Deferoxamine therapy reduces brain hemin accumulation after intracerebral hemorrhage in piglets

Hemin promotes platelet activation and plasma membrane disintegration regulated by the subtilisin-like proprotein convertase furin

Platelet activation plays a critical role in thrombosis and hemostasis. Several pathophysiological situations lead to hemolysis, resulting in the liberation of free ferric iron-containing hemin. Hemin has been shown to activate platelets and induce thrombo-inflammation. Classical antiplatelet therapy failed to prevent hemin-induced platelet activation. Thus, the aim of the present study was to characterize the mechanism of hemin-induced platelet death (ferroptosis). We evaluated the in vitro effect of hemin on platelet activation, signaling, oxylipins, and plasma membrane destruction using light transmission aggregometry, ex vivo thrombus formation, multiparametric flow cytometry, micro-UHPLC mass spectrometry for oxylipin profiling, and scanning ion conductance microscopy (SICM). We found that hemin induces platelet cell death indicated by increased ROS levels, phosphatidyl serine (PS) exposure, and loss of mitochondrial membrane potential (ΔΨm). Further, hemin causes lipid peroxidation and generation of distinct oxylipins, which strongly affects plasma membrane integrity leading to generation of platelet-derived microvesicles. Interestingly, hemin-dependent platelet death (ferroptosis) is specifically regulated by the subtilisin-like proprotein convertase furin. In summary, platelet undergo a non-apoptotic cell death mediated by furin. Inhibition of furin may offer a therapeutic strategy to control hemin-induced thrombosis and thrombo-inflammation at a site of hemolysis.

Comparing white and gray matter responses to lobar intracerebral hemorrhage in piglets and the effects of deferoxamine

BACKGROUND

Intracerebral hemorrhage (ICH) often impacts patient white matter. However, preclinically, the effects of ICH are mostly studied in rodents with sparse white matter. This study used a lobar porcine ICH model to examine differences in the effects of ICH on white and gray matter as well as the role of the iron chelator deferoxamine (DFX), on attenuation of such injury.

METHODS

This two-part study was performed in piglets. Firstly, piglets had a needle (Sham) or 2.5 ml blood injection (ICH) and were euthanized at day 3. Secondly, animals were treated with vehicle or DFX after ICH and were euthanized at day 3. White and gray matter edema, the number of oligodendrocytes (mature and immature) and neurons, and the number of Perls' (iron), ferritin and heme oxygenase (HO)-1 positive cells were examined.

RESULTS

At day 3, ICH induced greater edema formation in white than gray matter. This marked white matter edema was associated with a loss of mature, but not immature, oligodendrocytes. ICH also induced neuronal death in gray matter. There were also marked increases in Perls', ferritin and HO-1 positive cells after ICH in both white and gray matter, but significantly more in the former. DFX attenuated ICH-induced brain edema in white but not gray matter and this was associated with increased survival of mature oligodendrocytes. DFX also increased survival of neurons in the gray matter and it reduced the number of Perls', ferritin and HO-1 positive cells in both tissue types.

CONCLUSIONS

While there were commonalities in perihematomal changes between white and gray matter after ICH, there was greater edema in white matter which may be linked to the susceptibility of mature oligodendrocytes to ICH injury. Similarly, while DFX reduced perihematomal iron overload in both white and gray matter, it only significantly reduced edema in white matter where it increased the number of mature oligodendrocytes.

The role of metal ions in stroke: Current evidence and future perspectives

Metal ions play a pivotal role in maintaining optimal brain function within the human body. Nevertheless, the accumulation of these ions can result in irregularities that lead to brain damage and dysfunction. Disruptions of metal ion homeostasis can result in various pathologies, including inflammation, redox dysregulation, and blood-brain barrier disruption. While research on metal ions has chiefly focused on neurodegenerative diseases, little attention has been given to their involvement in the onset and progression of stroke. Recent studies have identified cuproptosis and confirmed ferroptosis as significant factors in stroke pathology, underscoring the importance of metal ions in stroke pathology, including abnormal ion transport, neurotoxicity, blood-brain barrier damage, and cell death. Additionally, it provides an overview of contemporary metal ion chelators and detection techniques, which may offer novel approaches to stroke treatment.

Sanguiin inhibits cerebral hemorrhage in rats by protecting the blood-brain barrier

Introduction

The aim of the study was to observe the effect of Sanguiin on cerebral edema and behavior in a rat cerebral hemorrhage model.

Methods

A rat collagenase-induced cerebral hemorrhage model was established to detect the effects of drugs on brain edema.

