Erythropoietin and Nonhematopoietic Effects

Advancing stroke recovery: unlocking the potential of cellular dynamics in stroke recovery

Stroke stands as a predominant cause of mortality and morbidity worldwide, and there is a pressing need for effective therapies to improve outcomes and enhance the quality of life for stroke survivors. In this line, effective efferocytosis, the clearance of apoptotic cells, plays a crucial role in neuroprotection and immunoregulation. This process involves specialized phagocytes known as "professional phagocytes" and consists of four steps: "Find-Me," "Eat-Me," engulfment/digestion, and anti-inflammatory responses. Impaired efferocytosis can lead to secondary necrosis and inflammation, resulting in adverse outcomes following brain pathologies. Enhancing efferocytosis presents a potential avenue for improving post-stroke recovery. Several therapeutic targets have been identified, including osteopontin, cysteinyl leukotriene 2 receptor, the µ opioid receptor antagonist β-funaltrexamine, and PPARγ and RXR agonists. Ferroptosis, defined as iron-dependent cell death, is now emerging as a novel target to attenuate post-stroke tissue damage and neuronal loss. Additionally, several biomarkers, most importantly CD163, may serve as potential biomarkers and therapeutic targets for acute ischemic stroke, aiding in stroke diagnosis and prognosis. Non-pharmacological approaches involve physical rehabilitation, hypoxia, and hypothermia. Mitochondrial dysfunction is now recognized as a major contributor to the poor outcomes of brain stroke, and medications targeting mitochondria may exhibit beneficial effects. These strategies aim to polarize efferocytes toward an anti-inflammatory phenotype, limit the ingestion of distressed but viable neurons, and stimulate efferocytosis in the late phase of stroke to enhance post-stroke recovery. These findings highlight promising directions for future research and development of effective stroke recovery therapies.

Pharmacological Treatment of Degenerative Cervical Myelopathy: A Critical Review of Current Evidence

Degenerative cervical myelopathy (DCM) is the leading cause of spinal cord dysfunction in adults, representing substantial morbidity and significant financial and resource burdens. Typically, patients with progressive DCM will eventually receive surgical treatment. Nonetheless, despite advancements in pharmacotherapeutics, evidence for pharmacological therapy remains limited. Health professionals from various fields would find interest in pharmacological agents that could benefit patients with mild DCM or enhance surgical outcomes. This review aims to consolidate all clinical and experimental evidence on the pharmacological treatment of DCM. We conducted a comprehensive narrative review that presents all pharmacological agents that have been investigated for DCM treatment in both humans and animal models. Riluzole exhibits effectiveness solely in rat models, but not in treating mild DCM in humans. Cerebrolysin emerges as a potential neuroprotective agent for myelopathy in animals but had contradictory results in clinical trials. Limaprost alfadex demonstrates motor function improvement in animal models and exhibits promising outcomes in a small clinical trial. Glucocorticoids not only fail to provide clinical benefits but may also lead to adverse events. Cilostazol, anti-Fas ligand antibody, and Jingshu Keli display promise in animal studies, while erythropoietin, granulocyte colony-stimulating factor and limaprost alfadex exhibit potential in both animal and human research. Existing evidence mainly rests on weak clinical data and animal experimentation. Current pharmacological efforts target ion channels, stem cell differentiation, inflammatory, vascular, and apoptotic pathways. The inherent nature and pathogenesis of DCM offer substantial prospects for developing neurodegenerative or neuroprotective therapies capable of altering disease progression, potentially delaying surgical intervention, and optimizing outcomes for those undergoing surgical decompression.

Delayed treatment with erythropoietin attenuates renal fibrosis in mouse model of unilateral ureteral obstruction

OBJECTIVES

Erythropoietin (EPO) exerts tissue-protective effects on various organs including the kidney. However, the effects of EPO on established renal fibrosis remain unclear. In this study, we aimed to examine the therapeutic potential of EPO against established renal fibrosis.

METHODS

Renal fibrosis was induced in mice by unilateral ureteral obstruction (UUO) and the mice were treated with recombinant human EPO (rhEPO) daily during 7 and 13 days after UUO. The degrees of renal fibrosis, myofibroblast accumulation, and macrophage infiltration; the mRNA expression levels of transforming growth factor (TGF)-β1 and α1(I) collagen; and the protein levels of Kelch-like ECH-associated protein 1 (Keap1) and nuclear NF-E2-related factor 2 (Nrf2) in the kidneys were assessed on day 14 after UUO.

RESULTS

Treatment with rhEPO significantly decreased fibrosis, myofibroblast accumulation, and α1(I) collagen mRNA expression, but it did not significantly affect TGF-β1 mRNA expression. Although treatment with rhEPO did not significantly affect the total number of interstitial macrophages, it significantly decreased the number of CD86-positive cells (M1 macrophages), while significantly increased the number of CD206-positive cells (M2 macrophages) in the interstitium. Treatment with rhEPO did not affect the Keap1/Nrf2 protein level or the peripheral blood hematocrit value.

CONCLUSIONS

These results indicate for the first time that EPO exerts antifibrotic effects against the evolution of established renal fibrosis, possibly by influencing the polarization of infiltrating macrophages.

Strategies to therapeutically modulate cytokine action

Cytokines are secreted or membrane-presented molecules that mediate broad cellular functions, including development, differentiation, growth and survival. Accordingly, the regulation of cytokine activity is extraordinarily important both physiologically and pathologically. Cytokine and/or cytokine receptor engineering is being widely investigated to safely and effectively modulate cytokine activity for therapeutic benefit. IL-2 in particular has been extensively engineered, to create IL-2 variants that differentially exhibit activities on regulatory T cells to potentially treat autoimmune disease versus effector T cells to augment antitumour effects. Additionally, engineering approaches are being applied to many other cytokines such as IL-10, interferons and IL-1 family cytokines, given their immunosuppressive and/or antiviral and anticancer effects. In modulating the actions of cytokines, the strategies used have been broad, including altering affinities of cytokines for their receptors, prolonging cytokine half-lives in vivo and fine-tuning cytokine actions. The field is rapidly expanding, with extensive efforts to create improved therapeutics for a range of diseases.

The impact of COVID-19 infection before the vaccination era on the hospitalized patients requiring hemodialysis: a single-center retrospective cohort

Due to effective vaccinations, the COVID-19 (coronavirus disease 2019) infection that caused the pandemic has a milder clinical course. We aimed to assess the mortality of hospitalized COVID-19 patients before the vaccination era. We investigated the mortality in those patients between 1 October 2020 and 31 May 2021 who received hemodialysis treatment [patients with previously normal renal function (nCKD), patients with chronic kidney disease previously not requiring hemodialysis (CKDnonHD), chronic kidney disease (CKD), and patients on regular hemodialysis (pHD)]. In addition, participants were followed up for all-cause mortality in the National Health Service database until 1 December 2021. In our center, 83 of 108 (76.9%) were included in the analysis due to missing covariates. Over a median of 26 (interquartile range 11-266) days of follow-up, 20 of 22 (90.9%) of nCKD, 23 of 24 (95.8%) of CKDnonHD, and 17 of 37 (45.9%) pHD patients died (p < 0.001). In general, patients with nCKD had fewer comorbidities but more severe presentations. In contrast, the patients with pHD had the least severe symptoms (p < 0.001). In a model adjusted for independent predictors of all-cause mortality (C-reactive protein and serum albumin), CKDnonHD patients had increased mortality [hazard ratio (HR) 1.91, 95% confidence interval (CI), 1.02-3.60], while pHD patients had decreased mortality (HR 0.41, 95% CI 0.20-0.81) compared to nCKD patients. After further adjustment for the need for intensive care, the difference in mortality between the nCKD and pHD groups became non-significant. Despite the limitations of our study, it seems that the survival of previously hemodialysis patients was significantly better.

Erythropoietin ameliorates cognitive deficits by improving hippocampal and synaptic damage in streptozotocin-induced diabetic mice

Recent studies have shown that erythropoietin (EPO) is an effective neuroprotective and neurotrophic agent for neurological disorders, such as traumatic brain injury and Alzheimer's disease. However, the effectiveness of EPO administration against diabetic cognitive impairments has rarely been examined. In this study, we investigated the effects of EPO on streptozotocin (STZ)-induced male C57BL/6 J mice. Then, we sought to clarify the mechanisms of EPO-mediated neuroprotection in high-glucose (HG)-stimulated HT22 cells. In vivo, we found that STZ-induced diabetic mice showed impaired spatial learning and memory, which was alleviated by EPO treatment. EPO also significantly lowered elevated fasting blood glucose levels, improved pancreatic and hippocampal damage, and restored oxidative stress in the STZ-induced diabetic mice. In vitro, EPO markedly increased cell viability, restrained the expression of pro-apoptotic Bax, enhanced the expression of pro-caspase 3, anti-apoptotic Bcl-2, brain-derived neurotrophic factor (BDNF) and postsynaptic density 95 (PSD-95), and attenuated the upregulation of N-methyl-d-aspartic acid (NMDA) receptor subunits NR1, NR2A and NR2B in HG-induced HT22 cells. The protective effects of EPO was obviously abolished by treatment with an NMDA receptor agonist. Our findings revealed that EPO impedes hippocampal and synaptic damage and neuronal apoptosis by regulating BDNF and PSD-95 expression through NMDA receptors, thereby ameliorating cognitive impairments in mice with T1DM.

