Increased Erythropoietin Production Research Articles

Nucleated Red Blood Cell Counts Differentiate Cardiac from Respiratory Causes of Cyanosis at Birth.

Tissue hypoxia increases erythropoietin production and release of immature erythrocytes that can be measured using nucleated red blood cell counts (nRBC). We hypothesized that hypoxia due to congenital heart disease (CHD) is chronic and is better tolerated than hypoxia due to respiratory disease (RD), which is an acute stress in newborns leading to higher nRBC. This study assesses the utility of nRBC as a marker to differentiate hypoxia due to CHD vs RD in term neonates. This was a single-center, retrospective study of term neonates with cyanosis from 2015 to 2022. Neonates < 37weeks of gestation, with hypoxic-ischemic encephalopathy, and those with other causes of cyanosis were excluded. The patients were divided into 2 groups: cyanotic CHD and cyanotic RD. Clinical and laboratory data done within 12h and 24-36h after birth were collected. Data are represented as median and Interquartile range. Of 189 patients with cyanosis, 80 had CHD and 109 had RD. The absolute nRBC count at ≤ 12h of age was lower in the CHD (360 cells/mm3) compared to RD group (2340 cells/mm3) despite the CHD group having significantly lower baseline saturations. A value of 1070 cells/mm3 was highly sensitive and specific for differentiating CHD from RD. The positive predictive value for this cut-off value of 1070 cells/mm3 was 0.94 and the negative predictive value was 0.89. The absolute nRBC is a simple screening test and is available worldwide. A nRBC < 1070 cells/mm3 in cyanotic newborns should hasten the search for CHD etiology with the possible need for prostaglandin therapy.

Effect of long-term treatment with trivalent chromium on erythropoietin production in HepG2 cells

Trivalent chromium (Cr(III)) is sometimes taken as a long-term supplement, but its effectiveness is unclear. Recently, Cr(III) reportedly modulates peroxisome proliferator-activated receptor gamma (PPARγ) expression. Our previous study reported that increased PPARγ after 24 h Cr(III) treatment promoted erythropoietin (EPO) production in HepG2 cells. In the current study, we analyzed 4-week Cr(III) treatment effects on PPARγ and EPO production in HepG2 cells. Long-term Cr(III) treatment resulted in significantly elevated mRNA expression levels of PPARγ and EPO compared to controls. Additionally, treatment with a PPARγ inhibitor suppressed EPO mRNA expression. Increased EPO mRNA expression due to stimulation with hypoxia or cobalt was unaffected by long-term Cr(III) treatment. Administration of lipopolysaccharide and pyocyanin which causes oxidative stress, promoted EPO production, but this effect was attenuated in cells treated with Cr(III). Long-term Cr(III) treatment increased hypoxia inducible factor (HIF)-1α and 2α mRNA expression and protein levels. Increased PPARγ, induced by long-term Cr(III) treatment, suppressed sirtuin1 (SIRT1) mRNA expression and increased EPO mRNA expression, suggesting that increased PPARγ attenuated the suppressive effect of SIRT1 on HIF. These results suggest that the sustained increase in PPARγ during long-term Cr(III) treatment maintains increased EPO production through a mechanism different from that observed under hypoxia.

Mechanisms of enhanced renal and hepatic erythropoietin synthesis by sodium-glucose cotransporter 2 inhibitors.

Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce the risk of major heart failure events, an action that is statistically linked to enhanced erythropoiesis, suggesting that stimulation of erythropoietin and cardioprotection are related to a shared mechanism. Four hypotheses have been proposed to explain how these drugs increase erythropoietin production: (i) renal cortical reoxygenation with rejuvenation of erythropoietin-producing cells; (ii) counterregulatory distal sodium reabsorption leading to increased tubular workload and oxygen consumption, and thus, to localized hypoxia; (iii) increased iron mobilization as a stimulus of hypoxia-inducible factor-2α (HIF-2α)-mediated erythropoietin synthesis; and (iv) direct HIF-2α activation and enhanced erythropoietin gene transcription due to increased sirtuin-1 (SIRT1) signaling. The first two hypotheses assume that the source of increased erythropoietin is the interstitial fibroblast-like cells in the deep renal cortex. However, SGLT2 inhibitors do not alter regional tissue oxygen tension in the non-diabetic kidney, and renal erythropoietin synthesis is markedly impaired in patients with anemia due to chronic kidney disease, and yet, SGLT2 inhibitors produce an unattenuated erythrocytic response in these patients. This observation raises the possibility that the liver contributes to the production of erythropoietin during SGLT2 inhibition. Hypoxia-inducible factor-2α and erythropoietin are coexpressed not only in the kidney but also in hepatocytes; the liver is a major site of production when erythropoietin stimulation is maintained for prolonged periods. The ability of SGLT2 inhibitors to improve iron mobilization by derepressing hepcidin and ferritin would be expected to increase cytosolic ferrous iron, which might stimulate HIF-2α expression in both the kidney and liver through the action of iron regulatory protein 1. Alternatively, the established ability of SGLT2 inhibitors to enhance SIRT1 might be the mechanism of enhanced erythropoietin production with these drugs. In hepatic cell lines, SIRT1 can directly activate HIF-2α by deacetylation, and additionally, through an effect of SIRT in the liver, peroxisome proliferator-activated receptor-γ coactivator-1α binds to hepatic nuclear factor 4 to promote transcription of the erythropoietin gene and synthesis of erythropoietin. Since SIRT1 up-regulation exerts direct cytoprotective effects on the heart and stimulates erythropoietin, it is well-positioned to represent the shared mechanism that links erythropoiesis to cardioprotection during SGLT2 inhibition.