Results

Through magnetic resonance imaging (MRI) analysis and brain weight content (BWC) determination, it was found that Sanguiin could significantly reduce the brain swelling index and BWC of the affected hemisphere after cerebral hemorrhage.

Conclusions

Sanguiin can significantly improve the neurological deficits in rats with cerebral hemorrhage, and down-regulate the expression of MMP-9 after cerebral hemorrhage, suggesting that Sanguiin has a certain protective effect on the blood-brain barrier after cerebral hemorrhage.

Macrophage Ferroptosis Promotes MMP2/9 Overexpression Induced by Hemin in Hemorrhagic Plaque

BACKGROUND

 Intra-plaque hemorrhage (IPH) leads to rapid plaque progression and instability through upregulation of matrix metalloproteinases (MMPs) and collagen degradation. Hemoglobin-derived hemin during IPH promotes plaque instability. We investigated whether hemin affects MMP overexpression in macrophages and explored the underlying mechanisms.

MATERIAL AND METHODS

 In vivo, hemorrhagic plaque models were established in rabbits and ApoE-/- mice. Ferrostatin-1 was used to inhibit ferroptosis. Plaque size, collagen, and MMP2/9 levels were evaluated using immunohistochemistry, H&E, Sirius Red, and Masson staining. In vitro, mouse peritoneal macrophages were extracted. Western blot and ELISA were used to measure MMP2/9 levels. Bioinformatics analysis investigated the association between MMPs and ferroptosis pathway genes. Macrophage ferroptosis was assessed by evaluating cell viability, lipid reactive oxygen species, mitochondrial ultrastructure, iron content, and COX2 levels after pretreatment with cell death inhibitors. Hemin's impact on ferroptosis and MMP expression was studied using Ferrostatin-1 and SB202190.

RESULTS

 In the rabbit hemorrhagic plaques, hemin deposition and overexpression of MMP2/9 were observed, particularly in macrophage-enriched regions. In vitro, hemin induced ferroptosis and MMP2/9 expression in macrophages. Ferrostatin-1 and SB202190 inhibited hemin-induced MMP2/9 overexpression. Ferrostatin-1 inhibited p38 phosphorylation in macrophages. Ferostatin-1 inhibits macrophage ferroptosis, reduces MMP2/9 levels in plaques, and stabilizes the hemorrhagic plaques.

CONCLUSION

 Our results suggested that hemin-induced macrophage ferroptosis promotes p38 pathway activation and MMP2/9 overexpression, which may play a crucial role in increasing hemorrhagic plaque vulnerability. These findings provide insights into the pathogenesis of hemorrhagic plaques and suggest that targeting macrophage ferroptosis may be a promising strategy for stabilizing vulnerable plaque.

Rational synthesis of FeNiCo-LDH nanozyme for colorimetric detection of deferoxamine mesylate

The accurate surveillance and sensitive detection of deferoxamine mesylate (DFO) is of great significance to ensure the safety of thalassemia major patients. Herein, we report a new nanozyme-based colorimetric sensor platform for DFO detection. First, a metal-organic framework (ZIF-67) was used as a precursor for the synthesis of FeNiCo-LDH (Layered Double Hydroxide, LDH) via an ion exchange reaction stirring at room temperature. The results of electron microscopy and nitrogen adsorption-desorption showed that FeNiCo-LDH exhibited a 3D hollow and mesopores structure, which supplied more exposed active sites and faster transfer of mass. The as-prepared FeNiCo-LDH showed superior peroxidase-like activity with a low Km and high υmax. It can catalyze the decomposition of H2O2 to generate reactive oxygen species (ROS) and further react with 3,3',5,5'-tetramethylbenzidine (TMB) to form blue oxidized TMB (oxTMB), which has a characteristic absorption at 652 nm. Once DFO was introduced, it can complex with FeNiCo-LDH and inhibit the peroxidase-like activity of FeNiCo-LDH, making the color of oxTMB lighter. The quantitative range of DFO was 0.8-28 μM with a detection limit of 0.71 μM. This established method was applied to the detection of DFO content in urine samples of thalassemia patients, and the spiked recoveries were falling between 97.7% and 109.6%, with a relative standard deviation was less than 5%, providing a promising tool for the clinical medication of thalassemia patients.