Variation Patterns of Hemoglobin Levels by Gestational Age during Pregnancy: A Cross-Sectional Analysis of a Multi-Center Retrospective Cohort Study in China

Background: Pregnancy anemia is a global health concern. However, to our knowledge, there still has little consensus on the reference value of hemoglobin levels. Particularly, little evidence from China was accessible in most existing guidelines. Objective: To evaluate hemoglobin levels and anemia prevalence of pregnant women in China and offer evidence for anemia and its reference values in China. Methods: A multi-center retrospective cohort study was conducted among 143,307 singleton pregnant women aged 15–49 at 139 hospitals in China, with hemoglobin concentrations routinely tested at each prenatal visit. Subsequently, a restricted cubic spline was performed to reveal a non-linear variation of hemoglobin concentrations during the gestational week. The Loess model was used to describe the changes in the prevalence of different degrees of anemia with gestational age. Multivariate linear regression model and Logistic regression model were applied to explore influencing factors of gestational changes in hemoglobin level and anemia prevalence, respectively. Results: Hemoglobin varied nonlinearly with gestational age, and the mean hemoglobin levels decreased from 125.75 g/L in the first trimester to 118.71 g/L in the third trimester. By analyzing hemoglobin levels with gestational age and pregnancy period, we proposed new criteria according to 5th percentile hemoglobin concentration in each trimester as a reference for anemia, with 108 g/L, 103 g/L, and 99 g/L, respectively. According to WHO’s criteria, the prevalence of anemia sustainably increased with gestational age, with 6.2% (4083/65,691) in the first trimester, 11.5% (7974/69,184) in the second trimester and 21.9% (12,295/56,042) in the third trimester, respectively. In subsequent analysis, pregnant women in non-urban residents, multiparity, and pre-pregnancy underweight tended to have lower hemoglobin levels. Conclusions: This research, the first large-sample study to present a set of gestational age-specific reference centiles for hemoglobin levels in China, could be used to obtain a better understanding of the overall levels of hemoglobin in Chinese healthy pregnant women and ultimately offer clues for a more precise hemoglobin reference value of anemia in China.

The effect of preconditioning agents on cardiotoxicity and neurotoxicity of carbon monoxide poisoning in animal studies: a systematic review

BACKGROUND

Carbon monoxide (CO) poisoning is a common intoxication and many people die yearly due to CO poisoning and preconditioning agents attenuate brain and cardiac injury caused by intoxication. It is critical to fully understand the efficacy of new methods to directly target the toxic effect of CO, such as conditioning agents, which are currently under development. This study aims to systematically investigate current evidence from animal experiments and the effects of administration preconditions in acute and late phases after CO poisoning on cardiotoxicity and neurotoxicity.

METHODS

Four databases (PubMed, Embase, Scopus, and Web of Science) were systematically searched without language restrictions, and hand searching was conducted until November 2021. We included studies that compare preconditioning agents with the control group after CO poisoning in animals. The SYRCLE RoB tool was used for risk of bias assessments.

RESULTS

Thirty-seven studies were included in the study. Erythropoietin, granulocyte colony-stimulating factor (GCSF), hydrogen-rich saline, and N-butylphthalide (NBP) were found to have positive effects on reducing neurotoxicity and cardiotoxicity. As other preconditions have fewer studies, no valuable results can be deduced. Most of the studies were unclear for sources of bias.

DISCUSSION

Administration of the examined preconditioning agents including NBP, hydrogen-rich saline, and GCSF in acute and late phases could attenuate neurotoxicity and cardiotoxicity of CO poisoned animals. For a better understanding of mechanisms and activities, and finding new and effective preconditioning agents, further preclinical and clinical studies should be performed to analyze the effects of preconditioning agents.

Prospects for Neurotrophic Factor-Based Early Intervention in Schizophrenia: Lessons Learned from the Effects of Antipsychotic Drugs on Cognition, Neurogenesis, and Neurotrophic Factors

Although reducing psychotic symptoms in schizophrenia has been a major focus of therapeutic interventions for decades, improving cognition is considered a better predictor of functional outcomes. However, the most commonly prescribed antipsychotic drugs (APDs) show only marginal beneficial effects on cognition in patients with schizophrenia. The neural mechanisms underlying cognitive disturbances in schizophrenia remain unknown that making drug development efforts very challenging. Since neurotrophic factors are the primary architects of neurogenesis, synaptic plasticity, learning, and memory, the findings from preclinical and clinical studies that assess changes in neurogenesis and neurotrophic factors and their relationship to cognitive performance in schizophrenia, and how these mechanisms might be impacted by APD treatment, may provide valuable clues in developing therapies to combat cognitive deficit in schizophrenia. Numerous evidence produced over the years suggests a deficit in a wide spectrum of neurotrophic factors in schizophrenia. Since schizophrenia is considered a neurodevelopmental disorder, early intervention with neurotrophic factors may be more effective in ameliorating the cognitive deficits and psychopathological symptoms associated with this pathology. In this context, results from initial clinical trials with neurotrophic factors and their future potential to improve cognition and psychosocial functioning in schizophrenia are discussed.

Serum anti-erythropoietin antibodies among pregnant women with Plasmodium falciparum malaria and anaemia: A case-control study in northern Ghana

BACKGROUND

Anaemia in pregnancy is common in underdeveloped countries, and malaria remains the predominant cause of the condition in Ghana. Anti-erythropoietin (anti-EPO) antibody production may be implicated in the pathogenesis of Plasmodium falciparum malaria-related anaemia in pregnancy. This study ascertained the prevalence of anti-EPO antibody production and evaluated the antibodies' relationship with Plasmodium falciparum malaria and malaria-related anaemia in pregnancy.

METHODS

This hospital-based case-control study recruited a total of 85 pregnant women (55 with Plasmodium falciparum malaria and 30 controls without malaria). Venous blood was taken from participants for thick and thin blood films for malaria parasite microscopy. Complete blood count (CBC) analyses were done using an automated haematology analyzer. Sandwich enzyme-linked immunosorbent assay (ELISA) was used to assess serum erythropoietin (EPO) levels and anti-EPO antibodies. Data were analyzed using IBM SPSS version 22.0.

RESULTS

Haemoglobin (p<0.001), RBC (p<0.001), HCT (p = 0.006) and platelet (p<0.001) were significantly lower among pregnant women infected with Plasmodium falciparum. Of the 85 participants, five (5.9%) had anti-EPO antibodies in their sera, and the prevalence of anti-EPO antibody production among the Plasmodium falciparum-infected pregnant women was 9.1%. Plasmodium falciparum-infected pregnant women with anti-EPO antibodies had lower Hb (p<0.001), RBC (p<0.001), and HCT (p<0.001), but higher EPO levels (p<0.001). Younger age (p = 0.013) and high parasite density (p = 0.004) were significantly associated with Plasmodium falciparum-related anti-EPO antibodies production in pregnancy. Also, younger age (p = 0.039) and anti-EPO antibody production (p = 0.012) related to the development of Plasmodium falciparum malaria anaemia in pregnancy.

CONCLUSION

The prevalence of anti-EPO antibodies among pregnant women with Plasmodium falciparum malaria was high. Plasmodium falciparum parasite density and younger age could stimulate the production of anti-EPO antibodies, and the antibodies may contribute to the development of malarial anaemia in pregnancy. Screening for anti-EPO antibodies should be considered in pregnant women with P. falciparum malaria.

The Association of Erythropoietin and Age-Related Macular Degeneration in Hemodialysis Patients: A Nationwide Population-Based Cohort Study

This population-based retrospective cohort study investigated the effectiveness of erythropoietin (EPO) treatment in reducing the risk of age-related macular degeneration (AMD) in hemodialysis patients, using the National Health Insurance Research Data of Taiwan. From the database, we identified 147,318 end-stage renal disease (ESRD) patients on hemodialysis who had been diagnosed in 2000−2014 to establish the propensity-score-matched EPO user cohort and non-EPO user cohort with equal sample size of 15,992. By the end of 2016, the cumulative incidence of AMD in EPO users was about 3.29% lower than that in non-EPO users (Kaplan−Meier survival p < 0.0001). The risk of AMD was 43% lower in EPO users than in non-EPO users, with an adjusted hazard ratio (aHR) of 0.57 (95% confidence interval (CI) = 0.51−0.64) estimated in the multivariate Cox model. A significant negative dose−response relationship was identified between the EPO dosage and the risk of AMD (p < 0.0001). Another beneficial effect of EPO treatment was a reduced risk of both exudative AMD (aHR = 0.48, 95% CI = 0.40−0.61) and non-exudative AMD (aHR = 0.61, 95% CI = 0.53−0.69), also in similar dose−response relationships (p < 0.0001). Our findings suggest that EPO treatment for hemodialysis patients could reduce AMD risk in a dose−response relationship.

