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

A Novel Neuroprotective Derived Peptide of Erythropoietin Improved Cognitive Function in Vascular Dementia Mice

The effective therapeutics for vascular dementia are still lacking. Here, we designed a novel derived peptide of erythropoietin-DEPO and evaluated its safety, erythropoiesis effect, and neuroprotective effects in mice of vascular dementia. For evaluating the safety and erythropoiesis, DEPO was injected into naive C57BL6 mice (n = 5) for 4-8 weeks, and venous blood was collected at 1, 2, and 4 weeks after DEPO treatment. Neuroprotective effects of DEPO were studied in both cultured neurons and bilateral common carotid artery stenosis (BCAS) mice (n = 10/group). After 4-week DEPO administration, neurobehavioral tests and histology were applied to evaluate cognitive function and brain tissue damage of mice, respectively. Molecule docking, western blotting, pharmacological or genetic interference with EPOR, and JAK/STAT/AKT pathway were used to determine the mechanism of neuroprotective effects of DEPO. DEPO did not increase the hemoglobin concentration or red blood cell number in mice after 4-week treatment compared to the Vehicle group (p > 0.05). DEPO treatment alleviated spatial reference memory impairment and the anxiety level in mice (p < 0.05). Both gray and white matter injuries were significantly alleviated by DEPO treatment. DEPO activated JAK/STAT pathway in cultured neurons and protected neurons against chronic ischemia (p < 0.05). Pharmacological or genetic interference with JAK2 signaling or EPOR inhibited the pro-survival effect of DEPO on chronic ischemia neurons (p < 0.05). DEPO is a novel safe erythropoietin-derived peptide and exerted its neuroprotective effects in vascular dementia mice through activating EPOR and its downstream JAK/STAT signaling pathway. DEPO is a potential alternative agent for treatment of vascular dementia or chronic cerebral ischemia.

Evolucollateral dynamics in stroke: Evolutionary pathophysiology, remodelling and emerging therapeutic strategies

Leptomeningeal collaterals (LMCs) are crucial in mitigating the impact of acute ischemic stroke (AIS) by providing alternate blood flow routes when primary arteries are obstructed. This article explores the evolutionary pathophysiology of LMCs, highlighting their critical function in stroke and the genetic and molecular mechanisms governing their development and remodelling. We address the translational challenges of applying animal model findings to human clinical scenarios, emphasizing the need for further research to validate emerging therapies-such as pharmacological agents, gene therapy and mechanical interventions-in clinical settings, aimed at enhancing collateral perfusion. Computational modelling emerges as a promising method for integrating experimental data, which requires precise parameterization and empirical validation. We introduce the 'Evolucollateral Dynamics' hypothesis, proposing a novel framework that incorporates evolutionary biology principles into therapeutic strategies, offering new perspectives on enhancing collateral circulation. This hypothesis emphasizes the role of genetic predispositions and environmental influences on collateral circulation, which may impact therapeutic strategies and optimize treatment outcomes. Future research must incorporate human clinical data to create robust treatment protocols, thereby maximizing the therapeutic potential of LMCs and improving outcomes for stroke patients.

Erythropoietin-derived peptide ARA290 mediates brain tissue protection through the β-common receptor in mice with cerebral ischemic stroke

AIM

To explore the neuroprotective effects of ARA290 and the role of β-common receptor (βCR) in a mouse model of middle cerebral artery occlusion (MCAO).

METHODS

This study included male C57BL/6J mice that underwent MCAO and reperfusion. The neuroprotective effect of ARA290 on MCAO-induced brain injury was investigated using neurological function tests (Longa and modified neurological severity score). Cerebral infarction was examined by 2, 3, 5-triphenyl tetrazolium chloride staining, neuronal apoptosis was assessed by immunofluorescence staining, blood parameters were measured using a flow cytometry-based automated hematology analyzer, liquid chromatography with tandem mass spectrometry was used to identify the serum metabolomics signature, inflammatory cytokines and liver index were detected by commercially available kits, and the protein levels of the erythropoietin (EPO) receptor and βCR were measured by western blot.

