Erythropoietin Concentration Research Articles

Low doses of recombinant human erythropoietin does not affect C-terminal FGF23 in healthy men.

Recombinant human erythropoietin (rhEpo) can improve human performance, but misuse remains difficult to detect. C-terminal fibroblast growth factor 23 (cFGF23) was recently demonstrated to increase following injection of a single high dose rhEpo, but the effect of more frequent low doses is unknown. Using a randomized double-blind placebo-controlled design, we investigated whether 2 weeks of subcutaneous injections three times a week of 50 IU/kg Eprex (low-dose) or 20 IU/kg Eprex (micro-dose) increase cFGF23 levels compared with saline (placebo) injections in 24 healthy males. Venous blood was sampled at day -3, 0, 1, 3, 11, 14, 18, and 25 of the treatment and analyzed for cFGF23 and erythropoietin concentration ([EPO]). The level of cFGF23 was similar at days -3, 0, 1, 3, 11, 14, 18, and 25 with the low-dose (23 ± 4, 26 ± 5, 23 ± 7, 27 ± 6, 25 ± 8, 24 ± 10, 22 ± 5, and 24 ± 7 RU/mL, respectively), micro-dose (23 ± 6, 25 ± 5, 23 ± 8, 28 ± 9, 27 ± 7, 25 ± 9, 25 ± 5, and 23 ± 6 RU/mL, respectively) and placebo (23 ± 6, 24 ± 6, 26 ± 7, 26 ± 6, 31 ± 6, 31 ± 7, 24 ± 4, and 27 ± 8 RU/mL, respectively) treatment. The correlation coefficient between plasma [EPO] and plasma cFGF23 levels was R2 = 0.01 and insignificant. The results demonstrate that cFGF23 is not sensitive to low doses of subcutaneous rhEpo injections in healthy males.

Erythropoiesis and Red Cell Indices Undergo Adjustments during Pregnancy in Response to Maternal Body Size but not Inflammation.

During human pregnancy, iron requirements gradually increase, leading to higher amounts of erythropoietin (EPO) and reticulocytes, and changes in erythrocyte size and density. Women with pregestational obesity experience “obesity hypoferremia” during pregnancy, which alters iron homeostasis. In this study we aimed to describe the relationship between EPO and iron nutrition status during nonanemic pregnancy, and to explore whether obesity and inflammation influence erythropoiesis and red cell indices. We conducted a secondary analysis of a cohort followed throughout pregnancy. Participants were nonanemic women assigned to two study groups based on pregestational body mass index (pgBMI): adequate weight (AW, n = 53) or obesity (Ob, n = 40). All received a multivitamin supplement. At gestational ages (GA) 13, 21, 28 and 34, we measured hemoglobin and red cell indices with an ACT-5DIFF hematology counter, and reticulocyte percentage by manual cell counting. EPO, interleukin (IL–6) and markers of iron status, i.e., hepcidin, serum transferrin receptor (sTfr) and ferritin, were measured by ELISA. Bivariate correlations showed that EPO was positively associated with pgBMI, GA, sTfr and IL-6, but negatively associated with hepcidin, ferritin and hemoglobin, and unrelated to iron intake. Generalized linear models adjusted for confounding factors showed that EPO and erythrocyte concentrations were significantly higher in women in the Ob group, while mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and red cell distribution width (RDW) were lower; reticulocytes and mean corpuscular hemoglobin concentration (MCHC) were not different. Differences were not altered when controlling for inflammation (IL–6). These changes suggest that, in addition to altering iron metabolism, a larger maternal body size during pregnancy results in higher erythropoiesis without increasing hemoglobin, which is exhibited in the latter being distributed among more and smaller erythrocytes.

Chronic Exposure to Low-Dose Carbon Monoxide Alters Hemoglobin Mass and V˙O2max.

This study aimed to determine the effect of chronic low-dose CO application on hemoglobin mass (Hbmass) and V˙O2max. For 3 wk, 11 healthy and moderately trained male subjects inhaled a CO bolus five times per day to increase their HbCO concentration by ~5%. Another 11 subjects received a placebo. Hbmass, serum erythropoietin concentration, ferritin, and basic hematological parameters were determined before and weekly during and until 3 wk after the CO inhalation period. V˙O2max tests on a cycle ergometer were performed before and after the CO administration period. In the CO group, Hbmass increased from 919 ± 69 to 962 ± 78 g in week 3 (P < 0.001) and was maintained for the following 3 wk. Reticulocytes (%) and immature reticulocyte fraction significantly increased after 1 wk. Serum erythropoietin concentration tended to increase after 1 wk (P = 0.07) and was suppressed in the postperiod (P < 0.01). Ferritin decreased during the inhalation period (from 106 ± 37 to 72 ± 37 ng·mL, P < 0.001). V˙O2max tended to increase from 4230 ± 280 to 4350 ± 350 mL·min (P < 0.1) immediately after the inhalation period and showed a significant relationship to the change in Hbmass (y = 4.1x - 73.4, r = 0.70, P < 0.001). Chronic continuous exposure to low-dose CO enhances erythropoietic processes resulting in a 4.8% increase in Hbmass. The individual changes in Hbmass were correlated to the corresponding changes in V˙O2max. Examination of ethical and safety concerns is warranted before the implementation of low-dose CO inhalation in the clinical/athletic setting as a tool for modifying Hbmass.

