Mitochondrial metabolism is crucial for providing energy and heme precursors during erythroid development. Oxoglutarate dehydrogenase complex (OGDC) is a key enzyme in the mitochondrial tricarboxylic acid (TCA) cycle, and its level gradually increases during erythroid development, indicating its significant role in erythroid development. The aim of the present study was to explore the role and mechanism of OGDC in erythroid development. In this study, we treated erythroid progenitor cells with CPI-613, a novel lipoic acid analog that competitively inhibits OGDC. The results showed that CPI-613 inhibited erythropoietin (EPO)-induced differentiation and enucleation of human CD34⁺ hematopoietic stem cells into erythroid cells, suppressed cell proliferation, and induced apoptosis. The results of in vivo experiments showed that CPI-613 also hindered the recovery of mice from acute hemolytic anemia. Further mechanism research results showed that CPI-613 increased reactive oxygen species (ROS) in erythroid progenitor cells, inhibited mitochondrial respiration, caused mitochondrial damage, and suppressed heme synthesis, thereby inhibiting erythroid differentiation. Clinical research results showed that oxoglutarate dehydrogenase (OGDH) protein expression levels were up-regulated in bone marrow cells of polycythemia vera (PV) patients. Treatment with CPI-613 significantly inhibited the excessive proliferation and differentiation of erythroid progenitor cells of the PV patients. These findings demonstrates the critical role of OGDC in normal erythroid development, suggesting that inhibiting its activity could be a novel therapeutic strategy for treating PV.
Animals ; Humans ; Mitochondria/metabolism* ; Mice ; Ketoglutarate Dehydrogenase Complex/physiology* ; Cell Differentiation/drug effects* ; Cells, Cultured ; Erythropoiesis/drug effects* ; Reactive Oxygen Species/metabolism* ; Cell Proliferation/drug effects* ; Erythroid Precursor Cells/cytology* ; Apoptosis/drug effects* ; Thioctic Acid/pharmacology* ; Caprylates ; Sulfides

Transcription factor PU.1, as a core member of the ETS family, plays a pivotal role in the multi-lineage differentiation of hematopoietic stem cells, particularly in the regulation of erythroid differentiation. PU.1 orchestrates the process of hematopoietic stem cell differentiation towards erythroid cells by modulating the transcription of lineage-determining factors and interacting with other key transcription factors in a fine-tuned manner. PU.1 plays an irreplaceable role in the development and function of red blood cells, with its abnormal expression closely related to the occurrence and progression of various blood diseases, including leukemia, myelodysplastic syndromes, and various types of anemia. This article comprehensively analyzes the functional roles and molecular mechanisms of PU.1 in various stages of erythroid differentiation, as well as its potential roles in related blood diseases. This review not only deepens our understanding of the mechanism by which PU.1 regulates erythroid differentiation, but also provides theoretical grounds for blood disease therapies based on PU.1.
Humans ; Proto-Oncogene Proteins/genetics* ; Trans-Activators/genetics* ; Cell Differentiation/physiology* ; Hematologic Diseases/physiopathology* ; Erythroid Cells/cytology* ; Animals ; Erythropoiesis/physiology*

