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.
Bone Marrow ; Erythropoietin ; Gene Expression ; Humans ; Leukemia, Myeloid, Acute ; Receptors, Erythropoietin

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.
Blotting, Western ; Erythropoietin ; Gene Silencing ; Humans ; Proteins ; genetics ; Receptors, Erythropoietin ; THP-1 Cells

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.
Animals ; Diabetes Mellitus ; Diabetic Nephropathies ; Epithelial Cells ; Erythropoietin ; Glucose ; Kidney ; Mannitol ; Phosphorylation ; Rats ; Receptors, Erythropoietin ; RNA, Messenger

Chronic hypoxia has been associated with change in neurovascular behavior, mediated, in part, by erythropoietin (EPO). EPO, a hematopoietic growth factor, could act as a neurotrophic factor. In the present study, we investigated the characteristics of EPO and erythropoietin receptor (EPOR) expressions by cortical neuron in vivo and in vitro and tested the hypothesis that EPO serves protective functions under chronic hypoxia. E18, P5 and P7 mice for 3 days and primary cultured neurons for 6 days were incubated in hypoxic conditions consisted of a mixture of 10% O2, 5% CO2, 85% N2. To study expressions of EPO, EPOR, caspases, pAKT, pERK, and PARP, immunohistochemical stainning and western blotting were carried out. In addition to expressing EPO and EPOR under normoxic conditions, neurons increased their expression of EPO and EPOR under hypoxia. The effects of recombinant EPO appeared to be mediated via the phosphatidylinositol (PI) 3- kinase-AKT pathway, correlated directly with activation of caspase 3. Also recombinant EPO decreased expression of caspase 8, but not caspase 9. Finally, recombinant EPO decreased apoptosis of cultured neurons as evaluated by expression of PARP. These data support a role for EPO in maintenance of cortical neuron under chronic hypoxia.
Animals ; Anoxia* ; Apoptosis ; Blotting, Western ; Caspase 3 ; Caspase 8 ; Caspase 9 ; Caspases ; Erythropoietin ; Mice ; Neurons* ; Phosphatidylinositols ; Receptors, Erythropoietin

BACKGROUND AND OBJECTIVES: Erythropoietin (EPO) is produced in the kidney and locally in the CNS and acts through binding to erythropoietin receptor (EPO-R). Apart from playing an essential role in erythropoiesis, recent research has shown that EPO has neurotrophic and neuroprotective functions in the CNS and found EPO and EPO-R in the inner ear. The aim of this study is to investigate distribution and expression of EPO and EPO-R in the inner ear after noise exposure. MATERIALS AND METHOD: Normal guinea pigs were exposed to noise. Ten of them were sacrificed at 1 hour of the noise exposure (group B) and another 10 animals were sacrificed at day 7 (group C). Four were normal controls that were not exposed to noise (Group A). Auditory function was evaluated by ABR for 7 days. Noise-induced morphological changes of cochlea were studied by phalloidin stain. The expression of EPO and EPO-R was examined by immunofluorescence. RESULTS: The hearing threshold shift reached a level of 40 dB SPL at 8 kHz at day 1 after noise exposure and underwent a partial recovery at day 7. Increased expression of EPO and EPO-R were observed at the level of spiral ganglion cells in the noise-exposed animals. CONCLUSION: It is suggested that noise exposure affects the distribution and expression of EPO and EPO-R in the inner ear.
Animals ; Cochlea ; Ear, Inner ; Erythropoiesis ; Erythropoietin ; Guinea ; Guinea Pigs ; Hearing ; Kidney ; Noise ; Phalloidine ; Receptors, Erythropoietin ; Spiral Ganglion

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.
Animals ; Brain/metabolism* ; Brain Injuries/pathology* ; Erythropoietin/metabolism* ; RNA, Messenger/metabolism* ; Random Allocation ; Rats ; Receptors, Erythropoietin/metabolism* ; Time Factors

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).
Case-Control Studies ; Humans ; Leukemia, Myeloid, Acute ; genetics ; metabolism ; RNA, Messenger ; genetics ; Receptors, Erythropoietin ; genetics ; metabolism

OBJECTIVEFunctionally, erythropoietin (EPO) can promote the proliferation and growth of erythroid progenitor cells, and it is widely used in the treatment of anemia in chronic diseases caused by tumor and inflammation. However, it is unclear whether EPO has any effect on tumor cell iron metabolism and tumor cell proliferation. The purpose of this study was to explore the effects of recombinant human EPO (rhEPO) on the expression of transferrin receptor (TfR, CD(71) antigen) of leukemic cell K562 and its relation to cell cycle.

METHODSIn vitro culture of K562 cell was performed with additions of various concentrations of rhEPO and Fe. Treatments were terminated at 24 h and 72 h, respectively. Then each group of cells was incubated with FITC-IgG antibody to CD(71) or PI, a kind of DNA dye. And TfR expression and DNA synthesis status were analyzed by flow-cytometry.

RESULTS(1) The expression of TfR by K562 cells increased significantly when incubated for 72 h with different concentrations of rhEPO. The measurement values of 5 U/ml, 10 U/ml and 20 U/ml groups were 12.2 +/- 1.40, 10.7 +/- 0.99 and 11.1 +/- 0.90, respectively. They were markedly increased when compared with that of control group (6.27 +/- 0.11, P < 0.05). (2) When incubated with rhEPO (5 u/ml) alone or combined with FeCl(3) (100 micro mol/L), the percentages of cells in S phase were 51.1% and 59.6%, respectively. They significantly increased when compared with that of control group (42.9%, P < 0.05).

CONCLUSIONSIron is very important for the proliferation of both normal cells and leukemic cells. It is essential to the activity of ribonucleotide reductase (RR). The authors hypothesized that rhEPO would increase the expression of TfR and intracellular iron content of leukemic cells, which would enhance the DNA synthesis and cell proliferation. Therefore, the clinical application of rhEPO to promote erythropoiesis of cancer patients should be cautious.

Cell Cycle ; drug effects ; Erythropoietin ; pharmacology ; Flow Cytometry ; Humans ; K562 Cells ; Receptors, Transferrin ; metabolism ; Recombinant Proteins

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.
Humans ; Receptors, Erythropoietin ; Acute Kidney Injury ; Apoptosis ; Inflammation ; Phagocytosis ; Reperfusion Injury

OBJECTIVETo investigate the possible involvement of erythr opoietin (EPO)/erythropoietin receptor (EPOR) system in neovascularization and vascular regeneration in diabetic retinopathy (DR).

METHODSEPOR 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).

RESULTSThe 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).

CONCLUSIONExogenous 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.

Aged ; Cell Count ; Diabetes Mellitus, Type 2 ; complications ; Diabetic Retinopathy ; pathology ; Endothelium, Vascular ; cytology ; Erythropoietin ; blood ; Female ; Humans ; Male ; Middle Aged ; Receptors, Erythropoietin ; analysis ; Stem Cells ; physiology