Update on the role and mechanism of erythropoietin receptor in acute kidney injury and repair or fibrosis / 生理学报

Acute kidney injury (AKI) is a common critical disease clinically with high morbility and mortality and some survival patients also progress to chronic kidney disease. Renal ischemia-reperfusion (IR) is one of the main causes of AKI, in which, its repair and potential fibrosis, apoptosis, inflammation and phagocytosis play important roles. During the progression of IR-induced AKI, the expression of erythropoietin homodimer receptor (EPOR)2 and EPOR and β common receptor formed heterodimer receptor (EPOR/βcR) is changed dynamically. Moreover, (EPOR)2 and EPOR/βcR may synergistically participate in renoprotection at the stage of AKI and early repair, whereas at the late stage of AKI, the (EPOR)2 induces renal fibrosis and the EPOR/βcR facilitates repair and remodelling. The underlying mechanism, signaling pathways and the different effect turning point of (EPOR)2 and EPOR/βcR have not been well defined. It has been reported that EPO, according to its 3D structure, derived helix B surface peptide (HBSP) and cyclic HBSP (CHBP) only bind to EPOR/βcR. Synthesized HBSP, therefore, provides an effective tool to distinguish the different roles and mechanisms of both receptors, with the (EPOR)2 promoting fibrosis or the EPOR/βcR leading to repair/remodelling at the late stage of AKI. This review discusses the similarities and differences of (EPOR)2 and EPOR/βcR in their impacts on apoptosis, inflammation and phagocytosis in AKI, repair and fibrosis post IR, associated mechanisms, signaling pathways and outcomes.

Effect of Silencing LNK Gene on the Expression of EPO and EPOR in THP-1 Cells / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of silencing LNK gene on the expression of EPO and EPOR in acute myeloid leukemia cells (THP-1).@*METHODS@#THP-1 cells were cultured. The lentivirus was used as a vector to silence the LNK gene stably. After 72 hours of infection, GFP expression level was detected by the fluorescent inverted microscopy. The lentiviral Infection efficiencies were monitored by flow cytometry. The LNK silencing effect was confirmed. The mRNA expressions of EPO and EPOR were detected by RT-PCR. The protein levels of LNK, EPO and EPOR were detected by Western blot.@*RESULTS@#At the time-point of 72 hours after lentivirus infection, the expression level of GFP was above 85% detected by fluorescent inverted microscopy. The infection efficiency was above 99% by flow cytometry. mRNA expressions of LNK, EPO and EPOR in LNK silencing group were signifycantly lower than those in control group (P＜0.05). The protein levels of LNK, EPO and EPOR in LNK silencing group were significantly lower than those in the control group (P＜0.05).@*CONCLUSION@#THP-1 cell line of LNK gene silencing has been successfully established,the LNK gene has been silenced, the expression of EPO and EPOR decrease, indicating that LNK may participate in the regulation of EPO and EPOR.

EPO and EPOR Expression in Patients with Acute Leukemia and Its Clinical Significance / 中国实验血液学杂志

OBJECTIVE@#To investigate the expression of erythropoietin (EPO) and erythropoietin receptor (EPOR) in patients with acute leukemia (AL) and its clinical significance.@*METHODS@#The levels of EPO and EPOR in plasma were determined by ELISA kit. mRNA expression levels of EPO and EPOR were determined by RT-RCR. The protein expression levels of EPO and EPOR were detected by Western blot.@*RESULTS@#The EPO protein levels in marrow plasma of ALL and AML group were significantly higher than those in the control group (P＜0.05), EPOR protein levels in ALL and AML group were significantly lower than those in the control group (P＜0.05). The mRNA levels of EPO and EPOR in ALL and AML groups were significantly higher than those in the control group (P＜0.05). The mRNA levels of EPO and EPOR in the high risk ALL and AML groups were significantly higher than those in the medium, low risk group and the control group (P＜0.05). The protein expression levels of EPO and EPOR in ALL and AML groups were significantly higher than that in control group (P＜0.05). The mRNA levels of EPO and EPOR in ALL and AML groups did not correlate with hemoglobin level and erythrocyte count (P＞0.05).@*CONCLUSION@#The expressions of EPO and EPOR is higher in ALL and AML patients. The expression levels of EPO and EPOR relate with the risk of ALL and AML. High risk patients have higher expression levels of EPO and EPOR, however, the expression levels of EPO and EPOR do not correlate with hemoglobin level and erythrocyte counting.