Preeclampsia: The Interplay Between Oxygen-Sensitive miRNAs and Erythropoietin.

Changes in the oxygen partial pressure caused by a violation of uteroplacental perfusion are considered a powerful inducer of a cascade of reactions leading to the clinical manifestation of preeclampsia (PE). At the same time, the induction of oxygen-dependent molecule expression, in particular, miRNA and erythropoietin, is modulated. Therefore, the focus of our study was aimed at estimating the miRNA expression profile of placental tissue and blood plasma in pregnant women with preeclampsia using deep sequencing and quantitative RT-PCR, as well as determining the concentration of erythropoietin. The expression of miR-27b-3p, miR-92b-3p, miR-125b-5p, miR-181a-5p, and miR-186-5p, as regulated by hypoxia/reoxygenation, was significantly increased in blood plasma during early-onset preeclampsia. The possibility of detecting early PE according to the logistic regression model (miR-92b-3p, miR-125b-5p, and miR-181a-5p (AUC = 0.91)) was evaluated. Furthermore, the erythropoietin level, which is regulated by miR-125b-5p, was significantly increased. According to PANTHER14.1, the participation of these miRNAs in the regulation of pathways, such as the hypoxia’s response via HIF activation, oxidative stress response, angiogenesis, and the VEGF signaling pathway, were determined.

Failure to confirm a sodium-glucose cotransporter2 inhibitor-induced hematopoietic effect in non-diabetic rats with renal anemia.

Aims/IntroductionClinical studies have shown that treatment with inhibitors of sodium–glucose cotransporter 2 (SGLT2) significantly increases the hematocrit in patients with type 2 diabetes. To investigate whether SGLT2 inhibitors directly promote erythropoietin production independently on blood glucose reduction, the hematopoietic effect of the specific SGLT2 inhibitor, luseogliflozin, was examined in non‐diabetic rats with renal anemia.Materials and MethodsRenal anemia was induced by treatment with adenine (200 or 600 mg/kg/day, orally for 10 days) in non‐diabetic Wistar–Kyoto or Wistar rats, respectively. Luseogliflozin (10 mg/kg bodyweight) or vehicle (0.5% carboxymethyl cellulose) was then administered for 6 weeks. The hematocrit and the hemoglobin (Hb), blood urea nitrogen, plasma creatinine, and plasma erythropoietin levels were monitored.ResultsTreatment with adenine decreased the hematocrit and the Hb level, which were associated with increases in the blood urea nitrogen and plasma creatinine levels. In Wistar–Kyoto rats treated with 200 mg/kg/day adenine, administration of luseogliflozin induced glycosuria, but did not change the blood urea nitrogen, plasma creatinine levels, hematocrit, Hb or plasma erythropoietin levels. Similarly, luseogliflozin treatment failed to change the hematocrit or the Hb levels in Wistar rats with renal anemia induced by 600 mg/kg/day of adenine. Plasma erythropoietin concentrations were also not different between luseogliflozin‐ and vehicle‐treated rats. Similarly, in human erythropoietin‐producing cells derived from pluripotent stem cells, luseogliflozin treatment did not change the erythropoietin level in the medium.ConclusionsThese data suggest that SGLT2 inhibitor fails to exert hematopoietic effects in non‐diabetic conditions.

Regular cold water swimming during winter time affects resting hematological parameters and serum erythropoietin.