Effect of pentavalent inorganic arsenic salt on erythropoietin production and autophagy induction

Arsenic is abundant in the environment and takes the form of trivalent and pentavalent arsenic compounds. Arsenite has been reported to both promote and suppress erythropoietin (EPO) production and autophagy induction. EPO production is involved in hematopoiesis, and autophagy induction is involved in cytoprotection, both of which are thought to be cellular responses to arsenic stress. While there are reports that show the effects of EPO on autophagy induction, the relationship between EPO production and autophagy induction is unclear. Therefore, this study analyzed the effect of the pentavalent inorganic arsenic salt arsenate on EPO production in vitro and in vivo and EPO-induced autophagy in HepG2 cells. Exposure of HepG2 cells to low-concentration arsenate was observed to increase EPO production and induced autophagy. Moreover, a ROS scavenger suppressed the arsenate-induced increase in autophagy and EPO mRNA levels. Both EPO production and autophagy induction contributed to protection from arsenate-induced cytotoxic stress. HepG2 cells expressed the EPO receptor and production of EPO by HepG2 cells acted in an autoregulatory manner to suppress autophagy induction. In vivo administration of low-concentration arsenate to rats increased EPO mRNA levels in the liver and kidney. These results suggested that low-concentration arsenate promotes EPO production and autophagy induction in HepG2 cells, and the resultant EPO production contributes to cytoprotection of cultured cells via EPO receptor activation.

GAMBARAN HEMOGLOBIN IBU HAMIL DI UPTD PUSKESMAS III DINAS KESEHATANKECAMATAN DENPASAR UTARA TAHUN 2022

Background: Hemoglobin deficiency in pregnant women is one of the health issues that can occur during the pregnancy. Anemia is more common in pregnant women because they require more oxygen, which causes an increase in erythropoietin production. The risk of anemia is connected to hemoglobin levels in pregnant women, with hemoglobin levels of less than 11 g/dl being classified low. Premature labor, miscarriage, extended labor, uterine atony, hemorrhage, and shock are all risks of anemia during pregnancy. Methods: The study used a descriptive design with a sample population of 34 pregnant women. Results: Hemoglobin levels in 22 pregnant women (64.7%) were relatively low, with the majority of them coming onto an age category of not at risk 18 people (81.8%), second trimester age 9 pregnant women (40.9%), pregnancy distance 13 pregnant women (59.1%), and parity 16 pregnant women (72.7%). Conclusion: The majority of pregnant women at UPTD PUSKESMAS III North Denpasar District Health Office have low hemoglobin levels.

POLYCYTHEMIAWITH HYDRONEPHROSIS:A RARE CASE

Secondary polycythaemia results from increased Erythropoietin production which acts on normal erythropoietic progenitors leading to erythrocytosis. This report is about a 64 years old hypertensive and anaemic male who presented with complaints of painful per rectal bleeding with dribbling micturition. On undergoing relevant investigations, he was found to be anaemic with low haemoglobin and haematocrit. Lateron, subsequent follow up visits he was incidentally detected to be polycythemic. On further investigations for the same, he got diagnosed with urinary bladder outlet obstruction, atonic bladder with ureteric narrowing and left hydronephrosis with elevated erythropoietin levels. On treatment, his Haemoglobin count, haematocrit and Erythropoietin levels came back to normal.Unexplained polycythaemia should be thoroughly investigated to rule out renal pathology.