Eritropoyetina como agente eritropoyético y no eritropoyético: consideraciones terapéuticas / Erythropoietic and non-erythropoietic functions of erythropoietin: therapeutic considerations / Eritropoietina como agente eritropoiético e não eritropoiético: considerações terapêuticas / Erythropoietic and non-erythropoietic functions of erythropoietin: therapeutic considerations

La producción de glóbulos rojos es controlada continuamente para suplir la desaparición de las células envejecidas y garantizar un aporte de oxígeno adecuado a todo el organismo. La citoquina pleitrópica eritropoyetina (Epo), originalmente definida por su rol en la eritropoyesis para prevenir la muerte programada de progenitores eritroides en la médula ósea, ha demostrado un rol antiapoptótico protector sobre diversos tejidos no hematopoyéticos. A la reconocida eficacia del tratamiento con eritropoyetina recombinante humana (rhuEpo) para contrarrestar la anemia que acompaña a patologías muy diversas, se agregan algunos aspectos que impiden lograr los resultados terapéuticos esperados, ya sea por resistencia al tratamiento o por el desarrollo de efectos adversos. Con el fin de prevenir estos efectos, así como reducir las dosis de rhuEpo en tratamientos crónicos se han desarrollado nuevos agentes que presentan modificaciones estructurales de la Epo, o bien alteraciones en las propiedades/actividad de la Epo nativa. Dado que, actualmente, los resultados sobre los efectos de la Epo sobre morbilidad/ mortalidad en diversas patologías no están suficientemente claros, nuevas investigaciones serán útiles para resolver dudas sobre la efectividad de la eritropoyetina y sus derivados o agentes alternativos con el fin de proveer bases sólidas para el desarrollo de ensayos clínicos concluyentes.

Erythropoietin (Epo), the cytokine required for promoting erythropoiesis through the proliferation and differentiation of erythroid cells, has been reported to act as a pleiotropic cytokine beyond the hematopoietic system. In contrast with the potentially beneficial effects attributed to recombinant human erythropoietin (rhuEpo), research has advanced to indicate that mortality and morbidity rates are increased in some patient groups when treated with rhuEpo. Some cardiac and systemic conditions may predispose to adverse events, and other factors, such as proinflammatory agents, may lead to resistance to erythropoietin treatment. Many compounds are currently under investigation in order to avoid these unwanted effects and to reduce the rhuEpo dose during chronic therapies. They are either erythropoiesis-stimulating agents different from erythropoietin or structurally modified erythropoietins with altered properties and activities. In recent reports, contrasting data have raised several concerns regarding the effectiveness of erythropoietin treatment to prevent adverse events. Therefore, much investigation is needed to provide a solid basis for the development of conclusive clinical trials.

A produção de glóbulos vermelhos é controlada continuamente para suprir o desaparecimento das células envelhecidas e garantir uma contribuição de oxigênio adequado a todo o organismo. A citocina pleiotrópica eritropoietina (Epo), originalmente definida por seu papel na eritropoiese para prevenir a morte programada de progenitores eritroides na medula óssea, tem demonstrado um papel anti-apoptótico protetor sobre diversos tecidos não hematopoiéticos. Adicionam-se à reconhecida eficácia do tratamento com eritropoietina recombinante humana (rhuEpo), para contra-arrestar a anemia que acompanha patologias muito diversas, alguns aspectos que impedem alcançar os resultados terapêuticos esperados, quer seja por resistência ao tratamento ou pelo desenvolvimento de efeitos adversos. Com o fim de prevenir estes efeitos, bem como reduzir as doses de rhuEpo em tratamentos crônicos foram desenvolvidos novos agentes que apresentam modificações estruturais da Epo, ou então alterações nas propriedades/atividade da Epo nativa. Devido a que, atualmente, os resultados sobre os efeitos da Epo sobre morbidade/mortalidade em diversas patologias não estão suficientemente claros, novas pesquisas serão úteis para resolver dúvidas sobre a efetividade da eritropoietina e seus derivados ou agentes alternativos visando a fornecer bases sólidas para o desenvolvimento de ensaios clínicos concludentes.