Recreational winter swimming in cold sea water evokes body responses to regularly repeated cold water immersion. However, the understanding of adaptive changes is still limited and data regarding very short-term exposure to severe cold stress are scarce. The purpose of the study was to examine the effects of regular active cold water exposure on resting blood elements and erythropoietin in male and female cold water swimmers (CWSs). Thirty four healthy subjects (18 men and 16 women) aged 50.0 ± 12.2 years were swimming in cold sea water during winter season at least twice a week. The average water temperature was 9.5°C in October, 1.0°C in January and 4.4°C at the end of April. Fasting blood samples were taken within the first weeks of October, January and April. Serum erythropoietin (EPO), complete blood count (CBC) including evaluation of: red blood cells (RBC count, hemoglobin, hematocrit and RBC indices), white blood cells (WBC count with WBC differential), platelets (PLT count), serum folate and serum immunoglobulins (IgG, IgA, IgM) were determined. Between October and April an increase was observed in the following parameters: RBC (from 4.8 x 1012/L to 5.2 x 1012/L, P < 0.001), hemoglobin (from 8.6 mmol/L to 9.4 mmol/L, P < 0.001), MCH (from 1.8 fmol to 1.9 fmol, P = 0.003), MCHC (from 19.9 mmol/L to 20.6 mmol/L, P < 0.001), EPO (from 6.3 IU/L to 8.1 IU/L, P = 0.001). At the same time decreased concentrations of PLT (from 249.9 x 109/L to 221.6 x 109/L, P = 0.005), folate (from 10.5 ng/mL to 7.4 ng/mL, P < 0.001) and immunoglobulins (IgG: from 11.8 g/L to 10.9 g/L, P < 0.001; IgA: from 2.5 g/L to 2.2 g/L, P < 0.001; IgM: from 0.9 g/L to 0.8 g/L, P < 0.001). Statistically significant changes in EPO and PLT values were noted only in female CWSs. We conclude that regular cold water swimming induces adaptive changes in the resting blood elements and EPO concentrations which are more evident in female organism.

Clinical outcomes of hepatitisC virus elimination using glecaprevir and pibrentasvir in hemodialysis patients: A multicenter study.

The incidence of hepatitisC virus (HCV) infection is much higher in hemodialysis patients than that in healthy individuals. The prognosis of hemodialysis patients with HCV infection is poorer than that without HCV infection. Therefore, antiviral intervention is pivotal for HCV infection in hemodialysis patients. Recent evaluations of the pangenotypic regimen of glecaprevir/pibrentasvir show that it is highly effective and safe for HCV-infected hemodialysis patients. However, a few reports showed that the effect of HCV elimination by glecaprevir/pibrentasvir improved liver dysfunction or anemia. The aim of the present study was to determine clinical outcomes after HCV elimination using the glecaprevir/pibrentasvir regimen in HCV-infected hemodialysis patients. This study was a retrospective, six-center study conducted in Japan, in which 24 hemodialysis patients with HCV genotype1-2 treated with glecaprevir/pibrentasvir were recruited. Blood examinations were performed at end of treatment (EOT), and at 3, 6, and 12months post-treatment during the 12-month follow-up period. The overall sustained virologic response rate was 100% (24/24). During the DAA treatment period, adverse events were observed in 20.8% of patients (5/24), and pruritus was the most frequently observed in 12.5% (3/24). Interestingly, we observed an improved control of anemia after EOT with a significant increase in hemoglobin levels. In addition, total bilirubin was diminished, and platelet counts and albumin, total cholesterol, and alpha-fetoprotein levels remained unchanged after EOT in hemodialysis patients. Furthermore, erythropoietin concentration was not increased after EOT. HCV elimination using glecaprevir/pibrentasvir treatment might be a major breakthrough for the control of anemia in hemodialysis patients.

Testosterone Administration During Energy Deficit Suppresses Hepcidin and Increases Iron Availability for Erythropoiesis

Severe energy deprivation markedly inhibits erythropoiesis by restricting iron availability for hemoglobin synthesis. The objective of this study was to determine whether testosterone supplementation during energy deficit increased indicators of iron turnover and attenuated the decline in erythropoiesis compared to placebo. This was a 3-phase, randomized, double-blind, placebo-controlled trial. The study was conducted at the Pennington Biomedical Research Center. Fifty healthy young males. Phase 1 was a 14-day free-living eucaloric controlled-feeding phase; phase 2 was a 28-day inpatient phase where participants were randomized to 200 mg testosterone enanthate/week or an isovolumetric placebo/week during an energy deficit of 55% of total daily energy expenditure; phase 3 was a 14-day free-living, ad libitum recovery period. Indices of erythropoiesis, iron status, and hepcidin and erythroferrone were determined. Hepcidin declined by 41%, indicators of iron turnover increased, and functional iron stores were reduced with testosterone administration during energy deficit compared to placebo. Testosterone administration during energy deficit increased circulating concentrations of erythropoietin and maintained erythropoiesis, as indicated by an attenuation in the decline in hemoglobin and hematocrit with placebo. Erythroferrone did not differ between groups, suggesting that the reduction in hepcidin with testosterone occurs through an erythroferrone-independent mechanism. These findings indicate that testosterone suppresses hepcidin, through either direct or indirect mechanisms, to increase iron turnover and maintain erythropoiesis during severe energy deficit. This trial was registered at www.clinicaltrials.gov as #NCT02734238.