New principles for the treatment of chronic heart failure: the phenomenon of sodium-glucose cotransporter type 2 inhibitors

Chronic heart failure (CHF) is one of the most important problems in clinical cardiology due to high morbidity, frequent hospitalizations and poor prognosis of patients. Quite unexpectedly, sodium-glucose cotransporter type 2 (SGLT2i) inhibitors dapagliflozin and empagliflozin, which were created for the treatment of diabetes mellitus, proved to be effective means of reducing the risk of an adverse outcome in patients with CHF, they were included in a new four-component therapy for CHF with a reduced left ventricular ejection fraction with a class of recommendations I and level of evidence A. The basis for changing the clinical guidelines for CHF was the results of large randomized trials of DAPA-HF and EMPEROR-Reduced. Despite the obvious clinical benefit of using SGLT2i in CHF, the mechanisms of the observed effects remain speculative and continue to be actively studied. In particular, the literature discusses the role of osmotic diuresis, lowering blood pressure and body weight, increasing erythropoietin production, influencing myocardial remodeling, modifying the energy metabolism of the heart, inhibiting the sodium-hydrogen exchanger, autophagy, and influencing leptin and adiponectin levels. SGLT2i has many of the qualities of an ideal agent for the treatment of CHF with reduced left ventricular ejection fraction, including a single dose without the need for titration, once daily administration, early positive effects on clinical outcomes and quality of life, a favorable safety and tolerability profile with a frequency of serious side effects not different from placebo. At the same time, the choice of medical tactics may be influenced by the features of the evidence base of SGLT2i, in particular, the reduction in cardiovascular mortality and death from any cause in a randomized trial of dapagliflozin.

HPT‐ Axis Activation During Cold Head Out Water Immersion is Not Modified by Moderate Hypoxia

PurposeThe Bajau, an indigenous population renowned for breath‐hold diving, have comparatively large spleen volumes. This adaptation is purportedly indicative of a greater capacity to store red blood cells, which may aid operations in the aquatic environment. Spleen size in the Bajau is associated with the PDE10A genotype that encodes an enzyme that catalyzes the release of thyroxine (T4) from the thyroid gland. T4 is readily released during cold stress as the terminus to activation of the hypothalamus‐pituitary‐thyroid (HPT) ‐axis to increase metabolic rate. T4, and downstream counterpart triiodothyronine (T3), can also stimulate erythropoiesis by increasing erythropoietin production, which can be further promoted with hypoxia. Thus, exposure to cold water may augment erythropoiesis as hypoxia develops during breath‐hold diving via activation of the HPT‐axis. However, interactions between cold exposure and hypoxia on HPT‐axis activation have not been directly explored. Mountaineering expedition studies indirectly suggest that T4 release is elevated by hypoxia. Thus, this study tested the hypothesis that during cold head out water immersion (HOWI) acute hypoxia augments circulating thyroid hormone concentrations compared to normoxia.MethodsIn a randomized crossover single blind design, 12 healthy adults (27 ± 2 y, 2 women) completed one hour of cold (22.0 ± 0.1⁰C) HOWI breathing either normobaric normoxia (FiO2 = 0.21 ± 00, NORM) or normobaric hypoxia (FiO2 = 0.13 ± 00, HYP). Free (f) and total (t) T3 and T4, and thyroid stimulating hormone (TSH) were measured in venous blood samples obtained before (baseline), during (15‐, 30‐, and 60‐min), and 15 min following immersion (post‐). Arterial oxyhemoglobin saturation (SpO2) and rectal temperature were measured continuously. Data are presented as mean ± SD.ResultsSpO2 was lower in HYP (90 ± 3%) compared to NORM (98 ± 1%, p &lt;.001). Rectal temperature did not differ between HYP and NORM (p &gt; .711) but decreased over time in both trials (HYP ‐ baseline: 37.2 ± 0.4⁰C, post‐: 36.4 ± 0.5⁰C, p&lt;.001, NORM ‐ baseline: 37.2 ± 0.4⁰C, post‐: 36.3 ± 0.5⁰C, p &lt;.001). From baseline to post‐HOWI, fT3 (HYP: +0.3 ± 0.4 pg/mL, NORM: +0.4 ± 0.6 pg/mL, p &lt;.001), fT4 (HYP: +1.6 ± 1.7 pg/mL, NORM: +0.7 ± 1.3 pg/mL, p &lt;.001), tT3 (HYP: +0.3 ± 0.5 ng/mL, NORM: +0.2 ± 0.4 ng/mL, p= .053), and tT4 (HYP: +0.6 ± 0.4 µg%, NORM: +0.4 ± 0.5 µg%, p &lt; .001) increased, but the magnitude did not differ between inspirates (p &gt; .165). Relative to baseline, tT4 at 15 min (HYP: ‐0.2 ± 0.3 µg%, NORM: ‐0.3 ± 0.3 µg%, p = .025), and TSH at 30 min (HYP: ‐0.2 ± 0.2 µIU/mL, NORM: ‐0.2 ± 0.3 µIU/mL, p = .029) and 60 min (HYP: ‐0.2 ± 0.2 µIU/mL, NORM: ‐0.3 ± 0.4 µIU/mL, p = .008) of HOWI were lower, but did not differ between inspirates (p = .921).ConclusionsIncreases in circulating thyroid hormone concentrations during one hour of cold HOWI are not modified by normobaric hypoxia. Thus, moderate hypoxia does not likely affect activation of the HPT‐axis during short duration cold exposure. Further investigation is warranted to determine the possibility of circulating thyroid hormones to augment the erythropoietic response to acute hypoxia during cold exposure.