Relationship between Injury Time and Expressions of EPO and Its Receptors in Rats Brain after Cerebral Injury / 法医学杂志

OBJECTIVE@#To explore the relationship between injury age and expressions of erythropoietin (EPO) and its receptor EPOR in the brain tissue of rats after cerebral injury.@*METHODS@#Seventy-two rats were randomly divided into control group (36 rats) and cerebral injury group (36 rats). The rats were sacrificed at 1, 2, 4, 8, 12, 24 h after cerebral injury (6 rats at each time point) and the brain tissues were extracted. The expressions of mRNA and protein of EPO and EPOR at different time points were detected by real-time fluorescent quantitative PCR and Western bloting.@*RESULTS@#The expressions of EPO and EPOR increased within 24 h after injury. The expressions of mRNA and protein of EPO were related to the injury age, and the correlations were 0.875, 0.911, respectively (P < 0.05). The expressions of mRNA and protein of EPOR were related to the injury age, and the correlation coefficients were 0.936, 0.905, respectively (P < 0.05).@*CONCLUSION@#The expressions of EPO and EPOR increase gradually in the early stage of the rat's cerebral injury, which are associated with the injury age and could be a useful value for estimating injury age.

Influence of GATA-1 on Expression of EpoR in Bone Marrow CD71+ Cells of Rat Model with High Altitude Polycythemia / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore the influence of GATA-1 on expression of EpoR in bone marrow CD71+ cells of rat model with high altitude polycythemia (HAPC).</p><p><b>METHODS</b>Forty-eight male SD rats were randomly divided into normal control and HAPC model group. HAPC model was established at the altitude of 4 300 meters in the natural environment, and verified by bone marrow cell counts and hematological parameters. Myeloid CD71+ cells were separated by the density gradient centrifugation combined with magnetic activated cell sorting. The expression of EpoR on cell membrane was detected by flow cytometry and cell immunofluorescence. The expression changes of GATA-1 and EpoR mRNA and protein were detected by Q-PCR and Western blot, respectively. CD71+ cells were cultured under normoxia and hypoxia, respectively. After transfection for 96 h, the optimal interference sequence GATA-1 shRNA1 was selected. And the mRNA and protein expression level of GATA-1 and EpoR were detected by Q-PCR and Western blot respectively.</p><p><b>RESULTS</b>The animal model with HAPC was established successfully and comfirmed by the bone marrow cell counting and the hematologic parameters in comparison with that of the normal control. EpoR expression on the myeloid CD71+ cell membrane in HAPC group was significantly higher than that in normal control (P<0.05). The expression of GATA-1 and EpoR in myeloid CD71+ cells of HAPC group was higher than that in control group (P<0.05). The mRNA and protein expression of GATA-1 and EpoR in two groups positively correlated (control group, r=0.929, P<0.01, r=0.802, P<0.05; HAPC group, r=0.822, P<0.05, r=0.839, P<0.01). However, the mRNA and protein expression of EpoR at normoxia and hypoxia was significantly lower than that in negative control group after interfernce with GATA-1 shRNA1 for 96 h (P<0.05). And the expression of GATA-1 and EpoR under hypoxia was higher than that in normoxia.</p><p><b>CONCLUSION</b>The effect of GATA-1 on EpoR expression may be correlated with the pathogenesis of HAPC.</p>

The role of cytokines in lymphoma with anemia / 中国实验血液学杂志

This study was purposed to investigate the role of cytokines in pathogenesis of lymphoma-associated anemia. The levels of IFN-γ, IL-1β, IL-6, TNF-α and EPO in serum from 45 lymphoma patients and 12 normal controls were detected by using ELISA, the EPOR level on bone marrow cells were detected by flow cytometry, the CFU-E of bone marrow cultured in vitro was counted under inverted microscope. The results showed that 25 (55.6%) out of 45 newly diagnosed lymphoma patients had anemia before diagnosis, 13 (28.9%) had anemia during therapy, 7 (15.5%)never had anemia. The IFN-γ and TNF-α levels in serum of patients with moderate and severe anemia were significantly higher than those in patients with mild anemia and without anemia as well as normal controls. The EPO, IL-6 and IFN-γ levels correlated negatively with Hb concentration in patients, the EPOR level in patients without anemia significantly higher than that in patients with anemia and normal controls. The bone marrow CFU-E amount in patients showed positive correlation with Hb and EPOR levels. It is concluded that the increased IFN-γ, TNF-α and IL-6 may contribute to the anemia in lymphoma, and yet the EPO and EPOR levels are elevated to balance negative regulatory effects on hematopoiesis and maintain normal hematopoiesis.