Роль тканевого эритропоэтина и механизмов обратной связи в локальной регуляции эритропоэза

Erythroblastic islets (EI) of rat bone marrow were cultured for 24, 48, or 72 h together with various erythrocytes, simulating the state of erythron hyper- or hyporegeneration in the in vitro system. The concentration of erythropoietin was determined in the control and experimental cultures of EI by two-site enzyme-linked immunosorbent assay. With the addition of reticulocytes/young red blood cells (erythron hyperregeneration model) at a dose of 30 or 60 cells / 1 EI, after 24 h of cultivation, the concentration of erythropoietin in the culture medium increased by 37% compared to control cultures. In cultures with 120/1 EI reticulocytes / young red blood cells, the concentration of erythropoietin decreased by 25% by 48 h. The addition of mature/old red blood cells (an erythron hyporegeneration model) caused inhibition of erythropoietin synthesis in EI culture. By 48 h, the content of this hormone in the cultivation medium significantly decreased in all series of the experiment: in cultures with 30 cells / 1 EI - by 18%, and in cultures with a large erythrocyte load - by 28%. In 72-h cultures containing 30, 60, or 120 red blood cells / 1 EI, the concentration of erythropoietin decreased by 26%, 40%, and 53%, respectively, compared with the control. We found that local regulation of erythropoiesis is directly related to the synthesis of erythropoietin in EI and depends on the number and maturity of cells produced by red bone marrow. The data obtained suggest that it is tissue erythropoietin that is the most important link in the implementation of feedback mechanisms that provide an adequate response of the erythron to an oxygen demand in physiological conditions and support erythropoiesis in pathological conditions accompanied by small production of erythropoietin in the kidneys.

Адаптация к интервальной гипоксии: динамика насыщения крови кислородом и некоторых гематологических показателей

Adaptation to hypoxia is an important object of medical research. The aim of this study was to investigate the dynamics of blood oxygen saturation (SpO2), arterial blood pressure (BP), red blood cells, reticulocytes, hemoglobin and erythropoietin (EPO) concentrations during intermittent hypoxic training (IHT). The study was conducted in 11 healthy male volunteers; 2 regimens were tested: 11 and 14 days of IHT at FIO2 = 9%. Exposure to the hypoxic gas mixture caused a reduction in SpO2 by an average of 20.4% (p &lt; 0.05), a 22% increase in the heart rate (p &lt; 0.05) and a 4.5% decrease in diastolic BP (p &lt; 0.05) relative to the initial levels. After 11 days of IHT training, the reticulocyte count was increased by 16.6% (p &lt; 0.05), and there was a distinct tendency to elevated red blood cells (p &gt; 0.05) and hemoglobin (p &gt; 0.05). EPO concentrations declined by 44.2% (p &lt; 0.05) relative to the initial level. Extending the regimen to 14 days resulted in a 3.9% increase in red blood cell count (p &lt; 0.05) and a 4.7% elevation of hemoglobin concentrations (p &lt; 0.05), accompanied by the recovery of the initial reticulocyte count. The applied 2-week IHT regimen resulted in the increased red blood cell count and elevated hemoglobin, suggesting an improvement in the oxygen-carrying capacity of the blood. The proposed regimen can be used to improve physical performance of individuals working in extreme environmental conditions.