POS-486 SECONDARY POLYCYTHEMIA IN NEPHROTIC SYNDROME – AN UNCOMMON ASSOCIATION

Polycythaemia is defined as haemoglobin (Hb) of over16.5 g/dL in men and 16 g/dL in women or haematocrit of over 49% in men and 48% in women (WHO 2017). Primary polycythaemiais caused by erythropoietin (EPO) receptor mutations or Janus Kinase 2 (JAK2) mutations. Secondary polycythaemia is occasionally seen with renal diseases such as cystic kidney disease, tumours, renal artery stenosis and after renal transplantation. Polycythaemia associated with Nephrotic Syndrome (NS) is very rare. This association was first described by Emmanuel DA and Wenzel FJ in 1962. Here, we describe four patients with NS who had polycythaemia at presentation.Heavy protienuria leading to renal interstitial oedema causing hypoxia and increased EPO production and high serum IL8 and increased stability of IL8 mRNA(in minimal change disease) are thought to cause secondary polycythaemia in NS. The resolution of polycythaemia following reduction in proteinuria further strengthens the causation.The exact pathogenesis remains to be elucidated. This is a retrospective observational study conducted in NU Hospitals, Bengaluru, India.There were four patients with NS and polycythaemia, between February 2015 to May 2021. All patients with NSwere subjected to biochemical investigations and ultrasonography (USG) of the abdomen after a detailed history and physical examination as per our hospital protocol. Coagulation profile and blood grouping were done prior to renal biopsy. Percutaneous renal biopsy was done under real-time USG guidance. The tissue obtained was sent for Light microscopic examination, Immunofluorescence microscopy and Electron microscopy. In view of the polycythaemia, all these patients underwent a Chest X Ray, arterial blood gas (ABG) analysis, serum EPO and serum JAK2 mutation studies. All four patients in our study were men. Mean age was 32.25 ± 11.70 years. Mean Hb was 18.75 ± 1.22 g/dL. Mean hematocrit was 54.67 ± 6.5 %. Mean proteinuria at onset was 7.62 ± 7.45 grams/day. Mean serum creatinine at the onset was 1.30 ± 0.58 mg/dL. None had splenomegaly. All had normal total white cell and platelet count. None were smokers. ABG was normal in all. All patients had normal serum EPO levels (mean 3.4±1.64 mU/ml) and negative JAK2 mutation analysis. The etiology of NS was minimal change disease (MCD), primary membranous nephropathy (MGN), primary focal segmental glomerulosclerosis (FSGS) and IgA nephropathy in each one of them. PLA2R antibodies were positive in the serum and renal tissue of the patient with MGN.Immunosuppression was initiated in all patients except the patient with IgA nephropathy who had significant chronicity. Three out of four patients had resolution of polycythemia in parallel with remission of NS.The patient with MCD was detected to have polycythaemia during a relapse. This study highlights polycythaemia as an unusual complication of NS.Most cases of NS and polycythemia documented in the literature correspond to FSGS, mainly associated with polycythaemia vera. There are case reports of secondary polycythaemia associated with primary FSGS, MGN and MCD. We didn't do IL8 and IL11 assay in our patients. To the best of our knowledge ours is probably the largest case series of polycythaemia associated with NS.

The endocrine kidney: tampering with oxygen sensors may change your character

The endocrine kidney: tampering with oxygen sensors may change your character

TP0463518 (TS-143) Ameliorates Peptidoglycan-Polysaccharide Induced Anemia of Inflammation in Rats.