Sodium-Glucose Cotransporter-2 Inhibitors-from the Treatment of Diabetes to Therapy of Chronic Heart Failure

Sodium-glucose cotransporter-2 (SGLT2) inhibitors are currently the second-line pharmacotherapy in type 2 diabetes, particularly through their effectiveness in reducing glycemia, but also due to their cardioprotective and nephroprotective effects. In light of surprisingly satisfactory results from large, randomized trials on gliflozins, SGLT2 received the highest recommendation (Class IA) with the highest level of evidence (A) in the treatment algorithm for HF with reduced LVEF in recent ESC HF guidelines. This great breakthrough in the treatment of HF is due to different mechanisms of action of gliflozins that are reported to be able to change the natural course of HF by reducing the risk of both hospitalization and death. They are recommended regardless of the patient’s diabetes status. This review summarizes the up-to-date literature on their beneficial and pleiotropic impact on the cardiovascular system.

Association of Endogenous Erythropoietin Levels and Iron Status With Cognitive Functioning in the General Population

Background

Emerging data suggest that erythropoietin (EPO) promotes neural plasticity and that iron homeostasis is needed to maintain normal physiological brain function. Cognitive functioning could therefore be influenced by endogenous EPO levels and disturbances in iron status.

Objective

To determine whether endogenous EPO levels and disturbances in iron status are associated with alterations in cognitive functioning in the general population.

Materials and Methods

Community-dwelling individuals from the Prevention of Renal and Vascular End-Stage Disease (PREVEND) study, a general population-based cohort in Groningen, Netherlands, were surveyed between 2003 and 2006. Additionally, endogenous EPO levels and iron status, consisting of serum iron, transferrin, ferritin, and transferrin saturation were analyzed. Cognitive function was assessed by scores on the Ruff Figural Fluency Test (RFFT), as a reflection of executive function, and the Visual Association Test (VAT), as a reflection of associative memory.

Results

Among 851 participants (57% males; mean age 60 ± 13 years), higher endogenous EPO levels were independently associated with an improved cognitive function, reflected by RFFT scores (ß = 0.09, P = 0.008). In multivariable backward linear regression analysis, EPO levels were among the most important modifiable determinants of RFFT scores (ß = 0.09, P = 0.002), but not of VAT scores. Of the iron status parameters, only serum ferritin levels were inversely associated with cognitive function, reflected by VAT scores, in multivariable logistic regression analysis (odds ratio, 0.77; 95% confidence interval 0.63–0.95; P = 0.02 for high performance on VAT, i.e., ≥11 points). No association between iron status parameters and RFFT scores was identified.

Conclusion

The findings suggest that endogenous EPO levels and serum ferritin levels are associated with specific cognitive functioning tests in the general population. Higher EPO levels are associated with better RFFT scores, implying better executive function. Serum ferritin levels, but not other iron status parameters, were inversely associated with high performance on the VAT score, implying a reduced ability to create new memories and recall recent past. Further research is warranted to unravel underlying mechanisms and possible benefits of therapeutic interventions.

Neurogenesis as a Tool for Spinal Cord Injury

Spinal cord injury is a devastating medical condition with no effective treatment. One approach to SCI treatment may be provided by stem cells (SCs). Studies have mainly focused on the transplantation of exogenous SCs, but the induction of endogenous SCs has also been considered as an alternative. While the differentiation potential of neural stem cells in the brain neurogenic regions has been known for decades, there are ongoing debates regarding the multipotent differentiation potential of the ependymal cells of the central canal in the spinal cord (SCECs). Following spinal cord insult, SCECs start to proliferate and differentiate mostly into astrocytes and partly into oligodendrocytes, but not into neurons. However, there are several approaches concerning how to increase neurogenesis in the injured spinal cord, which are discussed in this review. The potential treatment approaches include drug administration, the reduction of neuroinflammation, neuromodulation with physical factors and in vivo reprogramming.

Considerations about Hypoxic Changes in Neuraxis Tissue Injuries and Recovery

Hypoxia represents the temporary or longer-term decrease or deprivation of oxygen in organs, tissues, and cells after oxygen supply drops or its excessive consumption. Hypoxia can be (para)-physiological-adaptive-or pathological. Thereby, the mechanisms of hypoxia have many implications, such as in adaptive processes of normal cells, but to the survival of neoplastic ones, too. Ischemia differs from hypoxia as it means a transient or permanent interruption or reduction of the blood supply in a given region or tissue and consequently a poor provision with oxygen and energetic substratum-inflammation and oxidative stress damages generating factors. Considering the implications of hypoxia on nerve tissue cells that go through different ischemic processes, in this paper, we will detail the molecular mechanisms by which such structures feel and adapt to hypoxia. We will present the hypoxic mechanisms and changes in the CNS. Also, we aimed to evaluate acute, subacute, and chronic central nervous hypoxic-ischemic changes, hoping to understand better and systematize some neuro-muscular recovery methods necessary to regain individual independence. To establish the link between CNS hypoxia, ischemic-lesional mechanisms, and neuro-motor and related recovery, we performed a systematic literature review following the" Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA") filtering method by interrogating five international medical renown databases, using, contextually, specific keywords combinations/"syntaxes", with supplementation of the afferent documentation through an amount of freely discovered, also contributive, bibliographic resources. As a result, 45 papers were eligible according to the PRISMA-inspired selection approach, thus covering information on both: intimate/molecular path-physiological specific mechanisms and, respectively, consequent clinical conditions. Such a systematic process is meant to help us construct an article structure skeleton giving a primary objective input about the assembly of the literature background to be approached, summarised, and synthesized. The afferent contextual search (by keywords combination/syntaxes) we have fulfilled considerably reduced the number of obtained articles. We consider this systematic literature review is warranted as hypoxia's mechanisms have opened new perspectives for understanding ischemic changes in the CNS neuraxis tissue/cells, starting at the intracellular level and continuing with experimental research to recover the consequent clinical-functional deficits better.

The Effect of Erythropoietin and Its Derivatives on Ischemic Stroke Therapy: A Comprehensive Review

Numerous studies explored the therapeutic effects of erythropoietin (EPO) on neurodegenerative diseases. Few studies provided comprehensive and latest knowledge of EPO treatment for ischemic stroke. In the present review, we introduced the structure, expression, function of EPO, and its receptors in the central nervous system. Furthermore, we comprehensively discussed EPO treatment in pre-clinical studies, clinical trials, and its therapeutic mechanisms including suppressing inflammation. Finally, advanced studies of the therapy of EPO derivatives in ischemic stroke were also discussed. We wish to provide valuable information on EPO and EPO derivatives’ treatment for ischemic stroke for basic researchers and clinicians to accelerate the process of their clinical applications.

Severity of Anemia During Pregnancy and Adverse Maternal and Fetal Outcomes

IMPORTANCE

Anemia is the most widespread nutritional deficiency among pregnant females in the world. Despite numerous studies on anemia, evidence is limited about the association of severity of anemia with maternal and fetal health.

OBJECTIVE

To investigate the association between severity of anemia during pregnancy and risk of maternal and fetal adverse outcomes.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study used data from China's Hospital Quality Monitoring System from January 1, 2016, to December 31, 2019, for pregnant females aged 15 to 49 years with birth outcomes reported at 1508 hospitals with maternity services in mainland China.

EXPOSURES

Anemia of varying severity during pregnancy was identified from daily standardized electronic inpatient discharge records using corresponding codes of the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision. Mild anemia was defined as a hemoglobin concentration of 100 to 109 g/L (to convert g/L to g/dL, divide by 10.0); moderate anemia, as 70 to 99 g/L; and severe anemia, as less than 70 g/L.

MAIN OUTCOMES AND MEASURES

The main outcomes included 6 maternal outcomes (placental abruption, preterm birth, severe postpartum hemorrhage, shock, admission to the intensive care unit [ICU], and maternal mortality) and 3 neonatal outcomes (fetal growth restriction, malformation, and stillbirth). Multivariable logistic regression models were used to estimate the odds ratios (ORs) and 95% CIs of these outcomes among pregnant females with varying severity of anemia.