Toxic effect of copper-zinc pyrite ore on erythropoiesis in chronic experiment

Natural ores contain a large number of harmful components for human health. Workers of mining and processing enterprises, who have long-term contact with these natural elements, are often diagnosed with anemia, that pathogenesis is not sufficiently studied. Aim of the study was to detail the mechanisms of rats’ erythron disorders in the long-termintoxication by natural complex of heavy metal compounds of copper-zinc pyrite ore. Material and methods. The work was performed on 60 white non-linear male rats aged 3-4 months weighing 220,52 ± 15,51 g. The experimental group of animals (n = 40) were injected orally with water suspension of copper-zinc powder in a bread crumb an hour before standard feeding during 75-120 days. The blood and bone marrow of experimental groups of rats were carried out on the 75-th, 90-th, 105-th and 120-th days of the experiment. The blood and bone marrow of rats’ control groups were studied on the 75-th and 105-th day. The central part of erythron was assessed by the number and composition of the erythroblastic islets (EI) of bone marrow, the number of free macrophages, the coefficients of involvement of colonyforming units of red blood cells (CFU-E) and macrophages into erythropoiesis. Results . In the peripheral blood of experimental rats the number of red blood cells and the content of hemoglobin were reliably less than the control values on the 90-th and 120-th day, the number of reticulocytes was exceeded the control group on the 75-th, 105-th and 120-th day. In the bone marrow of experimental rats there were only a single EI1 and EI2 classes of maturity. Throughout the experiment, the content of free macrophages and EI with reticulocytes «crown» in the bone marrow of rats was elevated, and the concentration of iron and erythropoietin in the blood, on the contrary, was reduced. The intensity of CFU-E involvement in the erythropoiesis was less than the control level by 2 times on 105th and 120th days of the experiment. Conclusion . With long-term introduction of copper-zinc pyrite ore in the bone marrow of rats the process of formation of EI de novo is suppressed by destabilizing the contact of free bone macrophages with young red blood cells. There is reduces in the content of serum erythropoietin and bound iron, that combines with the change of erythropoiesis nature, leads to decreasing of the number of mature red blood cells and content of hemoglobin in the peripheral blood.

Leucopenia, Neutropenia, Lymphopenia and Monocytopenia in a 15 year Old Girl with Iron Deficiency Anemia Responding to Iron Therapy: A Case Report

Despite the high prevalence of iron deficiency anemia (IDA) in children, extensive information about its impact on growth and cognitive functions, less is known about how it affects the non-erythrocytes cell lines and its implications. High erythropoietin levels in severe iron deficiency anemia may down regulate the production of non- erythroid precursors resulting in various cytopenia, however, the mechanism of this is not fully understood. Reports depicting the association of iron deficiency anemia with cytopenia is quite scarce in pediatric population. We report a case of a 15 year old girl presented with severe iron deficiency anemia and leucopenia, lymphopenia, neutropenia and monocytopenia who has no other evidence of bone marrow dysfunction. The patient responded to iron therapy with prompt reversal of all cell counts. It is therefore recommended to include iron study and plasma erythropoietin concentration in the evaluation of otherwise healthy children presenting with cytopenia. Likewise, to consider iron deficiency in the causative list of non-erythroid cytopenia such as neutropenia.

Regulation of muscle and metabolic physiology by hypothalamic erythropoietin independently of its peripheral action

ObjectiveThe glycoprotein hormone erythropoietin (EPO) is required for erythropoiesis, and the kidney is the primary site of adult EPO synthesis. Limited evidence has suggested that EPO could be detectable in the brain under certain conditions, but it remains unknown if the brain might have its own EPO system for biological functions that are independent of peripheral EPO production and action. We performed this study to address this question using mice under normal conditions versus pathophysiological conditions including aging and dietary obesity. MethodsEPO expression was measured in different brain regions as well as in the cerebrospinal fluid. Hypothalamic ventricular EPO was administered to physiologically examine possible therapeutic effects on the conditions of aging and dietary obesity. Body weight, body composition, insulin tolerance, and glucose tolerance were measured to assess the central effects of EPO on metabolic physiology, and muscle strength and histology were analyzed to assess the central effects of EPO on muscle function. In addition, β2-adrenergic receptor knockout bone marrow transplant was employed to determine the potential role of bone marrow in linking the brain to some of these peripheral functions. ResultsThis study revealed that EPO is expressed in the ventromedial hypothalamus in addition to a few other brain regions and is present in the cerebrospinal fluid. Unlike blood EPO concentration, which increased with aging and dietary obesity, hypothalamic EPO decreased in these disease conditions. Therapeutically, aged mice were chronically treated with EPO in the hypothalamic ventricle, showing an increase in lean mass, while body weight and fat mass decreased as a result of a moderate reduction of food intake. Both muscle and metabolic functions were improved by this central treatment, and mechanistically, adrenergic signals to the bone marrow played a role in conveying hypothalamic EPO to these peripheral actions. Dietary obesity was also studied, showing that hypothalamic EPO treatment caused a reduction in food intake and obesity, leading to improved metabolic functions related to decreased fat as well as increased lean mass. ConclusionsHypothalamic EPO plays a role in the central regulation of muscle and metabolic physiology, while its decline contributes to aging and obesity physiology in a manner that is independent of peripheral EPO.

Angiogenic and inflammatory biomarker levels in aqueous humor and vitreous of neovascular glaucoma and proliferative diabetic retinopathy.