TP0463518 (TS-143) is a competitive prolyl hydroxylase 1/2/3 pan-inhibitor, and has been shown to specifically stabilize hypoxia-inducible factor-2 alpha in the liver to increase erythropoietin production. While TP0463518 has been shown to improve renal anemia, its effect on anemia of inflammation is still unknown. In this study, we created a rat model of anemia of inflammation by administering peptidoglycan-polysaccharide (PG-PS) to Lewis rats; the PG-PS-treated rats developed anemia within 2 weeks after the PG-PS challenge. The hematopoietic effects of oral TP0463518 administration at 10 mg/kg once daily for 6 weeks were examined in this rat model. The hematocrit values in the TP0463518-treated group increased significantly from 32.8 ± 0.8 to 44.5 ± 2.1% after the treatment, which was comparable to that in the healthy control group. The change of the mean corpuscular volume following TP0463518 treatment was similar to that in the healthy control group up to week 4, and significantly higher than that in the vehicle-treated group. TP0463518 increased divalent metal transporter 1 and duodenal cytochrome b expressions in the intestine. Conversely, TP0465318 did not exert any effects on the expressions of genes involved in iron metabolism in the liver, even though TP0463518 dramatically increased erythropoietin expression. Furthermore, TP0463518 had no effect on the expressions of inflammation markers in the liver. These results suggest that TP0463518 increased iron absorption and improved anemia of inflammation without exacerbating liver inflammation. TP0463518 appears to have an acceptable safety profile and could become a useful new therapeutic option for anemia of inflammation.

Can the complete blood count be used as a reliable screening tool for obstructive sleep apnea?

Since hypoxia increases erythropoietin production and inflammation, the complete blood count (CBC) has been proposed as an inexpensive alternative for obstructive sleep apnea (OSA) screening. The objective of this study was to determine whetheror not intermittent hypoxia and OSA severity, as measured by the mean oxygen saturation (SpO2) and apnea-hypopnea index (AHI), affect parameters measured by the CBC. This retrospective study included a total of 941 surgical patients who had a pre-operative home sleep study. The pre-operative CBC was extracted from the electronic patient records. Patients were stratified according to their AHI scores, into mild (AHI ≥ 5- < 15), moderate (AHI ≥ 15- < 30), and severe (AHI ≥ 30) OSA groups. There were 244 patients without OSA, 294 with mild, 223 with moderate, and 180 with severe OSA. Our analysis showed that hemoglobin (P = 0.010), hematocrit (P = 0.027), and basophils (P = 0.006) showed significant changes among the different severities of OSA. For mean SpO2, there were negative associations with body mass index (r = - 0.287; P < 0.001), age (r = - 0.077; P = 0.021), hemoglobin (r = - 0.208; P < 0.001), hematocrit (r = - 0.220; P < 0.001), red blood cells (r = - 0.107; P = 0.001), mean corpuscular volume (MCV) (r = - 0.159; P < 0.001), mean corpuscular hemoglobin (r = - 0.142; P < 0.001), and basophils (r = - 0.091; P = 0.007). All analyzed parameters remained within normal clinical range. Multivariable regression identified hemoglobin, MCV, and basophils to be independent predictors of mean SpO2 and AHI. Hemoglobin, MCV, and basophils were independently associated with intermittent hypoxia defined by mean SpO2 and AHI. Adding CBC parameters to other screening tools for OSA may have additional value due to its association with changes in mean SpO2.

PENGARUH PEMBERIAN JUS BAYAM MERAH (AMARANTHUS GANGETICUS) TERHADAP PENINGKATAN KADAR HEMOGLOBIN PADA IBU HAMIL PENDERITA ANEMIA DI KLINIK SALMA KEC.PERBAUNGAN TAHUN 2020

Anemia in pregnant women greatly affects iron deficiency, because in pregnancy the need for oxygen is higher, which triggers an increase in erythropoietin production (Cunninggham, 2016). (WHO, 2010), globally the prevalence of anemia in pregnant women worldwide is 41.8%. The prevalence of anemia in pregnant women in Indonesia increased compared to 2013, in 2013 as many as 37.1% of pregnant women were anemic while in 2018 it increased to 48.9% (Riskesdas, 2018). One alternative to meet iron needs can be done by consuming vegetables, one of which is red spinach. The aim is to determine the effect of giving red spinach juice on increasing hemoglobin levels in pregnant women with anemia at the Salma Clinic, Perbaungan district in 2020. The method of pre-experimental research was one group pretest-posttest study design. The population in this study were all 28 pregnant women. January to May 2020. Sampling using purposive sampling technique. To determine the differences in the production of Hb levels before and after intervention in pregnant women and Hb Check. The statistical test used in this study was the paired sample T-Test, if the p value was ≤ 0.05. The results of the analysis test using paired sample t-test in the experimental group obtained a value of p = 0.025 &lt;(α = 0.05), it can be concluded that the hypothesis in this study was accepted, namely the effect of giving red spinach juice on pregnant women with anemia at the Salmah Perbaungan Clinic, Serdang Bedagai Regency

Profile of Daprodustat in the Treatment of Renal Anemia Due to Chronic Kidney Disease.