RESULTS

Among 18 948 443 pregnant females aged 15 to 49 years (mean [SD] age, 29.42 [4.87] years), 17.78% were diagnosed with anemia during pregnancy, including 9.04% with mild anemia, 2.62% with moderate anemia, 0.21% with severe anemia, and 5.90% with anemia of unknown severity. Compared with no anemia, anemia severity during pregnancy was associated with increased risks of placental abruption (mild: adjusted OR [aOR], 1.36 [95% CI, 1.34-1.38]; moderate: aOR, 1.98 [95% CI, 1.93-2.02]; severe: aOR, 3.35 [95% CI, 3.17-3.54]), preterm birth (mild: aOR, 1.08 [95% CI, 1.07-1.08]; moderate: aOR, 1.18 [95% CI, 1.17-1.19]; severe: aOR, 1.36 [95% CI, 1.32-1.41]), severe postpartum hemorrhage (mild: aOR, 1.45 [95% CI, 1.43-1.47]; moderate: aOR, 3.53 [95% CI, 3.47-3.60]; severe: 15.65 [95% CI, 15.10-16.22]), and fetal malformation (mild: aOR, 1.15 [95% CI, 1.14-1.17]; moderate: aOR, 1.19 [95% CI, 1.16-1.21]; severe: aOR, 1.62 [95% CI, 1.52-1.73]). Compared with no anemia, moderate or severe anemia were associated with increased risks of maternal shock (moderate: aOR, 1.50 [95% CI, 1.41-1.60]; severe: aOR, 14.98 [95% CI, 13.91-16.13]), ICU admission (moderate: aOR, 1.08 [95% CI, 1.01-1.16]; severe: aOR, 2.88 [95% CI, 2.55-3.25]), maternal death (moderate: aOR, 0.45 [95% CI, 0.30-0.65]; severe: aOR, 1.56 [95% CI, 0.97-2.48], fetal growth restriction (moderate: aOR, 0.80 [95% CI, 0.78-0.82]; severe: aOR, 1.08 [95% CI, 1.00-1.17]), and stillbirth (moderate: aOR,0.79 [95% CI, 0.76-0.81]; severe: aOR, 1.86 [95% CI, 1.75-1.98]), and mild anemia was associated with decreased risks (maternal shock: aOR, 0.67 [95% CI, 0.63-0.71]; ICU admission: aOR, 0.80 [95% CI, 0.76-0.84]; maternal death: aOR, 0.37 [95% CI, 0.29-0.49]; fetal growth restriction: aOR, 0.79 [95% CI, 0.77-0.80]; stillbirth: aOR, 0.59 [95% CI, 0.58-0.61]) after adjusting for sociodemographic characteristics and other complications during pregnancy.

CONCLUSIONS AND RELEVANCE

The findings suggest that anemia during pregnancy is associated with maternal and fetal health outcomes and that mild anemia is associated with improved maternal and fetal survival and fetal growth. Further work is needed to validate the concentration of hemoglobin at which optimal maternal and fetal health are achieved.

Erythropoietin, as a biological macromolecule in modification of tissue engineered constructs: A review

In recent years, tissue engineering has emerged as a promising approach to address limitations of organ transplantation. The ultimate goal of tissue engineering is to provide scaffolds that closely mimic the physicochemical and biological cues of native tissues' extracellular matrix. In this endeavor, new generation of scaffolds have been designed that utilize the incorporation of signaling molecules in order to improve cell recruitment, enhance angiogenesis, exert healing activities, and increase the engraftment of the scaffolds. Among different signaling molecules, the role of erythropoietin (EPO) in regenerative medicine is increasingly being appreciated. It is a biological macromolecule which can prevent programed cell death, modulate inflammation, induce cell proliferation, and provide tissue protection in different disease models. In this review, we have outlined and critically analyzed different techniques of scaffolds' modification with EPO or EPO-loaded nanoparticles. We have also explored different strategies for the incorporation of EPO into scaffolds. Non-hematopoietic functions of EPO have also been discussed. Finalizing with detailed discussion surrounding the applications, challenges, and future perspectives of EPO-modified scaffolds in regenerative medicine.

Hypoxia-Inducible Factor Stabilizers in End Stage Kidney Disease: "Can the Promise Be Kept?"

Anemia is a common complication of chronic kidney disease (CKD). The prevalence of anemia in CKD strongly increases as the estimated Glomerular Filtration Rate (eGFR) decreases. The pathophysiology of anemia in CKD is complex. The main causes are erythropoietin (EPO) deficiency and functional iron deficiency (FID). The administration of injectable preparations of recombinant erythropoiesis-stimulating agents (ESAs), especially epoetin and darbepoetin, coupled with oral or intravenous(iv) iron supplementation, is the current treatment for anemia in CKD for both dialysis and non-dialysis patients. This approach reduces patients’ dependence on transfusion, ensuring the achievement of optimal hemoglobin target levels. However, there is still no evidence that treating anemia with ESAs can significantly reduce the risk of cardiovascular events. Meanwhile, iv iron supplementation causes an increased risk of allergic reactions, gastrointestinal side effects, infection, and cardiovascular events. Currently, there are no studies defining the best strategy for using ESAs to minimize possible risks. One class of agents under evaluation, known as prolyl hydroxylase inhibitors (PHIs), acts to stabilize hypoxia-inducible factor (HIF) by inhibiting prolyl hydroxylase (PH) enzymes. Several randomized controlled trials showed that HIF-PHIs are almost comparable to ESAs. In the era of personalized medicine, it is possible to envisage and investigate specific contexts of the application of HIF stabilizers based on the individual risk profile and mechanism of action.

The Impact of Erythropoietin on Short- and Long-Term Kidney-Related Outcomes in Neonates of Extremely Low Gestational Age. Results of a Multicenter, Double-Blind, Placebo-Controlled Randomized Clinical Trial

OBJECTIVE

To evaluate whether extremely low gestational age neonates (ELGANs) randomized to erythropoietin have better or worse kidney-related outcomes during hospitalization and at 22-26 months of corrected gestational age (cGA) compared with those randomized to placebo.

STUDY DESIGN

We performed an ancillary study to a multicenter double-blind, placebo-controlled randomized clinical trial of erythropoietin in ELGANs.

RESULTS

The prevalence of severe (stage 2 or 3) acute kidney injury (AKI) was 18.2%. We did not find a statistically significant difference between those randomized to erythropoietin vs placebo for in-hospital primary (severe AKI) or secondary outcomes (any AKI and serum creatinine/cystatin C values at days 0, 7, 9, and 14). At 22-26 months of cGA, 16% of the cohort had an estimated glomerular filtration rate (eGFR) <90 mL/min/1.73 m², 35.8% had urine albumin/creatinine ratio >30 mg/g, 23% had a systolic blood pressure (SBP) >95th percentile for age, and 40% had a diastolic blood pressure (DBP) >95th percentile for age. SBP >90th percentile occurred less often among recipients of erythropoietin (P < .04). This association remained even after controlling for gestational age, site, and sibship (aOR 0.6; 95% CI 0.39-0.92). We did not find statistically significant differences between treatment groups in eGFR, albumin/creatinine ratio, rates of SBP >95th percentile, or DBP >90th or >95th percentiles at the 2 year follow-up visit.

CONCLUSIONS

ELGANs have high rates of in-hospital AKI and kidney-related problems at 22-26 months of cGA. Recombinant erythropoietin may protect ELGANs against long-term elevated SBP but does not appear to protect from AKI, low eGFR, albuminuria, or elevated DBP at 22-26 months of cGA.

Novel erythropoietin-based therapeutic candidates with extra N-glycan sites that block hematopoiesis but preserve neuroplasticity

Neurological disorders affect millions of people causing behavior-cognitive disabilities. Nowadays they have no effective treatment. Human erythropoietin (hEPO) has been clinically used because of its neurotrophic and cytoprotective properties. However, the erythropoietic activity (EA) should be considered as a side effect. Some analogs like non-sialylated EPO, carbamylated EPO, or EPO peptides have been developed showing different weaknesses: erythropoiesis preservation, low stability, potential immunogenicity, or fast clearance. Herein, we used a novel strategy that blocks the EA but preserves hEPO neurobiological actions. N-glycoengineering was accomplished to add a new glycosylation site within the hEPO sequence responsible for its EA. hEPO-derivatives were produced by CHO.K1 cells, affinity-purified and functionally analyzed studying their in vitro and in vivo EA, their in vitro neuronal plasticity in hippocampal neurons and their neuroprotective action by rescuing hippocampal neurons from apoptosis. Muteins Mut 45_47 (K45 > N45 + N47 > T47), Mut 104 (S104 > N104), and Mut 151_153 (G151 > N151 + K153 > T153) lost their EA but preserved their neuroprotection activity and enhanced neuroplasticity more efficiently than hEPO. Interestingly, Mut 45_47 resulted in a promising candidate to explore as neurotherapeutic considering not only its biopotency but also its pharmacokinetic potential due to the hyperglycosylation.