Leukocytoclastic Vasulitis Induced by Methoxy Polyethylene Glycol-Epoetin Beta / 대한피부과학회지

Methoxy polyethylene glycol-epoetin beta (Mircera(R), Roche), a third-generation erythropoiesis-stimulating agent (ESA) is known as a continuous erythropoietin receptor activator (CERA). In patients with anemia associated with chronic kidney disease (CKD), it is administered intravenously or subcutaneously. Treatment-related adverse events induced by methoxy polyethylene glycol-epoetin beta occurred in 6%. Hypertension, diarrhea and nasopharyngitis were the most commonly reported adverse events. Cutaneous adverse reactions are rarely experienced with methoxy polyethylene glycol-epoetin beta including maculopapular eruption, facial erythema, and tinea pedis. To the best of our knowledge, no cases of leukocytoclastic vasculitis associated with methoxy polyethylene glycol-epoetin beta have ever been published in medical literature. Herein, we report on a case of leukocytoclastic vasulitis induced by methoxy polyethylene glycol-epoetin beta in a patient with anemia associated with chronic kidney disease.

Expression of erythropoietin and erythropoietin receptor in non-small cell lung cancer and its correlation with microvessel density / 中华肿瘤杂志

<p><b>OBJECTIVE</b>Erythropoietin and erythropoietin receptor (EPO-R) are expressed in many kinds of tumors. The EPO/EPO-R signaling is involved in tumor cell proliferation, invasion and angiogenesis. The aim of this study was to detect the expression of EPO-R in non-small cell lung cancer (NSCLC), and explore its correlation with angiogenesis.</p><p><b>METHODS</b>The expression patterns of EPO and EPO-R in 31 cases of NSCLC tissues were detected by immunohistochemistry, and that in benign lung lesions of 21 patients as control. To analyze the correlation of EPO/EPO-R expression patterns and clinicopathological factors. CD34 was used to label the vascular endothelial cells and calculate the microvessel density (MVD).</p><p><b>RESULTS</b>The positive rates of EPO and EPO-R expression in NSCLC were 67.7% and 96.8%, respectively, significantly higher than those in the control ones. The positive rates of EPO and EPO-R expression in adjacent tissues were 19.4% and 35.5%, and in benign lesions were 9.5% and 19.0%, respectively (P < 0.001). The expression patterns of EPO/EPO-R were not related with pTNM stage, histological type, histological grade and lymph node metastasis (P > 0.05). Increased MVD was correlated with poor differentiation, lymph node metastasis, and advanced stage.</p><p><b>CONCLUSIONS</b>High expression of EPO/EPO-R in NSCLC patients suggest that they may be involved in tumorigenesis. EPO/EPO-R expression and MVD are closely related, and they might be an endogenous stimulant of angiogenesis during the progression of non-small cell lung cancer. It may provide evidence for clinical diagnosis.</p>

Early Sustained Injections of Erythropoietin Improve Angiogenesis and Restoration of Perfusion in the Ischemic Mouse Hindlimb

This study was conducted to investigate the effects of erythropoietin (Epo) on both acute and chronic limb ischemia (ALI and CLI) and to evaluate the differences in mechanisms according to the method of Epo administration. Hindlimb ischemia was made in BALB/c mice with femoral artery ligation. The mice were divided into four groups: Group 1 (control, no treatment), Group 2 (ALI, early multiple doses), Group 3 (ALI, early single high dose), Group 4 (CLI, late multiple doses). Blood flow ratio significantly increased in Group 2 in 4 weeks. Expression of pAkt and Erythropoietin receptor were significantly higher in Group 2 on postoperative day (POD) 7. The number of CD31- and vascular endothelial growth factor-positive cells were significantly higher in Group 2 on POD 7 and 56. Group 3 and 4 showed a tendency of higher cell counts than the control. The early sustained Epo was effective in improving blood flow through angiogenesis. In chronic phase, weekly multiple dosing of Epo induced angiogenesis, however, the blood flow ratio did not increase significantly. The results of this study suggest that Epo administration during the acute phase followed by maintenance for several days may be important for increasing blood flow and angiogenesis.