Objective: To reveal the compensatory features of bone marrow (BM) erythropoiesis in hereditary spherocytosis (HS) and to explore the effect of diferent hemoglobin levels on this compensation. Methods: Clinical and laboratory data of patients with HS were collected, and the peripheral blood absolute reticulocytes counts value was taken as the surrogate parameter to evaluate the ability of erythropoiesis compensation. BM erythropoiesis compensation in HS with diferent degrees of anemia were evaluated. Results: ①Three hundred and two patients were enrolled, including 115 with compensated hemolytic disease, 74 with mild anemia, 90 with moderate anemia, and 23 with severe anemia. ②Hemoglobin (HGB) was negatively correlated with serum erythropoietin in the decompensated hemolytic anemia group (EPO; rs=-0.585, P<0.001) . ③The median absolute reticulocyte count (ARC) of HS patients was 0.34 (0.27, 0.44) ×10(12)/L, up to 4.25 times that of normal people. The maximum ARC was 0.81×10(12)/L, about 10 times that of normal people. The median ARC of patients with compensated hemolytic disease was 0.29 (0.22, 0.38) ×10(12)/L, up to 3.63 times that of normal people. The median ARC of patients with hemolytic anemia was 0.38 (0.30, 0.46) ×10(12)/L, which was significantly higher than the patients with compensated hemolytic disease, up to 4.75 times that of normal people (z=4.999, P=0.003) . ④ ARC was negatively correlated with HGB in the compensated hemolytic disease group (rs=-0.177, P=0.002) and positively correlated with HGB in the decompensated hemolytic anemia group (rs=0.191, P=0.009) . There was no significant difference in the ARC among patients with mild, moderate, and severe anemia (χ(2)=4.588, P=0.101) . ⑤The median immature reticulocyte production index of the mild, moderate, and severe anemia groups was 13.1% (9.1%, 18.4%) , 17.0% (13.4%, 20.8%) , and 17.8% (14.6%, 21.8%) , respectively; the mild anemia group had lower index values than the moderate and severe anemia groups (P(adj) values were both<0.05) , but there was no significant difference between the latter groups (P(adj)=1.000) . The median immature reticulocyte count of patients in the mild, moderate, and severe groups was 5.09 (2.60, 7.74) ×10(10)/L, 6.24 (4.34, 8.83) ×10(10)/L, and 7.00 (3.07, 8.22) ×10(10)/L, respectively; there was no significant difference among the groups (χ(2)=3.081, P=0.214) . Conclusion: HGB can be maintained at a normal level through bone marrow erythropoiesis, while red blood cells are reduced in HS. However, once anemia develops, the bone marrow exerts its maximum erythropoiesis capacity and does not increase, regardless of anemia aggravation or serum EPO increase.
Bone Marrow ; Erythropoiesis ; Humans ; Reticulocyte Count ; Reticulocytes ; Spherocytosis, Hereditary

Hypoxia inducible factor (HIF)-stabilizers are being developed for the renal anemia treatment. This small molecules inhibit prolyl hydroxylase domain (PHD)-containing enzymes, causing HIF activation instead of degradation under the state of normoxia, finally increase production of intrinsic erythropoiesis. Current treatment guidelines suggest that renal anemia should be treated mainly with iron and erythropoiesis stimulating agents (ESAs). But there are several complications and concerns such as hypertension, ESA refractory anemia and increased cardiovascular mortality in using ESAs. Advantages of HIF stabilizers over ESAs are orally available, no dose-up requirement for inflammation. So far new HIF stabilizers showed efficacy and safety in renal anemia treatment. This new therapeutic agent may emerge as a standard treatment option for renal anmia treatment.
Anemia ; Anemia, Refractory ; Anoxia ; Erythropoiesis ; Hematinics ; Hepcidins ; Humans ; Hypertension ; Inflammation ; Iron ; Mortality ; Prolyl Hydroxylases ; Renal Insufficiency, Chronic

Objective: To understand the effect of sirolimus on the erythropoiesis of K562 cell line and bone marrow cells from pure red cell aplasia (PRCA) patients and normal controls. Methods: Different concentrations (10, 100, 1 000 nmol/L) of sirolimus were added to the K562 cell line or bone marrow cells from PRCA patients or normal controls and cultured 14 days for BFU-E formation. Meanwhile, sirolimus was also added to the serum treated PRCA bone marrow cells to cultivate for the same priod of time. Results: Neither K562 cells, bone marrow cells from PRCA patients or normal controls showed any difference when sirolimus was added to the culture system for BFU-E. However, BFU-E formation decreased after serum was added in PRCA patients (76.40±22.48 vs 136.33±12.58, t=-4.329, P=0.001) and this suppression of BFU-E was partly corrected by 1 000 nmol/L sirolimus treatment (97.14±15.83 vs 76.40±22.48, P=0.038). Conclusions: Sirolimus may modulate the suppression of erythropoiesis by serum instead of directly stimulate the growth of red blood cells in PRCA patients.
Erythroid Precursor Cells ; Erythropoiesis ; Humans ; K562 Cells ; Red-Cell Aplasia, Pure ; Sirolimus