Cancer Related Anemia: An Integrated Multitarget Approach and Lifestyle Interventions

Cancer is often accompanied by worsening of the patient's iron profile, and the resulting anemia could be a factor that negatively impacts antineoplastic treatment efficacy and patient survival. The first line of therapy is usually based on oral or intravenous iron supplementation; however, many patients remain anemic and do not respond. The key might lie in the pathogenesis of the anemia itself. Cancer-related anemia (CRA) is characterized by a decreased circulating serum iron concentration and transferrin saturation despite ample iron stores, pointing to a more complex problem related to iron homeostatic regulation and additional factors such as chronic inflammatory status. This review explores our current understanding of iron homeostasis in cancer, shedding light on the modulatory role of hepcidin in intestinal iron absorption, iron recycling, mobilization from liver deposits, and inducible regulators by infections and inflammation. The underlying relationship between CRA and systemic low-grade inflammation will be discussed, and an integrated multitarget approach based on nutrition and exercise to improve iron utilization by reducing low-grade inflammation, modulating the immune response, and supporting antioxidant mechanisms will also be proposed. Indeed, a Mediterranean-based diet, nutritional supplements and exercise are suggested as potential individualized strategies and as a complementary approach to conventional CRA therapy.

Erythropoietin Plays a Protective Role in Submandibular Gland Hypofunction Induced by Irradiation

PURPOSE

This study aims to explore the radioprotective effects of recombinant human erythropoietin (rhEPO) on rats' submandibular gland hypofunction induced by irradiation (IR).

MATERIALS AND METHODS

Thirty rats were divided into 3 groups: 1) control group, 2) IR group, and 3) IR + rhEPO group. The IR group and IR + rhEPO group received a single dose of 15 Grays (Gy) (0.98 Gy/min), plus, the IR + rhEPO group also received subcutaneous administration of rhEPO at a dose of 3,000 IU/kg body weight 3 days before irradiation and then repeated every 24 hours for the first 2 weeks after irradiation. Immunohistochemistry analysis to erythropoietin receptor was performed to detect the levels of erythropoietin receptor in submandibular glands with or without radiation. Ninety days after irradiation, the salivary flow rates were assessed, and the submandibular gland of every rat was subjected to hematoxylin and eosin staining and immunohistochemical staining with antiaquaporin 5 and anti-proliferating cell nuclear antigen antibodies. Apoptosis was examined by the terminal deoxynucleotidyl transferase biotin-dUDP nick end-labeling assay. In addition, to examine the protective role of rhEPO on human submandibular gland cells, the apoptotic and proliferation rate of cells under a radiation dose of 8 Gy was detected. One-way analysis of variance was carried out to analyze the results of each group, and the P value was set at 0.05.

RESULTS

Erythropoietin receptor was expressed in the submandibular glands at a low level under normal conditions but upregulated after irradiation. rhEPO administration remarkably alleviated gland atrophy, increased salivary flow rates with upregulation of aquaporin-5 compared with the IR group. In addition, fewer apoptotic cells and more proliferative cells were observed in the IR + rhEPO group compared with the IR group, both in vivo and in vitro.

CONCLUSIONS

rhEPO administration may be a useful countermeasure to mitigate submandibular gland hypofunction after therapeutic radiation exposure.

Non-hematopoietic erythropoietin-derived peptides for atheroprotection and treatment of cardiovascular diseases

Relevance: Cardiovascular diseases continue to be the leading cause of premature adult death.

Lipid profile and atherogenesis: Dislipidaemia leads to subsequent lipid accumulation and migration of immunocompetent cells into the vessel intima. Macrophages accumulate cholesterol forming foam cells – the morphological substrate of atherosclerosis in its initial stage.

Inflammation and atherogenesis: Pro-inflammatory factors provoke oxidative stress, vascular wall damage and foam cells formation.

Endothelial and mitochondrial dysfunction in the development of atherosclerosis: Endothelial mitochondria are some of the organelles most sensitive to oxidative stress. Damaged mitochondria produce excess superoxide and H2O2, which are the main factors of intracellular damage, further increasing endothelial dysfunction.

Short non-hematopoietic erythropoietin-based peptides as innovative atheroprotectors: Research in recent decades has shown that erythropoietin has a high cytoprotective activity, which is mainly associated with exposure to the mitochondrial link and has been confirmed in various experimental models. There is also a short-chain derivative, the 11-amino acid pyroglutamate helix B surface peptide (PHBSP), which selectively binds to the erythropoietin heterodymic receptor and reproduces its cytoprotective properties. This indicates the promising use of short-chain derivatives of erythropoietin for the treatment and prevention of atherosclerotic vascular injury. In the future, it is planned to study the PHBSP derivatives, the modification of which consists in adding RGD and PGP tripeptides with antiaggregant properties to the original 11-member peptide.

Erythropoietin regulation of red blood cell production: from bench to bedside and back

More than 50 years of efforts to identify the major cytokine responsible for red blood cell (RBC) production (erythropoiesis) led to the identification of erythropoietin (EPO) in 1977 and its receptor (EPOR) in 1989, followed by three decades of rich scientific discovery. We now know that an elaborate oxygen-sensing mechanism regulates the production of EPO, which in turn promotes the maturation and survival of erythroid progenitors. Engagement of the EPOR by EPO activates three interconnected signaling pathways that drive RBC production via diverse downstream effectors and simultaneously trigger negative feedback loops to suppress signaling activity. Together, the finely tuned mechanisms that drive endogenous EPO production and facilitate its downstream activities have evolved to maintain RBC levels in a narrow physiological range and to respond rapidly to erythropoietic stresses such as hypoxia or blood loss. Examination of these pathways has elucidated the genetics of numerous inherited and acquired disorders associated with deficient or excessive RBC production and generated valuable drugs to treat anemia, including recombinant human EPO and more recently the prolyl hydroxylase inhibitors, which act partly by stimulating endogenous EPO synthesis. Ongoing structure-function studies of the EPOR and its essential partner, tyrosine kinase JAK2, suggest that it may be possible to generate new "designer" drugs that control selected subsets of cytokine receptor activities for therapeutic manipulation of hematopoiesis and treatment of blood cancers.

The multiple organs insult and compensation mechanism in mice exposed to hypobaric hypoxia

This study was first and systematically conducted to evaluate the hypoxia response of the brain, heart, lung, liver, and kidney of mice exposed to an animal hypobaric chamber. First, we examined the pathological damage of the above tissues by Hematoxylin & eosin (H&E) staining. Secondly, biochemical assays were used to detect oxidative stress indicators such as superoxide dismutase (SOD), malondialdehyde (MDA), reduced glutathione (GSH), and oxidized glutathione (GSSG). Finally, the hypoxia compensation mechanism of tissues was evaluated by expression levels of hypoxia-inducible factor 1 alpha (HIF-1α), erythropoietin (EPO), and vascular endothelial growth factor (VEGF). During the experiment, the mice lost weight gradually on the first 3 days, and then, the weight loss tended to remain stable, and feed consumption showed the inverse trend. H&E staining results showed that there were sparse and atrophic neurons and dissolved chromatin in the hypoxia group. And hyperemia occurred in the myocardium, lung, liver, and kidney. Meanwhile, hypoxia stimulated the enlargement of myocardial space, the infiltration of inflammatory cells in lung tissue, the swelling of epithelial cells in hepatic lobules and renal tubules, and the separation of basal cells. Moreover, hypoxia markedly inhibited the activity of SOD and GSH and exacerbated the levels of MDA and GSSG in the serum and five organs. In addition, hypoxia induced the expression of HIF-1α, EPO, and VEGF in five organs. These results suggest hypoxia leads to oxidative damage and compensation mechanism of the brain, heart, lung, liver, and kidney in varying degrees of mice.

Erythropoietin as a Neuroprotective Molecule: An Overview of Its Therapeutic Potential in Neurodegenerative Diseases

Erythropoietin (EPO) is a cytokine mainly induced in hypoxia conditions. Its major production site is the kidney. EPO primarily acts on the erythroid progenitor cells in the bone marrow. More and more studies are highlighting its secondary functions, with a crucial focus on its role in the central nervous system. Here, EPO may interact with up to four distinct isoforms of its receptor (erythropoietin receptor [EPOR]), activating different signaling cascades with roles in neuroprotection and neurogenesis. Indeed, the EPO/EPOR axis has been widely studied in the neurodegenerative diseases field. Its potential therapeutic effects have been evaluated in multiple disorders, such as Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, spinal cord injury, as well as brain ischemia, hypoxia, and hyperoxia. EPO is showing great promise by counteracting secondary neuroinflammatory processes, reactive oxygen species imbalance, and cell death in these diseases. Multiple studies have been performed both in vitro and in vivo, characterizing the mechanisms through which EPO exerts its neurotrophic action. In some cases, clinical trials involving EPO have been performed, highlighting its therapeutic potential. Together, all these works indicate the potential beneficial effects of EPO.