Expression of erythropoietin and its receptor increases in colonic neoplastic progression: The role of hypoxia in tumorigenesis.

Background: Tissue hypoxia is a characteristic patho-physiologic property of colorectal cancer. This process may also add to a therapeutic problem of solid tumor resistance to chemo- and radiation therapy. Erythropoietin (Epo) expression is induced by tissue hypoxia. Acting via its receptor (EpoR), Epo inhibits apoptosis of erythroid cells and has been shown to rescue neurons from hypoxic damage. Increased Epo and EpoR expression has been recently described in human breast, renal and cervical carcinoma. Given the characteristic tumor diathesis present in majority of colorectal cancers, we examined whether Epo signaling may play a role in colonic neoplastic progression. Materials and Methods: Expression of Epo and EpoR was examined using immunohistochemistry in 24 cases of primary colorectal and metastatic adenocarcinomas versus adenomas and normal colonic mucosa. Immunohistochemical stains were evaluated semiquantitatively based on a four-tiered scale. Based on the combination of extent and intensity of immunoreactivity, an immunostaining score (0-300) was determined for each sample. Expression of Epo and EpoR protein and mRNA was examined using Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR), respectively, in both normal colonic tissue and carcinoma specimens in five cases. Results: Epo expression was sequentially increased in normal colonic mucosa (8.3 ± 5.6, mean ± SEM), adenoma (26.4 ± 9.1), primary carcinoma (96.1 ± 12.8) and metastatic carcinoma (122 ± 51.3). EpoR expression was also sequentially increased in normal colonic mucosa (22.3 ± 11.8), adenoma (108.7 ± 24.2), primary carcinoma (178.7 ± 16.6) and metastatic carcinoma (220 ± 58.3) (P< 0.05 for all results). Epo and EpoR showed enhanced expression in the areas adjacent to ischemia/necrosis. Western blot and RT-PCR analysis revealed increased EpoR protein and mRNA levels in carcinoma compared to normal mucosal colon specimens. Focal stromal Epo and EpoR immunoreactivity was present in 10 and 12 cases, respectively. Conclusions: The uniform increase in the expression of Epo and EpoR along the colonic neoplastic sequence and further increase in ischemic/necrotic areas indicates that the Epo signaling pathway is an important component in colon carcinogenesis including possible epithelial-stromal interactions.

Synthesis and biological evaluation of 125I-erythropoietin as a potential radiopharmaceutical agent for tumours

Erythropoietin (EPO) is a glycoprotein hormone responsible for regulating erythropoiesis. Expression of EPO and EPO receptors (EPOr) has recently been demonstrated in some neoplastic cell lines and tumours, suggesting a potential new target for therapy. In this work, EPO was labeled with iodine-125 using the lactoperoxidase method, known to prevent damage to protein during radioiodination, and labeling conditions were optimized. In vitro stability studies have shown that 125I-EPO is radiochemically stable for 20 days after radiolabeling. In vitro cell binding studies have demonstrated very low binding (<2 percent) of EPO to normal and neoplastic cell lines tested. As expected, the biodistribution in healthy mice exhibited comparatively high rates of fixation in the organs of the excretory system. Thyroid also proved to be a critical organ which may indicate in vivo dissociation of 125I-EPO. In mice with induced melanoma, only a residual fixation in the tumour was evident. Further studies are warranted on other tumoral cell lines to better understand the binding process and internalization into cells. Studies on EPO labeled with carbon-11 could be valuable, since there is a greater chance of preserving the biological activity of the protein using this method.

A eritropoetina (EPO) é um hormônio glicoprotéico responsável pela regulação da eritropoese. Recentemente foi demonstrado que os receptores de EPO (EPOr) estão expressos em algumas linhas celulares neoplásicas, o que sugere a sua potencialidade como um novo alvo terapêutico. Neste trabalho a EPO foi radiomarcada com iodo-125 através do método da lactoperoxidase, menos agressivo para a viabilidade biológica das proteínas. A 125I-EPO revelou ser radioquimicamente estável durante 20 dias após a síntese. Um estudo biológico in vitro em linhas celulares tumorais demonstrou que a 125I-EPO apresenta uma ligação muito fraca (<2 por cento), tanto em células normais como nas linhagens tumorais testadas. A biodistribuição em camundongos saudáveis apresentou taxas de fixação relativamente maiores nos órgãos excretores e a tireóide revelou ser o órgão crítico, o que pode indicar a dissociação in vivo da 125I-EPO. No estudo em camundongos com melanoma induzido a fixação no tumor foi residual. Serão, no entanto, necessários novos estudos em outras linhagens tumorais para entender o seu processo de internalização e ligação nas células. Estudos da EPO radiomarcada com carbono-11 poderão também revelar-se interessantes, já que neste método há maior probabilidade da atividade biológica ser preservada.