Role of mass effect on neuronal iron deposition after intracerebral hemorrhage

Mass effect after intracerebral hemorrhage (ICH) not only mechanically induces the brain damage, but also influences the progress of secondary brain damage. However, the influence of mass effect on the iron overload after ICH is still unclear. Here, a fixed volume of ferrous chloride solution and different volumes of poly(N-isopropylacrylamide) (PNIPAM) hydrogel were co-injected into the right basal ganglia of rats to establish the ICH model with certain degree of iron deposition but different degrees of mass effect. We found that mass effect significantly increased the iron deposition on neuronal cells at 6 h after ICH in a volume-dependent manner. Furthermore, the upregulation of Piezo-2, divalent metal transporter 1 (DMT1), transferrin receptor (TfR), and ferroptosis expressions were noted as the increase of mass effect. In addition, the pERK1/2 inhibitor PD98059 treated ICH rats reversed the upregulation of iron uptake protein and ferroptosis. Our findings revealed the relationship between mass effect and the iron uptake and ferroptosis, which are benefit to understand the brain damage process after ICH.

Research progress of endogenous hematoma absorption after intracerebral hemorrhage

Non-traumatic intraparenchymal brain hemorrhage is referred to as intracerebral hemorrhage (ICH). Although ICH is associated with a high rate of disability and case fatality, active intervention can significantly lower the rate of severe disability. Studies have shown that the speed of hematoma clearance after ICH determines the patient's prognosis. Following ICH, depending on the hematoma volume and mass effect, either surgical- or medication-only conservative treatment is chosen. The goal of promoting endogenous hematoma absorption is more relevant because surgery is only appropriate for a small percentage of patients, and open surgery can cause additional trauma to patients. The primary method of removing hematoma after ICH in the future will involve understanding how to produce and manage macrophage/microglial endogenous phagocytic hematomas. Therefore, it is necessary to elucidate the regulatory mechanisms and key targets for clinical purposes.

The Critical Role of Erythrolysis and Microglia/Macrophages in Clot Resolution After Intracerebral Hemorrhage: A Review of the Mechanisms and Potential Therapeutic Targets

Intracerebral hemorrhage (ICH) is a common cerebrovascular disorder with high morbidity and mortality. Secondary brain injury after ICH, which is initiated by multiple hemolytic products during erythrolysis, has been identified as a critical factor accounting for the poor prognosis of ICH patients. Clot resolution and hematoma clearance occur immediately after ICH via erythrolysis and erythrophagocytosis. During this process, erythrolysis after ICH results in the release of hemoglobin and products of degradation along with rapid morphological changes in red blood cells (RBCs). Phagocytosis of deformed erythrocytes and products of degradation by microglia/macrophages accelerates hematoma clearance, which turns out to be neuroprotective. Thus, a better understanding of the mechanism of erythrolysis and the role of microglia/macrophages after ICH is urgently needed. In this review, the current research progresses on the underlying mechanism of erythrolysis and erythrophagocytosis, as well as several useful tools for the quantification of erythrolysis-induced brain injury, are summarized, providing potential intervention targets and possible treatment strategies for ICH patients.

Inhibition of CCR2 attenuates neuroinflammation and neuronal apoptosis after subarachnoid hemorrhage through the PI3K/Akt pathway

BACKGROUND

Neuroinflammation and neuronal apoptosis are closely associated with a poor prognosis in patients with subarachnoid hemorrhage (SAH). We investigated the role of C-C motif chemokine receptor 2 (CCR2) in SAH.

METHODS

Pre-processed RNA-seq transcriptome datasets GSE167110 and GSE79416 from the Gene Expression Omnibus (GEO) database were screened for genes differentially expressed between mice with SAH and control mice, using bioinformatics analysis. The endovascular perforation model was performed to establish SAH. RS504393 (a CCR2 antagonist) and LY294002 (PI3K inhibitor) were administered to explore the mechanism of neuroinflammation after SAH. SAH grading, neurological scoring, brain water content and blood-brain barrier (BBB) permeability determination, enzyme-linked immunosorbent assay (ELISA), western blotting, and immunofluorescence were performed. An in vitro model of SAH was induced in H22 cells by hemin treatment. The protective mechanism of CCR2 inhibition was studied by adding RS504393 and LY294002. Clinical cerebrospinal fluid (CST) samples were detected by ELISA.

RESULTS

Expression of CCR2 was upregulated in both datasets and was identified as a hub gene. CCR2 expression was significantly upregulated in the cytoplasm of neurons after SAH, both in vitro and in vivo. RS significantly reduced the brain water content and blood-brain barrier permeability, alleviated neuroinflammation, and reduced neuronal apoptosis after SAH. Additionally, the protective effects of CCR2 inhibition were abolished by LY treatment. Finally, the levels of CCR2, inflammatory factors, and apoptotic factors were elevated in the CSF of patients with SAH. CCR2 levels were associated with patient outcomes at the 6-month follow-up.