An engineered non-erythropoietic erythropoietin-derived peptide, ARA290, attenuates doxorubicin induced genotoxicity and oxidative stress

Erythropoietin (EPO) applies anti-inflammatory, anti-apoptotic, anti-oxidant and cytoprotective effects besides its hematopoietic action. A nonhematopoietic peptide engineered from EPO, ARA 290, interacts selectively with the innate repair receptor and has similar possessions. ARA290 mediates tissue protection without hematopoietic side-effects of EPO which limit its clinical application. Doxorubicin (DOX) is the broad-spectrum chemotherapeutic agent, but its use is limited by the development of nonspecific toxicity on noncancerous tissues especially in cardiac cells. Mechanisms behind the DOX-induced toxicities are enhanced level of oxidative damage, inflammation and apoptosis. In the present study, we have investigated whether ARA290 acts as a chemoprotective agent modulating the cytotoxicity, genotoxicity and oxidative stress induced in vitro by DOX. The genoprotective effect of ARA290 on DOX-induced toxicity in three cell line (HepG2, HGF & Stem cell) were assessed. Cells were treated with ARA290 (50-400 nM) and DOX (1 μM) in pretreatment condition. Cytotoxicity was evaluated using the MTT assay, genoprotective effect of ARA290 were evaluated using the micronucleus test and comet assay. AR290 significantly reduced the percentage of DNA in tail and the frequency of micronuclei induced by DOX. Besides, DOX impaired anti-oxidant defense enzyme activities and induced inflammation and apoptotic cell death. ARA290 markedly attenuated DOX induced oxidative stress and protected against DOX induced inflammation and apoptotic cell death. This result proposes that ARA290 can act as a protective agent, reducing DOX-induced DNA damage and oxidative stress, and it is possible that this protection could also extend to cardiac cells.

Does recombinant human erythropoietin administration in critically ill COVID-19 patients have miraculous therapeutic effects?

An 80‐year‐old man with multiple comorbidities presented to the emergency department with tachypnea, tachycardia, fever, and critically low O₂ saturation and definitive chest computerized tomography scan findings in favor of COVID‐19 and positive PCR results in 48 hours. He received antiviral treatment plus recombinant human erythropoietin (rhEPO) due to his severe anemia. After 7 days of treatment, he was discharged with miraculous improvement in his symptoms and hemoglobin level. We concluded that rhEPO could attenuate respiratory distress syndrome and confront the severe acute respiratory syndrome coronavirus 2 virus through multiple mechanisms including cytokine modulation, antiapoptotic effects, leukocyte release from bone marrow, and iron redistribution away from the intracellular virus.

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Recombinant human erythropoietin can rapidly correct anemia and symptoms associated with COVID‐19

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Through cytokine modulation, rhEPO exerts its cytoprotective and anti‐apoptotic effects in COVID pneumonia.

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rhEPO takes iron away from intracellular virus into the bone marrow, undermining the viral enzymatic requirements.

Normobaric intermittent hypoxic training regulates microglia phenotype and enhances phagocytic activity

IMPACT STATEMENT

The effects of intermittent hypoxic training or conditioning on many pathological conditions have been widely investigated. One of the pathological conditions dealt with intermittent hypoxic training is ischemic stroke. Well-known mechanisms of intermittent hypoxia-induced protection are related to increased energy metabolism and the enhanced antioxidant effects. In the last decades, the role of microglia in the progress of ischemic stroke-related brain damage has been focused. The dual-edge function of microglia indicates that the microglia-mediated inflammatory response is definitely beneficial in the early stage of ischemic stroke, but long-term activation of microglia is rather detrimental during the recovery process. The effect of IHT on microglia polarization is not investigated. This study focused on whether IHT regulates the polarization of microglia without dampening its classic phagocytic function. This study will provide pivotal information regarding the effects of IHT on the long-term effects on the recovery process from ischemic stroke.

Recombinant Erythropoietin Provides Protection against Renal Fibrosis in Adenine-Induced Chronic Kidney Disease

Chronic kidney disease (CKD) causes anemia by renal damage. In CKD, the kidney is submitted to hypoxia, persistent inflammation, leading to fibrosis and permanent loss of renal function. Human recombinant erythropoietin (rEPO) has been widely used to treat CKD-associated anemia and is known to possess organ-protective properties that are independent from its well-established hematopoietic effects. Nonhematopoietic effects of EPO are mediated by an alternative receptor that is proposed to consist of a heterocomplex between the erythropoietin receptor (EPOR) and the beta common receptor (βcR). The present study explored the effects of rEPO to prevent renal fibrosis in adenine-induced chronic kidney disease (Ad-CKD) and their association with the expression of the heterodimer EPOR/βcR. Male Wistar rats were randomized to control group (CTL), adenine-fed rats (Ad-CKD), and Ad-CKD with treatment of rEPO (1050 IU/kg, once weekly for 4 weeks). Ad-CKD rats exhibited anemia, uremia, decreased renal function, increased infiltration of inflammatory cells, tubular atrophy, and fibrosis. rEPO treatment not only corrected anemia but reduced uremia and partially improved renal function as well. In addition, we observed that rEPO diminishes tubular injury, prevents fibrosis deposition, and induces the EPOR/βcR heteroreceptor. The findings may explain the extrahematopoietic effects of rEPO in CKD and provide new strategies for the treatment of renal fibrosis in CKD.

Myokines as biomarkers of frailty and cardiovascular disease risk in females

Frailty is a risk factor for cardiovascular disease (CVD). Biomarkers have the potential to detect the early stages of frailty, such as pre-frailty. Myokines may act as biomarkers of frailty-related disease progression, as a decline in muscle health is a hallmark of the frailty phenotype. This study is a secondary analysis of 104 females 55 years of age or older with no previous history of CVD. Differences in systemic myokine concentrations based on frailty status and CVD risk profile were examined using a case-control design. Propensity matching identified two sets of 26 pairs with pre-frailty as the exposure variable in low or elevated CVD risk groups for a total 104 female participants. Frailty was assessed using the Fried Criteria (FC) and CVD risk was assessed using the Framingham Risk Score (FRS). Factorial ANOVA compared the main effects of frailty, CVD risk, and their interaction on the concentrations of 15 myokines. Differences were found when comparing elevated CVD risk status with low for the concentrations of EPO (384.76 ± 1046.07 vs. 206.63 ± 284.61 pg/mL, p = .001), FABP3 (2772.61 ± 3297.86 vs. 1693.31 ± 1019.34 pg/mL, p = .017), FGF21 (193.17 ± 521.09 vs. 70.18 ± 139.51 pg/mL, p = .010), IL-6 (1.73 ± 4.97 vs. 0.52 ± 0.89 pg/mL, p = .023), and IL-15 (2.62 ± 10.56 vs. 0.92 ± 1.25 pg/mL, p = .022). Pre-frail females had lower concentrations of fractalkine compared to robust (27.04 ± 20.60 vs. 103.62 ± 315.45 pg/mL, p = .004). Interaction effects between frailty status and CVD risk for FGF21 and OSM were identified. In elevated CVD risk, pre-frail females, concentrations of FGF21 and OSM were lower than that of elevated CVD risk, robust females (69.10 ± 62.86 vs. 317.24 ± 719.69, p = .011; 1.73 ± 2.32 vs. 24.43 ± 69.21, p = .018, respectively). These data identified specific biomarkers of CVD risk and biomarkers of frailty that are exacerbated with CVD risk.

Erythropoietin Alleviates Burn-induced Muscle Wasting

Background: Burn injury induces long-term skeletal muscle pathology. We hypothesized EPO could attenuate burn-induced muscle fiber atrophy. Methods: Rats were allocated into four groups: a sham burn group, an untreated burn group subjected to third degree hind paw burn, and two burn groups treated with weekly or daily EPO for four weeks. Gastrocnemius muscle was analyzed at four weeks post-burn. Results: EPO attenuated the reduction of mean myofiber cross-sectional area post-burn and the level of the protective effect was no significant difference between two EPO-treated groups (p=0.784). Furthermore, EPO decreased the expression of atrophy-related ubiquitin ligase, atrogin-1, which was up-regulated in response to burn. Compared to untreated burn rats, those receiving weekly or daily EPO groups had less cell apoptosis by TUNEL assay. EPO decreased the expression of cleaved caspase 3 (key factor in the caspase-dependent pathway) and apoptosis-inducing factor (implicated in the caspase-independent pathway) after burn. Furthermore, EPO alleviated connective tissue overproduction following burn via transforming growth factor beta 1-Smad2/3 pathway. Daily EPO group caused significant erythrocytosis compared with untreated burn group but not weekly EPO group. Conclusion: EPO therapy attenuated skeletal muscle apoptosis and fibrosis at four weeks post-burn. Weekly EPO may be a safe and effective option in muscle wasting post-burn.

Human recombinant erythropoietin improves motor function in rats with spinal cord compression-induced cervical myelopathy

Objective

Erythropoietin (EPO) is a clinically available hematopoietic cytokine. EPO has shown beneficial effects in the context of spinal cord injury and other neurological conditions. The aim of this study was to evaluate the effect of EPO on a rat model of spinal cord compression-induced cervical myelopathy and to explore the possibility of its use as a pharmacological treatment.

Methods

To develop the compression-induced cervical myelopathy model, an expandable polymer was implanted under the C5-C6 laminae of rats. EPO administration was started 8 weeks after implantation of a polymer. Motor function of rotarod performance and grip strength was measured after surgery, and motor neurons were evaluated with H-E, NeuN and choline acetyltransferase staining. Apoptotic cell death was assessed with TUNEL and Caspase-3 staining. The 5HT, GAP-43 and synaptophysin were evaluated to investigate the protection and plasticity of axons. Amyloid beta precursor protein (APP) was assessed to evaluate axonal injury.