Expression of erythropoietin and its receptor in the brain of newborn rats suffering from fetal distress / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the expression of erythropoietin (EPO) and its receptor (EPOR) in the brain of newborn rats suffering fetal distress.</p><p><b>METHODS</b>A model of fetal distress was prepared by ligating bilateral uterine arteries of the rats with full-term pregnancy for 10 minutes before cesarean sections. The expression levels of EPO and EPOR in the brain of newborn rats were detected by reverse transcription polymerase chain reaction (RT-PCR) and Western blot at 0, 2, 6, 12, 24, 48, 72 hrs and 7 days after birth. Serum EPO levels were measured using ELISA simultaneously. The newborn rats born by cesarean sections which were not subjected to uterine artery ligation were used as the control group.</p><p><b>RESULTS</b>The expression of EPO protein and mRNA in brain tissues in the fetal distress group increased significantly compared with the control group 2, 6 and 12 hrs after birth (P<0.05). The expression of EPOR protein and mRNA in brain tissues in the fetal distress group increased significantly compared with the control group 2, 6, 12, 24 and 48 hrs, and 3 days after birth (P<0.05). Serum EPO levels in the fetal distress group were significantly higher than in the control group 2 hrs after birth.</p><p><b>CONCLUSIONS</b>The EPO and EPOR levels in the brain increase quickly after birth in newborn rats suffering from fetal distress. The EPOR is high expressed for a longer time than EPO. This can provide a basis for the treatment of neonatal brain damage induced by fetal distress by exogenous EPO.</p>

Effects of hermap gene on p-STAT5 kinases in signal transduction pathway during erythroid differentiation / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the effects of hermap gene on kinases in erythroid signal transduction pathway and investigate the mechanism of hermap on erythroid differentiation.</p><p><b>METHODS</b>The K562 cells expressing hermap and hermap-siRNA respectively were established for up- and down-regulating the expression of hermap gene. These K562 cells were then induced by Ara-C to erythroid differentiation and analyzed at 0, 24, 48, 72 and 96 h, respectively, for cell morphology and biphenylamine staining positive cells, determination of CD235a, CD36, kinases p-STAT5, p-Akt, p-MAPK and p-c-JUN by FCM; and quantification of hermap gene and γ (Aγ,Gγ) globin gene by FQ-PCR.</p><p><b>RESULTS</b>With up-regulating hermap gene and inducing by Ara-C, K562 cells were changing to low ratio of nucleus to cytoplasm, cytoplasm colour from basophilic to pinkish or amethyst tinge, increase of number of biphenylamine positive cells and expression of CD235a, CD36, γ (Aγ,Gγ) globin gene, hermap gene and p-STAT5 from 0 to 96 h. At 0, 24, 48, 72 and 96 h of culture, the positive rates of p-STAT5 cells were detected of 0.46%, 4.54%, 20.01%, 23.65% and 33.08%, respectively. This results demonstrated that there was a positive correlation between expression of p-STAT5 and hermap gene expression (P < 0.05).</p><p><b>CONCLUSION</b>hermap gene can stimulate erythroid differentiation of Ara-C induced K562 cells mainly through JAK/STAT5 signal transduction pathway.</p>