The volume of hip arthroplasty is stiffly increasing because of excellent clinical outcomes, however it has not been shown to decrease the incidence of transfusions due to bleeding related to this surgery. This is an important consideration since there are concerns about the side effects and social costs of transfusions. First, anemia should be assessed at least 30 days before elective hip arthroplasty, and if the subject is diagnosed as having anemia, an additional examination of the cause of the anemia should be carried and steps taken to address the anemia. Available iron treatments for anemia take 7 to 10 days to facilitate erythropoiesis, and preoperative iron supplementation, either oral or intravenous, is recommended. When using oral supplements for iron storage, administer elemental iron 100 mg daily for 2 to 6 weeks before surgery, and calculate the dose using intravenous supplement. Tranexamic acid (TXA) is a synthetic derivative of the lysine component, which reduces blood loss by inhibiting fibrinolysis and clot degradation. TXA is known to be an effective agent for reducing postoperative bleeding and reducing the need for transfusions in primary and revision total hip arthroplasties. Patient blood management has improved the clinical outcome after hip arthroplasty through the introduction and research of various agents, thereby reducing the need for allogeneic blood transfusions and reducing the risk of transfusion-related infections and the duration of hospitalizations.
Anemia ; Arthroplasty* ; Blood Transfusion ; Consensus* ; Erythropoiesis ; Fibrinolysis ; Hemorrhage ; Hip* ; Hospitalization ; Humans ; Incidence ; Iron ; Lysine ; Tranexamic Acid

The production of red blood cells, termed erythropoiesis, occurs in two waves in the developing mouse embryo: first primitive erythropoiesis followed by definitive erythropoiesis. In the mouse embryo, both primitive and definitive erythropoiesis originates in the extra-embryonic yolk sac. The definitive wave then migrates to the fetal liver, fetal spleen and fetal bone marrow as these organs form. The fetal liver serves as the major organ for hematopoietic cell expansion and erythroid maturation after mid-gestation. The erythropoietic niche, which expresses critical cytokines such as stem cell factor (SCF), thrombopoietin (TPO) and the insulin-like growth factors IGF1 and IGF2, supports hematopoietic expansion in the fetal liver. Previously, our group demonstrated that DLK1⁺ hepatoblasts support fetal liver hematopoiesis through erythropoietin and SCF release as well as extracellular matrix deposition. Loss of DLK1⁺ hepatoblasts in Map2k4(−/−) mouse embryos resulted in decreased numbers of hematopoietic cells in fetal liver. Genes encoding proteinases and peptidases were found to be highly expressed in DLK1⁺ hepatoblasts. Capitalizing on this knowledge, and working on the assumption that these proteinases and peptidases are generating small, potentially biologically active peptides, we assessed a range of peptides for their ability to support erythropoiesis in vitro. We identified KS-13 (PCT/JP2010/067011) as an erythropoietic peptide-a peptide which enhances the production of red blood cells from progenitor cells. Here, we discuss the elements regulating embryonic erythropoiesis with special attention to niche cells, and demonstrate how this knowledge can be applied in the identification of niche-derived peptides with potential therapeutic capability.
Animals ; Bone Marrow ; Cytokines ; Embryonic Structures ; Erythrocytes ; Erythropoiesis ; Erythropoietin ; Extracellular Matrix ; Hematopoiesis ; In Vitro Techniques ; Liver ; Mice ; Peptide Hydrolases ; Peptides ; Somatomedins ; Spleen ; Stem Cell Factor ; Stem Cells ; Thrombopoietin ; Yolk Sac

Anemia, complicating the course of chronic kidney disease, is a significant parameter, whether interpreted as subjective impairment or an objective prognostic marker. Renal anemia is predominantly due to relative erythropoietin (EPO) deficiency. EPO inhibits apoptosis of erythrocyte precursors. Studies using EPO substitution have shown that increasing hemoglobin (Hb) levels up to 10–11 g/dL is associated with clinical improvement. However, it has not been unequivocally proven that further intensification of erythropoiesis stimulating agent (ESA) therapy actually leads to a comprehensive benefit for the patient, especially as ESAs are potentially associated with increased cerebro-cardiovascular events. Recently, new developments offer interesting options not only via stimulating erythropoeisis but also by employing additional mechanisms. The inhibition of activin, a member of the transforming growth factor superfamily, has the potential to correct anemia by stimulating liberation of mature erythrocyte forms and also to mitigate disturbed mineral and bone metabolism as well. Hypoxia-inducible factor prolyl hydroxylase inhibitors also show pleiotropic effects, which are at the focus of present research and have the potential of reducing mortality. However, conventional ESAs offer an extensive body of safety evidence, against which the newer substances should be measured. Carbamylated EPO is devoid of Hb augmenting effects whilst exerting promising tissue protective properties. Additionally, the role of hepcidin antagonists is discussed. An innovative new hemodialysis blood tube system, reducing blood contact with air, conveys a totally different and innocuous option to improve renal anemia by reducing mechanical hemolysis.
Activins ; Anemia* ; Apoptosis ; Erythrocytes ; Erythropoiesis* ; Erythropoietin ; Hematinics* ; Hemolysis ; Hepcidins ; Humans ; Metabolism ; Miners ; Mortality ; Prolyl-Hydroxylase Inhibitors ; Renal Dialysis ; Renal Insufficiency, Chronic ; Transforming Growth Factors

