 weeks compared with those of pretreatment. Both groups did not show any change in total leukocyte count (WBC) and platelet count, while both groups showed increased platelet distribution width (PDW) percentage in HM10760 group during a period from day 5 to day 59 and in $Aranesp^(R}$ group during a period from day 9 to day 26. Both groups showed increases in red blood cells (RBC), hemoglobin (HGB), and hematocrit (HCT) approximately 10 days after treatment compared with those of pretreatment (day 0). The increased levels of RBC, HGB, and HCT were much higher in HM10760 than in $Aranesp^(R}$ by the increases of $3.2%{\sim}12.5%$ for RBC, $3.8%{\sim}17.1%$ for HCT, and $1.85%{\sim}11%$ for HGB. Both groups showed increases in red cells distribution width (RDW) and reticulocyte (RET) compared with those of pretreatment, showing the highest peak from day 9. The increased level of RET lasted up to day 14 in $Aranesp^(R}$ group, while it lasted up to day 23 in HM10760 group. The increased level of RDW lasted up to day 59, it was much higher in HM10760 by the increase of $10.1%{\sim}17.6%$ than in $Aranesp^(R}$ group. In serum biochemistry, both groups showed a decrease in chloride level compared with those of pretreatment. These findings indicated that HM10760 increased RBC, HGB, HCT, RDW, and RET compared with those of pretreatment, and the increased levels were much higher in HM10760 than in $Aranesp^(R}$.