EPOR and TPOR expressions on CD34+ CD59- and CD34+ CD59+ bone marrow cells from patients with paroxysmal nocturnal hemoglobinuria / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the expressions of erythropoietin receptor (EPOR) and thrombopoietin receptor (TPOR) on CD34+ CD59- and CD34+ CD59+ bone marrow (BM) cells from patients with paroxysmal nocturnal hemoglobinuria (PNH).</p><p><b>METHODS</b>(1) The expressions of EPOR and TPOR on CD34+ CD59- and CD34+ CD59- BM cells from 26 PNH patients and 16 normal controls were examined by flow cytometry (FCM). (2) The mRNA expression of the EPOR and the TPOR in BM mononuclear cells (BMMNC) from 25 PNH patients and 13 normal controls were examined by RT-PCR.</p><p><b>RESULTS</b>(1) The percentage of EPOR positive cells in PNH CD34+ CD59+ BMMNC [(30.67 +/- 18.30)%] was significantly higher than that in PNH CD34+ CD59- BMMNC [(8.05 +/- 3.51)%] (P < 0.01) and than that in control CD34+ CD59+ BMMNC [(8.24 +/- 6.51)%] (P < 0.01), but there was no obvious difference between the CD34+ CD59-BMMNC in PNH and CD34+ CD59+ BMMNC in control. (2) The percentage of TPOR positive cells in PNH CD34+ CD59+ BMMNC [(28.15 +/- 17.75)%] was significantly higher than that in PNH CD34+ CD59-BMMNC [(15.65 +/- 14.45)%] (P < 0.05) and than that in control CD34+ CD59+ BMMNC [(10.77 +/- .39)%] (P < 0.01), but there was no obvious difference between the CD34+ CD59- BMMNC in PNH and CD34+ CD59+ BMMNC in control. (3) There was no statistic difference in EPOR mRNA and TPOR mRNA expressions in BMMNCs between PNH patients group [(0.41 +/- 0.37) and (0.32 +/- 0.19), respectively] and control group [(0.47 +/- 0.33) and (0.40 +/- 0.29), respectively].</p><p><b>CONCLUSION</b>The expression of EPOR and TPOR of PNH patients on BM CD34+ CD59+ cells are significantly higher than those on BM CD34+ CD59- cells. The difference may be due to abnormal transcription of both receptor coding genes.</p>

Erythropoietin receptor positive circulating progenitor cells and endothelial progenitor cells in patients with different stages of diabetic retinopathy / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the possible involvement of erythr opoietin (EPO)/erythropoietin receptor (EPOR) system in neovascularization and vascular regeneration in diabetic retinopathy (DR).</p><p><b>METHODS</b>EPOR positive circulating progenitor cells (CPCs: CD34(+)) and endothelial progenitor cells (EPCs: CD34(+)KDR(+)) were assessed by flow cytometry in type 2 diabetic patients with different stages of DR. The cohort consisted of age- and sex-matched control patients with out diabetes ( n=7),non-proliferative DR (NPDR, n=7),non-proliferative DR (PDR, n=8), and PDR complicated with diabetic nephr opathy (PDR-DN, n=7).</p><p><b>RESULTS</b>The numbers of EPOR(+) CPCs and EPOR(+) EPCs were reduced remarkably in NPDR compared with the control group (both Pü0.01), whereas rebounded in PDR and PDR-DN groups in varyingdegrees. Similar changes were observed in respect of the proportion of EPOR(+)CPCs in CPCs (NPDR vs. control, Pü0.01) and that of EPOR(+) EPCs in EPCs (NPDR vs. control, Pü0.05).</p><p><b>CONCLUSION</b>Exogenous EPO, mediated via the EPO/EPOR system of EPCs, may alleviate the impaired vascular regeneration in NPDR, whereas it might aggravate retinal neovascularization in PDR due to a rebound of EPOR(+)EPCs associated with ischemia.</p>

Expression of EPOR on acute leukemia cells and its clinical significance / 中国实验血液学杂志

This study was aimed to explore the expression of erythropoietin receptor (EPOR) on acute leukemia cells and its clinical significance. Bone marrow of 40 patients with acute leukemia (AL) and 24 patients with normal bone marrow as control group were collected. Samples came from outpatients and inpatients in our hospital. EPOR mRNA was detected by reverse transcription-PCR. The results showed that there was EPOR expression on AL cells, the expression rate was 57.5%, and the average expression level (Gray value) was 0.3549 ± 0.2800, but both were lower than that in control group (p < 0.05). There was no significant statistic difference of expression rate between acute myelogenous leukemia (AML) and acute lymphoblastic leukemia (ALL) (p > 0.05), and expression level of AML EPOR was higher than that of ALL (p < 0.05). It is concluded that there is EPOR expression on AL cells, while the expression rate and expression level are lower than those in control group (p < 0.05). There is no significant statistic difference of the expression rate between AML and ALL (p > 0.05), and the expression level of AML EPOR is higher than that of ALL (p < 0.05).