To explore the relationships between the aqueous and vitreous levels of vascular endothelial growth factor-A (VEGF-A), interleukin-8 (IL-8), placental growth factor (PlGF) and erythropoietin (EPO) in proliferative diabetic retinopathy (PDR) and neovascular glaucoma (NVG). Aqueous and vitreous samples were obtained from patients with PDR and NVG during surgery. Aqueous and vitreous concentrations of VEGF-A, IL-8, PlGF and EPO were measured via enzyme-linked immunosorbent assay. No correlation between the aqueous and vitreous levels of VEGF-A, IL-8, PlGF or EPO was found in both the PDR and the NVG eyes. Aqueous VEGF-A was significantly higher in the NVG group (317.55 ± 36.25pg/ml, n = 15) than that in the PDR group (256.23 ± 46.11pg/ml, n = 17, P < 0.001). The level of VEGF-A in aqueous (317.55 ± 36.25pg/ml, n = 15) was significantly higher than that in vitreous (224.74 ± 60.32pg/ml, n = 15, P < 0.001) in NVG patients. The level of IL-8 in aqueous (76.55 ± 10.88pg/ml, n = 17) was significantly higher than that in vitreous (63.55 ± 10.74pg/ml, n = 17, P = 0.001) in PDR patients. The level of EPO in aqueous (18.62 ± 2.87mIU/ml, n = 15) was significantly higher than that in vitreous (15.97 ± 3.11mIU/ml, n = 15, P = 0.022) in NVG patients. The ratio of aqueous versus vitreous for VEGF-A was significantly higher in the NVG group (1.475 ± 0.289, n = 15) than that in the PDR group (0.996 ± 0.227, n = 17, P < 0.001). Aqueous levels of VEGF-A, IL-8, PlGF and EPO do not correlate with vitreous levels of those proteins. The relationship between protein levels in aqueous humor and vitreous might be dependent on different disease status or protein types investigated.

Canagliflozin Improves Erythropoiesis in Diabetes Patients with Anemia of Chronic Kidney Disease.

Background: We evaluated the erythropoietic effects of canagliflozin, a sodium-glucose cotransporter 2 inhibitor, in type 2 diabetes patients with anemia of chronic kidney disease.Methods: Nine diabetes patients were enrolled and administered 100 mg canagliflozin once a day for 12 weeks. The patients received fixed doses of conventional antidiabetic drugs and renin-angiotensin system inhibitors for 8 weeks before enrollment; these drugs were continued during the study. Endpoints were changes in erythropoiesis parameters, including erythrocyte and reticulocyte count, hemoglobin, hematocrit, and serum erythropoietin (EPO) concentration from baseline to 12 weeks. All variables were measured every 2 weeks.Results: Serum EPO concentration increased by 38 [15–62]% (P = 0.043) between baseline and 2 and 4 weeks. Reticulocyte count transiently increased at 2 weeks. Erythropoiesis occurred after 2 weeks of canagliflozin treatment. Erythrocyte count (from 386 ± 36 × 104/μL to 421 ± 36 × 104/μL; P = 0.0009), hemoglobin (from 11.8 ± 0.6 g/dL to 12.9 ± 1.1 g/dL; P = 0.0049), and hematocrit (from 37.1 ± 2.3% to 40.4 ± 3.2%; P = 0.002) increased from baseline to study completion. Although there were no significant changes in transferrin saturation, serum ferritin levels were decreased (P = 0.003).Conclusions: Canagliflozin treatment led to an improvement in erythropoiesis in patients with impaired kidney function. The effect on erythropoiesis appeared to be due to an EPO production-mediated mechanism and might be independent of glycemic control; however, further studies are needed to clarify this since the present study had a small sample size and no comparator group.

Altered Hemorheology in Fontan Patients in Normoxia and After Acute Hypoxic Exercise