Anemia is a major complication of chronic kidney disease (CKD), which mainly results from appropriate erythropoietin production impairment. Prolyl hydroxylase domain (PHD) inhibitors are currently being developed and approved in some countries as a new treatment for CKD patients with anemia due to the stabilization of intracellular hypoxia-inducible factor (HIF) 1α and HIF2α by PHD inhibition. Daprodustat is one of the orally administrated small-molecule HIF-PH inhibitors, leading to an increase in erythropoietin production, which is regulated by HIF. Also, daprodustat is expected to improve iron metabolism. Recently, several clinical trials showed its efficacy and safety in both hemodialysis- and non-hemodialysis- dependent CKD patients. In addition, some international Phase 3 studies are underway to confirm these effects and reveal the safety profile. This article summarizes the development process and results of each clinical trial.

Long-Term Effects of Environmental Lead on Erythropoietin Production in Young Adults: A Follow-Up Study of a Prospective Cohort in Kosovo.

Background and Aims Epidemiologic cross-sectional studies examining the relationship between environmental lead (Pb) exposure and erythropoietin (EPO) production have reported contrasting results. It is unknown, however, if exposure to Pb earlier in life has an effect on EPO production later in life. Here, using a prospective study, we evaluate the association between prenatal, early childhood, and concurrent Pb exposure and EPO concentration in young adulthood. Methods From our prospective birth cohort study in Mitrovica (a mining town) and Pristina (a control town), Kosovo, from 1985 to 1998, we located and assessed blood lead concentration (BPb) and serum EPO in 101 participants (mean age 24.9 years) in 2011. We examined the association between BPb and EPO, stratified by hemoglobin (Hgb), and controlling for potential confounders. Results These results resemble the findings in the original full cohort at 4.5 and 6.5 years of age, at which time we reported that the maintenance of a normal Hgb required increased EPO production among participants exposed to high levels of environmental Pb. In contrast, when the original cohort was 9.5 and 12 years of age, they were no longer capable of hyper-production of EPO in order to maintain normal levels of Hgb, suggestive of cumulative toxicity to the peritubular cells of the kidney that are responsible for EPO synthesis. Conclusion Our results, along with previously reported findings on this cohort, suggest that a dramatic reduction of Pb exposure may allow for a reversal of the impact that prolonged Pb exposure may have on EPO production.

Artificial blood: where are we now?

Background. The creation of artificial blood (AB) and/or its components can change medicine, but currently available artificial oxygen carriers (AOC) do not perform other blood functions: vascular volume maintenance, coagulation, immunity, transport of neurotransmitters, nutrients and waste.&#x0D; Objective. To describe the current situation regarding AB.&#x0D; Materials and methods. Analysis of literature data on this issue.&#x0D; Results and discussion. The need to create an AB is justified by the high cost of collecting, processing and storing donor blood, low infectious safety of drugs received against HIV, viral hepatitis B and C, cytomegalovirus, etc., reduction of the number of donors, problems with blood incompatibility. Immunological effects of blood transfusions are associated with a higher frequency of infectious processes during surgery, slowing of wound healing and progression of malignant diseases. Requirements for an ideal AB preparation include adequate oxygen uptake and delivery under physiological conditions, no toxic or physiological effects, ability to be eliminated and excreted by the human body, sufficient intravascular half-life, ease of use and storage, stability at room temperature, universal compatibility, availability and low cost, ability to maintain blood pressure and pH, viscosity similar to real blood. Available AOC include oxygen-transport solutions based on hemoglobin and perfluorocarbon compounds (PFC) in the form of emulsions. Natural (human, bovine) or genetically modified hemoglobin is used for the production of the former, and hemoglobin of yeast or bacterial origin can also be used. The advantages of hemoglobin solutions include the increased erythropoietin production, adequate oxygen delivery at a hemoglobin level of 20 g/L without side effects, complete absence of virus transmission and 25 % better reperfusion recovery than with real blood. Potential fields of AOC use include shock, organ ischemia, erythrocyte incompatibility, acute lung injury, organ storage for transplantation, cardioplegia, sickle cell anemia, tumor treatment, and air embolism. The main problem is the release of pro-inflammatory cytokines in response to hemoglobin solution administration. Side effects of these solutions include neuro- and nephrotoxicity, immunosuppression, vasoconstriction, coagulopathy, release of free radicals, and errors in blood tests. In turn, PFC does not bind oxygen, but dissolves it in proportion to the partial pressure. PFC are eliminated by phagocytes and eventually excreted by the lungs during respiration. PFC particles are much smaller than natural erythrocytes (0.2 vs. 7 μm) and are easier to deform, which facilitates their delivery to ischemic areas. Side effects of PFC include transient face flushing, headache and back pain, nausea, fever, anaphylactoid reactions, bleeding tendency, pulmonary edema, and acute right ventricular failure. Because high partial pressures are required to achieve the desired PFC effects, artificial lung ventilation may be required. In addition to hemoglobin-based AOC and PFC, hemoglobin in liposomal erythrocyte form, hemoglobin in nanocapsules, nanoarchitectonic complexes of hemoglobin are under development.&#x0D; Conclusions. 1. The creation of AB may revolutionize medicine. 2. The need to create an AB is justified by the high cost of collection, processing and storage of donor blood, its low infectious safety, reduction of the number of donors, problems due to blood incompatibility. 3. AOC include hemoglobin-based oxygen-transporting solutions and PFC emulsions. 4. Further studies are needed to improve existing AB preparations and create new ones.