Effects of hyperoxia on erythropoietin receptor expression in lung development of neonatal rats / 中华儿科杂志

<p><b>OBJECTIVE</b>Oxygen toxicity is thought to be a major contributing factor in the pathogenesis of bronchopulmonary dysplasia (BPD). Animal experiments reveal that erythropoietin (EPO) may have protective effects against hyperoxic lung injury, but the mechanisms remain unknown. The aim of this study was to evaluate effects of hyperoxia on erythropoietin receptor expression in lung development of neonatal rats.</p><p><b>METHODS</b>Several litters of Wistar pups were pooled together within 12 hours after birth and randomly divided into two groups (n = 24 in each): air-exposed control group and hyperoxia-exposed group. In hyperoxia-exposed group, the rats were exposed to 85% oxygen. Pups (n = 8) from each group were sacrificed on postnatal days 3, 7, and 14. The pulmonary histological and morphometric changes were observed after hematoxylin-eosin (HE) staining under light microscope. Radical alveolar counts (RAC) were compared between the two groups to evaluate the differences of alveolarization. Expressions of platelet endothelial cell adhesion molecule-1 (PECAM-1) and erythropoietin receptor (EPOR) in lung tissue were measured by immunohistochemistry. Expressions of EPOR mRNA and EPOR protein were measured by RT-PCR and Western blotting.</p><p><b>RESULTS</b>In hyperoxia-exposed group, there were a few inflammatory cells infiltration in interstitium on day 3 and inflammatory response worsened on day 7. Alveolar and capillary hypoplasia and interstitial fibrosis were evident on day 14. RAC increased in air-exposed control group along with the age in days. RAC decreased from day 7 in hyperoxia-exposed group compared with air-exposed control group [(6.85 ± 1.04) vs. (7.33 ± 1.0), P < 0.01], which was more evident on day 14 [(6.20 ± 1.58) vs. (9.07 ± 0.69), P < 0.001]. Expression of PECAM-1 protein increased in air-exposed control group along with the age in days. But in hyperoxia-exposed group, it decreased on day 7 and 14 [(15.14 ± 1.51) vs. (31.47 ± 2.43), (11.04 ± 1.76) vs. (41.41 ± 3.83), P < 0.001] compared with air-exposed control group. Expression of EPOR on day 3 in air-exposed control group was the strongest and weakened gradually with the increase of postnatal days. Expression of EPOR in hyperoxia-exposed group decreased on day 3 and became more evident on day 7 and day 14 compared with air-exposed control group [(1.62 ± 0.04) vs. (1.82 ± 0.06), P < 0.05; (0.48 ± 0.01) vs. (1.10 ± 0.07), (0.39 ± 0.04) vs. (0.87 ± 0.03), P < 0.001]. Expression of EPOR mRNA on day 3 in air-exposed control group was the strongest and was decreased significantly in hyperoxia-exposed group compared with air-exposed control group at all time points [(0.87 ± 0.07) vs. (1.1 ± 0.17), (0.18 ± 0.07) vs. (0.36 ± 0.08), P < 0.01;(0.14 ± 0.05) vs. (0.36 ± 0.09), P < 0.001].</p><p><b>CONCLUSIONS</b>EPOR may participate in the modulation of normal lung development. Depressed expression of EPOR and PECAM-1 may be involved in the pathogenesis of alveolar and capillary hypoplasia induced by hyperoxia.</p>

High glucose stimulates the expression of erythropoietin in rat glomerular epithelial cells / 한국실험동물학회지

It has been reported that the levels of erythropoietin are associated with diabetes mellitus. Glomerular epithelial cells, located in the renal cortex, play an important role in the regulation of kidney function and hyperglycemia-induced cell loss of glomerular epithelial cells is implicated in the onset of diabetic nephropathy. This study investigated the effect of high glucose on erythropoietin and erythropoietin receptor expression in rat glomerular epithelial cells. We found that 25 mM D-glucose, but not mannitol or L-glucose, stimulated erythropoietin mRNA and protein expression in a time dependent manner (>4 h) in rat glomerular epithelial cells. In addition, 25 mM glucose, but not mannitol or L-glucose, also increased the phosphorylation of erythropoietin receptor, suggesting a role for erythropoietin receptor phosphorylation in erythropoietin synthesis. We conclude that high glucose stimulates erythropoietin production and erythropoietin receptor phosphorylation in rat glomerular epithelial cells.