BackgroundThe Fontan circulation is a unique palliation procedure for several congenital heart defects. Impaired exercise capacity has previously been demonstrated in these patients and also a higher risk for cardiopulmonary mortality. Hemorheology was shown to affect cardiopulmonary capacity and in turn to be affected by regular exercise and hypoxia but none of these have been investigated in Fontan patients so far. The aim of this study was to detect general differences in hemorheology in normoxia as well as possible altered hemorheological responses to hypoxia exposure and hypoxic exercise between Fontan patients and healthy controls.Methods and Findings26 Fontan patients and 20 healthy controls performed an acute exercise test (AET) on a bicycle ergometer under hypoxia with ambient 15.2% oxygen saturation (sO2). Blood samples were taken at rest in normoxia (T0), at rest in hypoxia (T1), after maximum exhaustion in hypoxia (T2), and after 50 min recovery in normoxia (T3). Hemorheological and blood parameters were investigated. Additionally, arterial stiffness was tested at T0. Red blood cell (RBC) deformability, NOx, erythropoietin (EPO) concentration, RBC count, hemoglobin (Hb) concentration and hematocrit (hct) were significantly increased in Fontan patients compared to controls. Same was observed for arterial stiffness. No changes were observed for RBC aggregation, fibrinogen concentration, free radical levels and vascular endothelial growth factor (VEGF). Hypoxia exposure did not change parameters, whereas exercise in hypoxia increased aggregation and hct significantly in both groups. Fontan patients showed significantly increased aggregation-disaggregation balance compared to controls.ConclusionAcute hypoxia exposure and exercise under hypoxia might have similar impact on hemorheology in Fontan patients and controls and was clinically well tolerated. Nevertheless, exercise alters aggregation and possibly hemodynamics which requires special attention in Fontan patients.

The Haematological Effects of Oleanolic Acid in Streptozotocin-Induced Diabetic Rats: Effects on Selected Markers.

Background Sustained hyperglycaemia leads to the development of haematological alterations which, if left untreated, is associated with cardiovascular complications. Insulin is the mainstay drug in type 1 diabetes mellitus (T1D); however, the use of insulin is associated with haematological alterations that could further worsen cardiovascular complications. Therefore, the aim of the study was to investigate the haematological effects of oleanolic acid (OA) in streptozotocin- (STZ-) induced diabetic rats. Methods The animals were separated into five groups; the nondiabetic group (ND), the diabetic control group (DC), and the treatment groups of insulin (170 μg/kg, s.c), metformin (500 mg/kg, p.o), and OA (80 mg/kg, p.o). OA was administered orally twice a day. Thereafter, the animals were sacrificed, and blood and tissues were collected for haematological, hormonal, and oxidative status analysis. Results Untreated diabetic rats exhibited hyperglycaemia, elevated glycated haemoglobin (HbA1c), oxidative stress, and a reduced erythropoietin (EPO) concentration when compared to ND rats. However, administration of OA attenuated hyperglycaemia, HbA1c, and EPO concentrations compared to DC rats. The reduction of blood glucose concentration, HbA1c, and improved EPO concentrations was further associated with a notable increase in red blood cell (RBC) count and other RBC indices. We also observed an increase in the antioxidant status of the RBCs with a concomitant decrease in oxidative stress. Conclusion These findings suggest that OA improves diabetes-induced haematological changes caused by hyperglycaemia and attenuates the progression of cardiovascular complications in DM individuals.

Serum erythropoietin concentration and its correlation with stage of diabetic retinopathy

BackgroundErythropoietin (EPO) is one of the systemic angiogenic factors, and its role in ocular angiogenesis and in diabetic retinopathy (DR) is not yet fully understood. The latest research data reveal a possible correlation of higher erythropoietin concentrations in the blood and in the eye with the development of more advanced stages of DR.The main aim of this work was to examine the possible influence of serum concentrations of erythropoietin on the development of diabetic retinopathy in patients with diabetes mellitus type 2.MethodsThe research involved 90 patients examined at the University Eye Clinic of the Clinical Center of Vojvodina, Novi Sad, Serbia. The first group comprised 60 patients with diabetes mellitus lasting for 10 years or more, with diabetic retinopathy. The second, control group consisted of 30 healthy individuals. In the first group of 60 patients with diabetes, 30 of them had non-proliferative diabetic retinopathy (NPDR), and 30 had proliferative diabetic retinopathy (PDR). Laboratory EPO serum levels were determined, and they were correlated to the stage of DR. Concentration of EPO was assessed by ELISA method.ResultsThe highest average concentration of EPO in serum (9.95 mIU/ml) was determined in the group of people with diabetes with PDR. The lowest average concentration of EPO in the serum (6.90 mIU/ml) was found in the control group. The average concentration of EPO in serum in the group of patients with diabetes with NPDR was 7.00 mIU/ml. The EPO concentration in serum was elevated in the group of PDR, and it was directly proportional to the level of the clinical stadium of PDR, being significantly higher in the moderate and severe subgroup of PDR comparing to the control healthy subjects, NPDR and mild PDR (p = 0.007).ConclusionsSignificantly elevated serum concentration of EPO in the advanced stages of DR, and positive correlation between EPO serum concentration and clinical stages of PDR, suggest that erythropoietin represents an important growth factor from blood, which plays a significant role in retinal ischemia and angiogenesis in diabetic retinopathy, especially in the proliferative stage of this disease.