RESULTS

ARA290 exerted a qualitatively similar neuroprotective effect after MCAO as EPO. ARA290 significantly reduced neuronal apoptosis and the level of inflammatory cytokines in the brain tissue. However, ARA290's neuroprotective effect was significantly suppressed following the injection of siRNA against βCR.

CONCLUSION

ARA290 provided a neuroprotective effect via βCR in cerebral ischemic mice without causing erythropoiesis. This study provides novel insights into the role of ARA290 in ischemic stroke intervention.

Serum erythropoietin in acute ischemic stroke: preliminary findings

Ischemic stroke is the most common stroke, caused by occlusion of cerebral vessels and leading causes of disability. Erythropoietin (EPO) has non-hematopoietic effects as a neuroprotectant after ischemic event. This study aimed to learn the serum level of EPO in acute ischemic stroke. This cross-sectional study of ischemic stroke patients with onset < 24 h and consecutive sampling was used to collect the data from medical records review, physical examinations, head CT, 24-h EPO, 24-h and seventh-day NIHSS. A total of 47 patients consisting of 59.6% women, with a median age of 53 years old (21-70). The median 24 h EPO level was 808.6 pg/mL (134.2-2988.9). The relationship between 24 h-EPO and 24-h NIHSS were not significant (r = 0.101; p = 0.250), nor to 7th day NIHSS (r =  - 0.0174; p = 0.121) and to delta NIHSS (r = 0.186; p = 0.106). The relationship of blood collection time (hour) and EPO was significant (r =  - 0.260; p = 0.039). There was a statistically significant difference between serum EPO levels in ischemic stroke patients with lacunar stroke compared to non-lacunar stroke (288.5 vs. 855.4 ng/mL; p = 0.021). There was a relationship between the time of collection of blood and the level of EPO and also there was difference EPO level in lacunar stroke subtype compared with non-lacunar. The relationship between EPO and NIHSS lost significance after analysis. There is a need for a future study comparing each stroke risk factor and the same blood collection time.

Immune-Neurovascular Interactions in Experimental Perinatal and Childhood Arterial Ischemic Stroke

Emerging clinical and preclinical data have demonstrated that the pathophysiology of arterial ischemic stroke in the adult, neonates, and children share similar mechanisms that regulate brain damage but also have distinct molecular signatures and involved cellular pathways due to the maturational stage of the central nervous system and the immune system at the time of the insult. In this review, we discuss similarities and differences identified thus far in rodent models of 2 different diseases-neonatal (perinatal) and childhood arterial ischemic stroke. In particular, we review acquired knowledge of the role of resident and peripheral immune populations in modulating outcomes in models of perinatal and childhood arterial ischemic stroke and the most recent and relevant findings in relation to the immune-neurovascular crosstalk, and how the influence of inflammatory mediators is dependent on specific brain maturation stages. Finally, we discuss the current state of treatments geared toward age-appropriate therapies that signal via the immune-neurovascular interaction and consider sex differences to achieve successful translation.

One to one comparison of cell-free synthesized erythropoietin conjugates modified with linear polyglycerol and polyethylene glycol

With more than 20 Food and Drug Administration (FDA)-approved poly (ethylene glycol) (PEG) modified drugs on the market, PEG is the gold standard polymer in bioconjugation. The coupling improves stability, efficiency and can prolong blood circulation time of therapeutic proteins. Even though PEGylation is described as non-toxic and non-immunogenic, reports accumulate with data showing allergic reactions to PEG. Since PEG is not only applied in therapeutics, but can also be found in foods and cosmetics, anti-PEG-antibodies can occur even without a medical treatment. Hypersensitivity to PEG thereby can lead to a reduced drug efficiency, fast blood clearance and in rare cases anaphylactic reactions. Therefore, finding alternatives for PEG is crucial. In this study, we present linear polyglycerol (LPG) for bioconjugation as an alternative polymer to PEG. We report the conjugation of LPG and PEG by click-chemistry to the glycoprotein erythropoietin (EPO), synthesized in a eukaryotic cell-free protein synthesis system. Furthermore, the influence of the polymers on EPOs stability and activity on a growth hormone dependent cell-line was evaluated. The similar characteristics of both bioconjugates show that LPGylation can be a promising alternative to PEGylation.