To assess transfer of EPO into spinal cord tissue, the EPO levels in spinal cord tissue were measured with an ELISA for each group after subcutaneous injection of EPO.

Results

High-dose EPO maintained motor function in the compression groups. EPO significantly prevented the loss of motor neurons and significantly decreased neuronal apoptotic cells. Expression of 5HT and synaptophysin was significantly preserved in the EPO group. APP expression was partly reduced in the EPO group. The EPO levels in spinal cord tissue were significantly higher in the high-dose EPO group than other groups.

Conclusion

EPO improved motor function in rats with compression-induced cervical myelopathy. EPO suppressed neuronal cell apoptosis, protected motor neurons, and induced axonal protection and plasticity. The neuroprotective effects were produced following transfer of EPO into the spinal cord tissue. These findings suggest that EPO has high potential as a treatment for degenerative cervical myelopathy.

Neuronanotechnology for brain regeneration

Identifying and harnessing regenerative pathways while suppressing the growth-inhibiting processes of the biological response to injury is the central goal of stimulating neurogenesis after central nervous system (CNS) injury. However, due to the complexity of the mature CNS involving a plethora of cellular pathways and extracellular cues, as well as difficulties in accessibility without highly invasive procedures, clinical successes of regenerative medicine for CNS injuries have been extremely limited. Current interventions primarily focus on stabilization and mitigation of further neuronal death rather than direct stimulation of neurogenesis. In the past few decades, nanotechnology has offered substantial innovations to the field of regenerative medicine. Their nanoscale features allow for the fine tuning of biological interactions for enhancing drug delivery and stimulating cellular processes. This review gives an overview of nanotechnology applications in CNS regeneration organized according to cellular and extracellular targets and discuss future directions for the field.

Recombinant Human Erythropoietin Restrains Oxidative Stress in Streptozotocin-induced Diabetic Rats Exposed to Renal Ischemia Reperfusion Injury

BACKGROUND

Renal ischemia/reperfusion (I/R) injury (RI/RI) is a common complication of diabetes mellitus (DM) in surgical practice. Oxidative stress plays a crucial role in this process. Recombinant human erythropoietin (rhEPO) is usually used to treat anemia resulting from several diseases. However, the functional involvement of rhEPO in diabetic RI/RI remains unclear. The present study was intended to investigate the antioxidant role of rhEPO on RI/RI in DM rats.

METHODS

The bilateral renal arteries and veins of streptozotocin-induced diabetic rats were subjected to 45 minutes of ischemia followed by 1, 6, and 24 hours of reperfusion with or without rhEPO pretreatment at the beginning of an I/R procedure. The renal tissue pathomorphology, renal function, oxidative stress, and inflammatory response were evaluated by detection of a series of indices by hematoxylin-eosin staining, commercial kits, enzyme-linked immunosorbent assay, and spectrophotofluorometry, respectively.

RESULTS

Compared to the I/R group, renal function was significantly advanced in the erythropoietin group, whose subjects were also subjected to renal tissue injury, oxidative stress, and inflammation.

CONCLUSION

These results suggest that rhEPO preconditioning can attenuate diabetic RI/RI through regulating endogenous antioxidant activity.

Neuroprotective effects of EpoL against oxidative stress induced by soluble oligomers of Aβ peptide

Erythropoietin is a glycoproteic hormone that regulates hematopoiesis by acting on its specific receptor (EpoR). The expression of EpoR in the central nervous system (CNS) suggests a role for this hormone in the brain. Recently, we developed a new Epo variant without hematopoietic activity called EpoL, which showed marked neuroprotective effects against oxidative stress in brain ischemia related models. In this study, we have evaluated the neuroprotective effects of EpoL against oxidative stress induced by chronic treatment with Aβ. Our results show that EpoL was neuroprotective against Aβ-induced toxicity by a mechanism that implicates EpoR, reduction in reactive oxygen species, and reduction in astrogliosis. Furthermore, EpoL treatment improved calcium handling and SV2 levels. Interestingly, the neuroprotective effect of EpoL against oxidative stress induced by chronic Aβ treatment was achieved at a concentration 10 times lower than that of Epo. In conclusion, EpoL, a new variant of Epo without hematopoietic activity, is of potential interest for the treatment of diseases related to oxidative stress in the CNS such as Alzheimer disease.

Flow Mediated Skin Fluorescence technique reveals remarkable effect of age on microcirculation and metabolic regulation in type 1 diabetes

STUDY DESCRIPTION

Flow Mediated Skin Fluorescence (FMSF) is a novel technique for non-invasive evaluation of the microcirculation and metabolic regulation. This study describes the diagnostic potential of FMSF for type 1 diabetes (DM1).

STUDY POPULATION

All study participants, in both the control (n = 31) and DM1 (n = 40) groups, were between the ages of 30-49 y. The patients in the DM1 group had all been suffering from diabetes for at least 10 y.

RESULTS

The parameters HR_index, HR_max and MR inversely correlate with age and BMI. An unidentified compensatory effect was observed among the younger members of the DM1 group. The majority of DM1 patients with HR_index < 8% showed signs of dysfunctional metabolic regulation.

CONCLUSION

FMSF appears to be an extremely useful technique for monitoring diabetic patients over time, enabling early diagnosis of potentially dysfunctional microcirculation and metabolic regulation.

The Recombinant Human Erythropoietin Administered in Neonatal Rats After Excitotoxic Damage Induces Molecular Changes in the Hippocampus

In vitro and in vivo experimental evidence has contributed important knowledge regarding the antiapoptotic effect mediated by EPO signaling in the damaged brain, particularly through different models with a hypoxic component. However, little emphasis has been placed on the effectiveness of rhEPO administration against cellular alterations caused by in vivo excitotoxicity or on the molecular mechanism that regulates this effect. In this study, we investigated the effects of a single dose of rhEPO on hippocampal damage induced by subcutaneous application of monosodium glutamate (MSG) on postnatal days 1, 3, 5 and 7 in neonatal rats. We found that a dose of 1000 IU/kg of b.w. administered 24 h after MSG had the greatest protective effect. In addition, we analyzed changes in gene expression, particularly in 3 key molecules involved in EPO-mediated signaling (EPO, EPOR and βcR). We observed that the expression of EPO and EPOR was differentially modified at both the mRNA and protein levels under the evaluated conditions, while the expression of the βcR gene was substantially increased. Our data suggest that a low dose of rhEPO is sufficient to induce cellular protection under these experimental conditions and that the molecular changes could be a positive feedback mechanism, mediated by reactive astrocytes in association with in vivo neuroprotective mechanisms.

Erythropoietin in Critical Illness and Trauma

Erythropoietin (EPO) is a 34kD pleiotropic cytokine that was first identified as being essential for red blood cell (RBC) production. It is now recognized however that EPO is produced by many tissues. It plays a key role in the modulation of the response to injury, inflammation, and tissue hypoxia via the inhibition of apoptosis. Large clinical trials in the critically ill failed to demonstrate a role for EPO as an RBC transfusion sparing agent; however, improved clinical outcomes, attributable to EPO role in tissue protection are observed in critically ill trauma patients. Further research to confirm or refute these observations is required.

Robust increases in erythropoietin production by the hypoxic fetus is a response to protect the brain and other vital organs

Fetal erythropoietin (EPO), in addition to regulating erythropoiesis, has also tissue-protective properties based on its anti-inflammatory, anti-apoptotic, antioxidant, and neurotrophic effects. Notably, EPO concentrations needed for tissue protection are 100-1000 times higher than concentrations needed for regulating erythropoiesis. This dual effect of EPO is based on EPO-receptor (EPO-R) isoforms, which differ structurally and functionally. We hypothesize in this Integrated Mechanism Review that during severe fetal hypoxia the observed, but poorly understood, marked increases of fetal plasma EPO concentrations occur to protect the brain, heart, and other vital fetal organs. We further hypothesize that the concurrent marked increases of EPO in the amniotic fluid during fetal hypoxia, occur to protect newborn infants from necrotizing enterocolitis. This review presents experimental and clinical evidence in support of these hypotheses and points out unknown or poorly understood functions of EPO in the fetus. If these novel hypotheses are correct, the importance of fetal EPO as an antenatal hypoxia biomarker will become apparent. It will also likely point the way to important diagnostic and therapeutic fetal and neonatal interventions.

GSK3β: a plausible mechanism of cognitive and hippocampal changes induced by erythropoietin treatment in mood disorders?