Correlations of the severity of diabetic retinopathy with EPO, Caspase-3 expression and oxidative stress.

To investigate the relationships of the severity of diabetic retinopathy with erythropoietin (EPO), Caspase-3 expression, and oxidative stress. A total of 20 patients with non-proliferative diabetic retinopathy hospitalized from January 2017 to January 2018 were enrolled as observation group 1, 20 patients with proliferative diabetic retinopathy were chosen as observation group 2, and 20 patients with idiopathic macular hole were selected as control group. After admission, patients received all necessary examinations and underwent vitrectomy during which vitreous and retinal tissues were taken, and venous blood was collected. Then, the content of EPO, Caspase-3, nitric oxide (NO), and malondialdehyde (MDA) was detected through enzyme-linked immunosorbent assay (ELISA), the messenger ribonucleic acid (mRNA) levels of EPO, Caspase-3, NO, and MDA were measured via quantitative Polymerase Chain Reaction (qPCR), and the severity of diabetic retinopathy was evaluated by diabetic retinopathy grading score. Observation group 1 and 2 had significantly decreased the content of EPO (p<0.05) and overtly increased Caspase-3, NO, and MDA content (p<0.05) in comparison with control group. Compared with those in observation group 1, the EPO content was clearly lowered in observation group 2 (p<0.05), and the content of Caspase-3, NO, and MDA was evidently elevated (p<0.05). The diabetic retinopathy grading score was remarkably lower in control group than that in both observation group 1 and observation group 2 (p p<0.05), and it was significantly enhanced in observation group 2 compared with that in observation group 1 (p<0.05). Correlation analysis showed that the EPO content was negatively correlated with the severity of diabetic retinopathy, while the content of Caspase-3, NO, and MDA was positively related to the severity of diabetic retinopathy. The severity of diabetic retinopathy has a negative association with EPO and positive correlations with Caspase-3, NO, and MDA content.

TP0463518, a Novel Prolyl Hydroxylase Inhibitor, Specifically Induces Erythropoietin Production in the Liver.

Prolyl hydroxylase (PHD) 1/2/3 pan inhibitors are known to potentially induce erythropoietin (EPO) production in both the kidney and liver. The 2-[[1-[[6-(4-chlorophenoxy)pyridin-3-yl]methyl]-4-hydroxy-6-oxo-2,3-dihydropyridine-5-carbonyl]amino]acetic acid (TP0463518) is a novel PHD 1/2/3 pan inhibitor; however, the main source of EPO production after TP0463518 administration remained to be investigated. We examined the effect of TP0463518 in inducing EPO production in the kidney and liver by measuring the hypoxia-inducible factor 2α (HIF-2α), EPO mRNA, and serum EPO levels in normal and bilaterally nephrectomized rats. Furthermore, we examined whether liver-derived EPO improved anemia in 5/6 nephrectomized (5/6 Nx) rats. TP0463518 scarcely increased the HIF-2α and EPO mRNA expression levels in the kidney cortex, whereas oral administration of TP0463518 at 40 mg/kg dramatically increased the HIF-2α level from 0.27 to 1.53 fmol/mg and the EPO mRNA expression level by 1300-fold in the livers of healthy rats. After administration of TP0463518 at 20 mg/kg, the total EPO mRNA expression level in the whole liver was 22-fold that in the whole kidney. In bilaterally nephrectomized rats, TP0463518 raised the serum EPO concentration from 0 to 180 pg/ml at 20 mg/kg. Furthermore, repeated administration of TP0463518 at 10 mg/kg increased the reticulocyte count in 5/6 Nx rats on day 7 and raised the hemoglobin level on day 14. The present study revealed that TP0463518 specifically induced EPO production in the liver and improved anemia. The characteristic feature of TP0463518 would lead to not only a more detailed understanding of the PHD-HIF2α-EPO pathway in erythropoiesis, but a new therapeutic alternative for renal anemia. SIGNIFICANCE STATEMENT: Prolyl hydroxylase (PHD) 1/2/3 pan inhibitors are known to potentially induce erythropoietin (EPO) production in both the kidney and liver; however, their effects on renal EPO production have been shown to vary depending on the experimental conditions. The authors found that 2-[[1-[[6-(4-chlorophenoxy)pyridin-3-yl]methyl]-4-hydroxy-6-oxo-2,3-dihydropyridine-5-carbonyl]amino]acetic acid (TP0463518), a PHD 1/2/3 pan inhibitor, specifically induced EPO production in the liver and that the liver-derived EPO was pharmacologically effective. Investigation of the effects of TP0463518 may pave the way for the development of a new therapeutic alternative for renal anemia patients.