BACKGROUND: Engineered blood has the greatest potential to combat a predicted future shortfall in the US blood supply for transfusion treatments. Engineered blood produced from hematopoietic stem cell (HSC) derived red blood cells in a laboratory is possible, but critical barriers exist to the production of clinically relevant quantities of red blood cells required to create a unit of blood. Erythroblasts have a finite expansion capacity and there are many negative regulatory mechanisms that inhibit in vitro erythropoiesis. In order to overcome these barriers and enable mass production, the expansion capacity of erythroblasts in culture will need to be exponentially improved over the current state of art. This work focused on the hypothesis that genetic engineering of HSC derived erythroblasts can overcome these obstacles. OBJECTIVES: The objective of this research effort was to improve in vitro erythropoiesis efficiency from human adult stem cell derived erythroblasts utilizing genetic engineering. The ultimate goal is to enable the mass production of engineered blood. METHODS: HSCs were isolated from blood samples and cultured in a liquid media containing growth factors. Cells were transfected using a Piggybac plasmid transposon. RESULTS: Cells transfected with SPI-1 continued to proliferate in a liquid culture media. Fluorescence-activated cell sorting (FACS) analysis on culture day 45 revealed a single population of CD71+CD117+ proerythroblast cells. The results of this study suggest that genetically modified erythroblasts could be immortalized in vitro by way of a system modeling murine erythroleukemia. CONCLUSION: Genetic modification can increase erythroblast expansion capacity and potentially enable mass production of red blood cells.
Adult Stem Cells ; Culture Media ; Erythroblasts ; Erythrocytes ; Erythropoiesis* ; Flow Cytometry ; Genetic Engineering ; Hematopoietic Stem Cells ; Humans ; Intercellular Signaling Peptides and Proteins ; Leukemia, Erythroblastic, Acute ; Plasmids

Patients with hemolytic-uremic syndrome (HUS) can rapidly develop profound anemia as the disease progresses, as a consequence of red blood cell (RBC) hemolysis and inadequate erythropoietin synthesis. Therefore, RBC transfusion should be considered in HUS patients with severe anemia to avoid cardiac or pulmonary complications. Most patients who are Jehovah's Witnesses refuse blood transfusion, even in the face of life-threatening medical conditions due to their religious convictions. These patients require management alternatives to blood transfusions. Erythropoietin is a glycopeptide that enhances endogenous erythropoiesis in the bone marrow. With the availability of recombinant human erythropoietin (rHuEPO), several authors have reported its successful use in patients refusing blood transfusion. However, the optimal dose and duration of treatment with rHuEPO are not established. We report a case of a 2-year-old boy with diarrhea-associated HUS whose family members are Jehovah's Witnesses. He had severe anemia with acute kidney injury. His lowest hemoglobin level was 3.6 g/dL, but his parents refused treatment with packed RBC transfusion due to their religious beliefs. Therefore, we treated him with high-dose rHuEPO (300 IU/kg/day) as well as folic acid, vitamin B12, and intravenous iron. The hemoglobin level increased steadily to 7.4 g/dL after 10 days of treatment and his renal function improved without any complications. To our knowledge, this is the first case of successful rHuEPO treatment in a Jehovah's Witness child with severe anemia due to HUS.
Acute Kidney Injury ; Anemia* ; Blood Transfusion ; Bone Marrow ; Child* ; Child, Preschool ; Erythrocytes ; Erythropoiesis ; Erythropoietin* ; Folic Acid ; Hemolysis ; Hemolytic-Uremic Syndrome* ; Humans* ; Iron ; Jehovah's Witnesses ; Male ; Parents ; Religion ; Vitamin B 12