Genetic Association of Clinical Complications for Genes Differentially Expressed in Reticulocytes of Sickle Cell Anemia

Introduction Sickle cell anemia (SCA) is characterized by hemolysis, a tissue hypoxia-driven increase in erythropoietin production, and a marked reticulocytosis reflecting stress erythropoiesis. Reticulocytes in SCA constitute 4-15% or more of peripheral red blood cells. Sickle reticulocytes express adhesion molecules that are normally cleared by exosome shedding, including α4β1 integrin, which is thought to contribute to vaso-occlusive crises by binding to vascular endothelial cell vascular cell adhesion molecule 1. Our recent study of the reticulocyte transcriptome in SCA versus healthy African Americans, using RNA-Seq, revealed differential genes that were implicated in a broad range of biological processes including terminal erythroid differentiation, the unfolded protein response, and altered membrane systems. In this study, we assessed the genetic association of these differential genes with disease complications relevant to sickle reticulocytes. Methods We analyzed vaso-occlusive complications including episodic severe pain and chronic avascular necrosis. We also analyzed hemolysis and anemia measured by a hemolysis index and hemoglobin concentration, respectively. The patient cohort combined 525 adolescent and adult patients from Walk PHaSST and 377 pediatric patients from PUSH. Genomic DNA isolated from peripheral blood mononuclear cells of Walk-PHaSST and PUSH patients were genotyped using Illumina Human 610-Quad SNP array and the genotypes were phased and imputed to 1000 genomes phase 3 data. Single nucleotide polymorphisms (SNPs) with minor allele frequency (MAF) &amp;gt;0.01 and imputation r2&amp;gt;0.7 were tested for gene-wise genetic association using SKAT. For severe pain and avascular necrosis, the covariates included age, gender, β globin genotype severity (HHbSS and HbSβ0-thalassemia versus HbSC and HbSβ+-thalassemia), and population stratification. For hemolysis and hemoglobin concentration, the covariates included age, gender, β globin genotype severity, alpha thalassemia, hydroxyurea treatment, recent blood transfusion, and population stratification. Results A total of 111 genes were analyzed. These genes were classified into 13 functional categories based on published research (transcription, post-transcription, translation, histone modification, cell cycle arrest, mitophagy, metabolism, iron homeostasis, antioxidative system, unfolded protein response, membrane skeleton and structural proteins, membrane adhesion molecules and blood group antigens, and membrane transporters). For each functional class, the number of significant gene-wise associations the functional class contains was compared to the number of significant associations from the other classes combined. Defining significance of gene-wise association at nominal P=0.05, we found that the "Unfolded protein response" contained more significant gene-wise associations with severe pain than the other functional classes (one-sided Fisher's exact test P=0.046), driven by genes FUCA1 (alpha-L- fucosidase) and CLN8 (associated with endoplasmic reticulum function). "Membrane skeleton and structural proteins" showed a trend of enrichment for hemolysis (P=0.057), driven by genes MYO5B and CD2AP, and for avascular necrosis (P=0.075), driven by genes MYLK, CAVIN2 and PALLD. Defining the significance of gene-wise association at a less stringent nominal P=0.1, "membrane adhesion molecules and blood group antigens" showed a trend of enrichment in association with severe pain (P=0.097), driven by genes GYPA, ITGA4 and ITGB1, the latter two encoding α4β1 integrin subunits which are abnormally present on the reticulocyte membrane and have been implicated in sickle vaso-occlusion. Regional scans revealed the SNPs with the most significant associations within these genes. Discussion Our results reveal enrichment of genetic association with vaso-occlusive and hemolytic complications in gene functional categories that showed altered expression in sickle reticulocytes. Future study is needed to validate these associations. Disclosures Gordeuk: CSL Behring: Consultancy, Research Funding; Global Blood Therapeutics: Consultancy, Research Funding; Imara: Research Funding; Ironwood: Research Funding; Novartis: Consultancy.