Asialo-rhuEPO as a Potential Neuroprotectant for Ischemic Stroke Treatment

Neuroprotective drugs to protect the brain against cerebral ischemia and reperfusion (I/R) injury are urgently needed. Mammalian cell-produced recombinant human erythropoietin (rhuEPOM) has been demonstrated to have excellent neuroprotective functions in preclinical studies, but its neuroprotective properties could not be consistently translated in clinical trials. The clinical failure of rhuEPOM was thought to be mainly due to its erythropoietic activity-associated side effects. To exploit its tissue-protective property, various EPO derivatives with tissue-protective function only have been developed. Among them, asialo-rhuEPO, lacking terminal sialic acid residues, was shown to be neuroprotective but non-erythropoietic. Asialo-rhuEPO can be prepared by enzymatic removal of sialic acid residues from rhuEPOM (asialo-rhuEPOE) or by expressing human EPO gene in glycoengineered transgenic plants (asialo-rhuEPOP). Both types of asialo-rhuEPO, like rhuEPOM, displayed excellent neuroprotective effects by regulating multiple cellular pathways in cerebral I/R animal models. In this review, we describe the structure and properties of EPO and asialo-rhuEPO, summarize the progress on neuroprotective studies of asialo-rhuEPO and rhuEPOM, discuss potential reasons for the clinical failure of rhuEPOM with acute ischemic stroke patients, and advocate future studies needed to develop asialo-rhuEPO as a multimodal neuroprotectant for ischemic stroke treatment.

Correlation between Serum Erythropoietin and Cerebral Collateral Flow in Acute Ischemic Stroke Patient

BACKGROUND

Erythropoietin (EPO), which is associated with anemia, exerts neuroprotective effects in ischemic stroke. In cases of stenosis or narrowing of the main cerebral blood vessel, the prognosis is favorable if collateral blood circulation is well developed in acute stroke. Several studies have investigated the relationship between EPO administration and stroke outcomes. The present study investigated the correlation between serum EPO level and cerebral collateral circulation, which could result in favorable clinical outcomes.

METHODS

The study subjects were patients diagnosed with acute ischemic stroke who underwent initial brain magnetic resonance imaging between January 2020 and March 2022. Following brain computed tomography perfusion for collateral flow, serum EPO levels were measured. Collaterals were assessed according to the Mass system and divided into good collateral (GC) or poor collateral (PC) groups. Serum EPO levels were determined using a chemiluminescence immunoassay method. A correlation coefficient analysis was conducted to determine the correlation between serum EPO levels and GC. A receiver operating characteristic curve analysis determined the cutoff value of EPO for GC.

RESULTS

Serum EPO levels were significantly higher in the GC than that in the PC group (P<0.05). The cut-off level of serum EPO for a good outcome was 9.1 mIU/mL.

CONCLUSION

A high serum EPO (>9.1 mIU/mL) could be a marker of GC in patients with acute ischemic stroke that predicts good clinical outcomes.

The therapeutic role of Jingchuan tablet on ischaemic cerebral stroke via the HIF-1α/EPO/VEGFA signalling pathway

CONTEXT

Jingchuan tablet (JCT) is a Chinese medicine prescription for treating ischaemic cerebral stroke (ICS). However, its relevant mechanisms remain unclear.

OBJECTIVE

To unravel the intrinsic mechanisms of JCT anti-ICS.

MATERIALS AND METHODS

'Hongjingtian', 'chuanxiong', 'yanhusuo', 'bingpian', 'cerebral infarction', 'cerebral ischemia' or 'stroke' were used as keywords, and then components, targets and underlying mechanisms of JCT anti-ICS were analysed in TCMSP, TTD, DrugBank, STRING and Metascape databases up to June 2020. Male Sprague-Dawley rats under permanent middle cerebral artery occlusion (pMCAO) model, randomly assigned as: model, sham, nimodipine (0.012 g/kg/d) and JCT (0.78, 1.56 and 3.12 g/kg/d) groups, received oral gavage administration for a week. Therapeutic effects were evaluated by detecting the proportion of cerebral infarction, neuronal apoptosis and neurological deficits. Bioactive components were detected by HPLC-MS. Molecular biology and computational docking were used to verify the underlying mechanisms.