Mood disorders are associated with significant psychosocial and occupational disability. It is estimated that major depressive disorder (MDD) will become the second leading cause of disability worldwide by 2020. Existing pharmacological and psychological treatments are limited for targeting cognitive dysfunctions in mood disorders. However, growing evidence from human and animal studies has shown that treatment with erythropoietin (EPO) can improve cognitive function. A recent study involving EPO-treated patients with mood disorders showed that the neural basis for their cognitive improvements appeared to involve an increase in hippocampal volume. Molecular mechanisms underlying hippocampal changes have been proposed, including the activation of anti-apoptotic, antioxidant, pro-survival and anti-inflammatory signalling pathways. The aim of this review is to describe the potential importance of glycogen synthase kinase 3-beta (GSK3β) as a multi-potent molecular mechanism of EPO-induced hippocampal volume change in mood disorder patients. We first examine published associations between EPO administration, mood disorders, cognition and hippocampal volume. We then highlight evidence suggesting that GSK3β influences hippocampal volume in MDD patients, and how this could assist with targeting more precise treatments particularly for cognitive deficits in patients with mood disorders. We conclude by suggesting how this developing area of research can be further advanced, such as using pharmacogenetic studies of EPO treatment in patients with mood disorders.

Pathogenesis and Treatment Options of Cancer Related Anemia: Perspective for a Targeted Mechanism-Based Approach

Cancer-related anemia (CRA) is a common sign occurring in more than 30% of cancer patients at diagnosis before the initiation of antineoplastic therapy. CRA has a relevant influence on survival, disease progression, treatment efficacy, and the patients' quality of life. It is more often detected in patients with advanced stage disease, where it represents a specific symptom of the neoplastic disease, as a consequence of chronic inflammation. In fact, CRA is characterized by biological and hematologic features that resemble those described in anemia associated to chronic inflammatory disease. Proinflammatory cytokine, mainly IL-6, which are released by both tumor and immune cells, play a pivotal action in CRA etiopathogenesis: they promote alterations in erythroid progenitor proliferation, erythropoietin (EPO) production, survival of circulating erythrocytes, iron balance, redox status, and energy metabolism, all of which can lead to anemia. The discovery of hepcidin allowed a greater knowledge of the relationships between immune cells, iron metabolism, and anemia in chronic inflammatory diseases. Additionally, chronic inflammation influences a compromised nutritional status, which in turn might induce or contribute to CRA. In the present review we examine the multifactorial pathogenesis of CRA discussing the main and novel mechanisms by which immune, nutritional, and metabolic components affect its onset and severity. Moreover, we analyze the status of the art and the perspective for the treatment of CRA. Notably, despite the high incidence and clinical relevance of CRA, controlled clinical studies testing the most appropriate treatment for CRA are scarce, and its management in clinical practice remains challenging. The present review may be useful to indicate the development of an effective approach based on a detailed assessment of all factors potentially involved in the pathogenesis of CRA. This mechanism-based approach is essential for clinicians to plan a safe, targeted, and successful therapy, thereby promoting a relevant amelioration of patients' quality of life.

Synergistic Reduction of Apoptosis With Diazoxide and Erythropoietin in Spinal Cord Ischemic Injury

BACKGROUND

Paraplegia remains a devastating complication of thoracoabdominal aortic intervention. Metabolic stress induces expression of beta common receptor subunit of erythropoietin (EPO) receptor (βcR) to exert a neuroprotective effect in spinal cord ischemia reperfusion injury (SCIR). Diazoxide (DZ) has been shown to induce ischemic tolerance. We previously reported that DZ upregulated βcR expression and enhanced the neuroprotective effects of EPO through the upregulation of βcR. We hypothesize that βcR expression induced by DZ before ischemia amplifies the antiapoptotic effects of EPO in a murine model of SCIR.

METHODS

Experimental groups included phosphate-buffered saline (PBS) pretreatment + PBS immediately before the operation, PBS+EPO, DZ+PBS, DZ+EPO, and sham. Spinal cord ischemia was induced by a 4-minute thoracic aortic cross-clamp. Functional scoring (Basso Mouse Score) was done at 12-hour intervals for 48 hours. Spinal cords were harvested for histologic analysis, and antiapoptotic factors (caspase 3, 8, and 9, B-cell lymphoma-2, and neuroglobin) were evaluated by Western blot analysis.

RESULTS

The motor function of DZ+EPO group was significantly preserved compared with all other groups. The levels of cleaved caspase 8 and 3 in DZ+EPO were significantly lower than in the other groups. Mice treated with DZ+EPO had significantly fewer terminal deoxynucleotide transferase-mediated deoxy uridine triphosphate nick-end labeling-positive cells than other groups.

CONCLUSIONS

Optimized upregulation of βcR by DZ can increase the extrinsic antiapoptotic effects of EPO. Better understanding of this synergetic mechanism may serve to help prevent ischemic complications caused by aortic intervention.

Protein Carbamylation in Chronic Kidney Disease and Dialysis

Protein carbamylation is a nonenzymatic posttranslational protein modification that can be driven, in part, by exposure to urea's dissociation product, cyanate. In humans, when kidney function is impaired and urea accumulates, systemic protein carbamylation levels increase. Additional mediators of protein carbamylation have been identified including inflammation, diet, smoking, circulating free amino acid levels, and environmental exposures. Carbamylation reactions on proteins are capable of irreversibly changing protein charge, structure, and function, resulting in pathologic molecular and cellular responses. Carbamylation has been mechanistically linked to the biochemical pathways implicated in atherosclerosis, dysfunctional erythropoiesis, kidney fibrosis, autoimmunity, and other pathological domains highly relevant to patients with chronic kidney disease. In this review, we describe the biochemical impact of carbamylation on human proteins, the mechanistic role carbamylation can have on clinical outcomes in kidney disease, the clinical association studies of carbamylation in chronic kidney disease, including patients on dialysis, and the promise of therapies aimed at reducing carbamylation burden in this vulnerable patient population.

Upregulation of klotho and erythropoietin contributes to the neuroprotection induced by curcumin-loaded nanoparticles in experimental model of chronic epilepsy

Klotho, which is a life extension factor, and erythropoietin (EPO) have been introduced as effective neuroprotective factors in several neurological disorders. The present study is an attempt to examine the potential role of klotho and EPO in therapeutic effect of curcumin-loaded nanoparticles (NPs) in pentylenetetrazol (PTZ)-induced kindling model. In order to induce the kindling model, PTZ was administrated intraperitoneally (i.p.) at dose of 36.5 mg/kg every other day for 20 days. Male NMRI mice received pre-treatment of free curcumin or curcumin-loaded NPs (12.5 mg/kg, i.p.) 10 days before PTZ injection and this was continued until 1 h before each PTZ injection. Immunostaining against NeuN, as a marker of neuronal maturation, and EPO was performed on hippocampal brain sections. Quantitative real time polymerase chain reaction (qRT-PCR) was conducted to assess the expression levels of tumor necrosis factor-α (TNF-α), klotho and EPO in the hippocampus. Immunostaining data indicated that treatment with curcumin-loaded NPs significantly alleviates the neuronal cell death in PTZ receiving animals. Curcumin-loaded NPs effectively upregulated the levels of EPO and klotho in PTZ receiving animals. Furthermore, mRNA level of TNF-α was considerably reduced in animals undergone curcumin-loaded NPs treatment. Overall, the results of this study suggest that downregulation of TNF-α and consequent upregulation of klotho and EPO might contribute to the neuroprotective effect of curcumin-loaded NPs in experimental model of epilepsy.

Reduced Hypoxia-Related Genes in Porcine Limbs in Ex Vivo Hypothermic Perfusion Versus Cold Storage

BACKGROUND

Ischemia-reperfusion injury remains the major limiting factor for limb replantation and transplantation. Static cold storage (SCS) on ice currently represents the standard mode of preservation but is limited to 6 h of duration. Ex vivo machine perfusion has evolved as a potential alternative to safely extend the duration of ex vivo preservation by providing continuous supply of oxygen and nutrients. This study aims to evaluate underlying molecular mechanisms of both preservation modalities.

METHODS

We assessed molecular changes in amputated porcine forelimbs stored on ice at 4°C for 2 h (n = 2) and limbs perfused with Perfadex solution at 10°C for 2 h (n = 3) or 12 h (n = 3) before replantation. Muscle biopsies were examined for histological changes and gene expression levels using H&E staining and a hypoxia-related PCR gene array, respectively.

RESULTS

Histology revealed only minor differences between the ice (SCS) and perfusion groups after 2 h of preservation, with decreased muscle fiber disruption in the perfusion groups compared with the ice (SCS) group. Perfused limbs demonstrated downregulation of genes coding for glycolytic pathways and glucose transporters after 2 h and 12 h when compared with SCS after 2 h. Similarly, genes that induce angiogenesis and those that are activated on DNA damage were downregulated in both perfusion groups as compared with SCS.

CONCLUSIONS

Perfusion of porcine limbs resulted in less activation of hypoxia-related gene families when compared with SCS. This may indicate a state more closely resembling physiological conditions during perfusion and potentially limiting ischemic injury. Our study confirms ex vivo perfusion for up to 12 h as a viable alternative for preservation of vascularized composite tissues.