Collagen Hydrolysate Corrects Anemia in Chronic Kidney Disease via Anti-Inflammatory Renoprotection and HIF-2α-Dependent Erythropoietin and Hepcidin Regulation.

Anemia is a common chronic kidney disease (CKD) complication contributing to increased morbidity and mortality. Collagen-based traditional Chinese nutraceuticals have long been used in antianemic therapies. This study aims to investigate the therapeutic effectiveness of porcine collagen hydrolysate (CH) and its underlying mechanism in the treatment of renal anemia by using adenine-induced CKD mice, RAW264.7 macrophages, and HepG2 hepatoma cells, with prolyl-hydroxyproline as a reference compound for collagen-derived hydroxyproline-containing di-/tripeptides. CH was found to alleviate renal filtering dysfunction, systemic and kidney inflammation, liver hepcidin overproduction and anemia and to increase erythropoietin production and hypoxia inducible factor (HIF)-2α stability in liver and kidney in CKD mice. Prolyl-hydroxyproline exerted direct anti-inflammatory effects on lipopolysaccharide-activated macrophages and elicited stimulating and inhibiting activities on erythropoietin expression and hepcidin overproduction, respectively, in HepG2 cells by HIF-2α activation. Overall, CH was effective in correcting renal anemia via anti-inflammatory renoprotection and HIF-2α-dependent erythropoietin and hepcidin regulation.

Nonclinical Characterization of the Hypoxia-Inducible Factor Prolyl Hydroxylase Inhibitor Roxadustat, a Novel Treatment of Anemia of Chronic Kidney Disease.

Anemia of chronic kidney disease (CKD) is a multifactorial disorder caused by impaired erythropoietin (EPO) production and altered iron homeostasis associated with inflammation. Hypoxia-inducible factor (HIF) is a transcription factor that stimulates erythropoiesis via a coordinated response involving increased EPO production and enhanced iron availability for Hb synthesis. HIF degradation is regulated by HIF-prolyl hydroxylase (HIF-PH) enzymes. We hypothesized that roxadustat, an orally available small-molecule inhibitor of HIF-PH, would increase EPO production and promote erythropoiesis in animal models of anemia. In cells, roxadustat increased both HIF-1α and HIF-2α proteins, leading to an increase in EPO production, even in the presence of EPO-suppressing inflammatory cytokines. Roxadustat administered intermittently to healthy rats and cynomolgus monkeys increased circulating EPO levels, reticulocytes, blood Hb, and hematocrit in a dose-dependent manner. Roxadustat corrected anemia in a rat model of CKD after five-sixth nephrectomy and in a rat model of anemia of inflammation with impaired iron metabolism induced by peptidoglycan-polysaccharide (PG-PS). In the PG-PS model, roxadustat significantly decreased hepatic expression of hepcidin, a hormone responsible for iron sequestration and functional iron deficiency, and increased expression of two genes involved in duodenal iron absorption: divalent metal transporter 1 and duodenal cytochrome b. In conclusion, by activating the HIF pathway, roxadustat increased EPO production, elevated Hb, corrected anemia, and improved iron homeostasis. The coordinated erythropoietic response stimulated by roxadustat, involving both EPO production and mobilization of iron stores, makes this compound a promising treatment of anemia of CKD and anemia associated with functional iron deficiency. SIGNIFICANCE STATEMENT: Roxadustat is a novel orally available small-molecule inhibitor of HIF prolyl hydroxylase enzymes that reversibly stabilizes HIF-α, thus activating transcription of HIF-dependent genes, including EPO and regulators of iron homeostasis. Activation of the HIF pathway by roxadustat induces erythropoiesis in healthy rats and monkeys and corrects experimentally induced anemia in rats. The coordinated erythropoietic response that increases EPO production and mobilizes iron stores makes roxadustat a promising treatment for anemia of chronic kidney disease and anemia associated with functional iron deficiency.

Stabilizing HIF to Ameliorate Anemia

Erythropoietin (EPO) production in the kidney is regulated by the oxygen-sensing transcription factor HIF-1α, which is degraded under normoxic conditions by HIF-prolyl hydroxylase (HIF-PHD). Inhibition of HIF-PHD by roxadustat leads to increased EPO production, better iron absorption, and amelioration of anemia in chronic kidney disease (CKD).