RESULTS

Eighty-one components, 166 targets and HIF-1α/EPO/VEGFA pathway contributed to the anti-ICS effect of JCT. JCT treatment effectively reduced the proportion of cerebral infarction (33.13%), apoptosis rate (14.80%) and neurobehavioural score (2.00). JCT increased the protein levels of HIF-1α (0.84), EPO (0.64) and VEGFA (0.69), respectively (p < 0.05). Gallic acid, salidroside, chlorogenic acid, ethyl gallate, ferulic acid and tetrahydropalmatine detected by HPLC-MS showed good interaction and binding with HIF-1α/EPO/VEGFA.

CONCLUSIONS

Our study demonstrated the mechanisms of JCT anti-ICS associated with the activation of the HIF-1α/EPO/VEGFA pathway, which provided a pharmacological basis for expanding the clinical application and some scientific ideas for further research into the material basis JCT anti-ICS.

Therapeutic Use and Chronic Abuse of CNS Stimulants and Anabolic Drugs

The available evidence suggests that affective disorders, such as depression and anxiety, increase risk for accelerated cognitive decline and late-life dementia in aging individuals. Behavioral neuropsychology studies also showed that cognitive decline is a central feature of aging impacting the quality of life. Motor deficits are common after traumatic brain injuries and stroke, affect subjective well-being, and are linked with reduced quality of life. Currently, restorative therapies that target the brain directly to restore cognitive and motor tasks in aging and disease are available. However, the very same drugs used for therapeutic purposes are employed by athletes as stimulants either to increase performance for fame and financial rewards or as recreational drugs. Unfortunately, most of these drugs have severe side effects and pose a serious threat to the health of athletes. The use of performance-enhancing drugs by children and teenagers has increased tremendously due to the decrease in the age of players in competitive sports and the availability of various stimulants in many forms and shapes. Thus, doping may cause serious health-threatening conditions including, infertility, subdural hematomas, liver and kidney dysfunction, peripheral edema, cardiac hypertrophy, myocardial ischemia, thrombosis, and cardiovascular disease. In this review, we focus on the impact of doping on psychopathological disorders, cognition, and depression. Occasionally, we also refer to chronic use of therapeutic drugs to increase physical performance and highlight the underlying mechanisms. We conclude that raising awareness on the health risks of doping in sport for all shall promote an increased awareness for healthy lifestyles across all generations.

Evolution of ischemic stroke drug clinical trials in mainland China from 2005 to 2021

Background

To assess the temporal changes in the characteristics of ischemic stroke drug clinical trials conducted in mainland China in 2005–2021.

Methods

A statistical analysis of registered clinical trials on ischemic stroke was performed using the platform of the Center for Drug Evaluation of China National Medical Products Administration, the Chinese Clinical Trial Registry, and ClinicalTrials.gov websites.

Results

From January 1, 2005 to August 1, 2021, a total of 384 registered drug clinical trials on ischemic stroke were identified in mainland China. Over time, the number of trials gradually increased each year, with a significant growth in 2014, from 16 in 2013 to 42 in 2014. Phase IV trials (31.8%) accounted for the majority, followed by phase II (16.4%), phase I (10.9%), and phase III (8.6%). In terms of sponsorship, the proportion of investigator‐initiated trials (IITs) (60.7%) was higher than industry‐sponsored trials (ISTs) (39.3%). Additionally, trials involving traditional Chinese medicines (TCMs) (36.2%) accounted for the largest proportion, followed by trials involving antithrombotic therapy (19.5%) and cerebral protection agents (16.7%). Furthermore, over the past 17 years, the number of leading drug clinical trial units for ischemic stroke in mainland China has continuously increased. The leading principal units from Beijing, Shanghai, Guangdong, Jiangsu, and Liaoning accounted for the majority of the trials (67.4%).

Conclusion

In the past 17 years, great progress has been made in the research and development (R&D) of drugs and clinical trials for ischemic stroke in mainland China. The most extensive progress was observed in TCMs, antithrombotic therapy, and cerebral protection agents. More clinical trials are needed to confirm whether the newly developed drugs can improve the clinical efficacy of ischemic stroke. Simultaneously, more pharmaceutical R&D efforts of innovative drugs are warranted.