CONCLUSION

CCR2 expression was upregulated in both in vitro and in vivo SAH models. Additionally, inhibition of CCR2, at least partly through the PI3K/AKT pathway, alleviated neuroinflammation and neuronal apoptosis in vivo and in vitro. CCR2 levels in the CSF have a moderate diagnostic value for 6-month outcome prediction in patients with SAH.

Therapeutic strategies for intracerebral hemorrhage

Stroke is the second highest cause of death globally, with an increasing incidence in developing countries. Intracerebral hemorrhage (ICH) accounts for 10-15% of all strokes. ICH is associated with poor neurological outcomes and high mortality due to the combination of primary and secondary injury. Fortunately, experimental therapies are available that may improve functional outcomes in patients with ICH. These therapies targeting secondary brain injury have attracted substantial attention in their translational potential. Here, we summarize recent advances in therapeutic strategies and directions for ICH and discuss the barriers and issues that need to be overcome to improve ICH prognosis.

Neuroinflammation of microglia polarization in intracerebral hemorrhage and its potential targets for intervention

Microglia are the resident immune cells of the central nervous system (CNS) and play a key role in neurological diseases, including intracerebral hemorrhage (ICH). Microglia are activated to acquire either pro-inflammatory or anti-inflammatory phenotypes. After the onset of ICH, pro-inflammatory mediators produced by microglia at the early stages serve as a crucial character in neuroinflammation. Conversely, switching the microglial shift to an anti-inflammatory phenotype could alleviate inflammatory response and incite recovery. This review will elucidate the dynamic profiles of microglia phenotypes and their available shift following ICH. This study can facilitate an understanding of the self-regulatory functions of the immune system involving the shift of microglia phenotypes in ICH. Moreover, suggestions for future preclinical and clinical research and potential intervention strategies are discussed.

Efficacy of desferrioxamine mesylate in intracerebral hematoma: a systemic review and meta-analysis

Background

Previous meta-analysis had concluded that desferrioxamine mesylate (DFO) could effectively treat intracerebral hematoma (ICH) in animal models. We hope to confirm that DFO could treat ICH patients effectively through the systemic review and meta-analysis of clinical researches.

Method

Data extraction included hematoma volume (HV), reduction of National Institute of Health Stroke Scale (NIHSS) scores, and relative perihematomal edema (RPHE). The standard mean difference (SMD) and 95% confidence interval (95%CI) were calculated by fixed effects model. I-square (I²) statistic was used to test the heterogeneity. All p values were two-side with a significant level at 0.05.

Results

Five randomized controlled trials were included in the meta-analysis, which included 239 patients. At 7 days after onset, there was significant difference of RPHE development (− 1.87 (− 2.22, − 1.51) (I² = 0, p = 0.639)) and significant difference of HV absorption (− 0.71 (− 1.06, 0.36) (I² = 17.5%, p = 0.271)) between DFO and control groups. There was significant difference of reduction of NHISS scores (0.25 (0.05, 0.46) (I² = 0, p = 0.992)) between DFO and control groups at 30 days after onset.

Conclusion

DFO reduced HV and perihematomal edema in ICH patients at 7 days after onset and improve neurological function at 30 days after onset efficiently and safely. DFO might be a new route of improving treatment of ICH.

Iron Neurotoxicity and Protection by Deferoxamine in Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is a subtype of stroke that is characterized by high morbidity and mortality, for which clinical outcome remains poor. An extensive literature indicates that the release of ferrous iron from ruptured erythrocytes in the hematoma is a key pathogenic factor in ICH-induced brain injury. Deferoxamine is an FDA-approved iron chelator that has the capacity to penetrate the blood-brain barrier after systemic administration and binds to iron. Previous animal studies have shown that deferoxamine attenuates ICH-induced brain edema, neuronal death, and neurological deficits. This review summarizes recent progress of the mechanisms by which deferoxamine may alleviate ICH and discusses further studies on its clinical utility.

Novel targets, treatments, and advanced models for intracerebral haemorrhage

Intracerebral haemorrhage (ICH) is the second most common type of stroke and a major cause of mortality and disability worldwide. Despite advances in surgical interventions and acute ICH management, there is currently no effective therapy to improve functional outcomes in patients. Recently, there has been tremendous progress uncovering new pathophysiological mechanisms underlying ICH that may pave the way for the development of therapeutic interventions. Here, we highlight emerging targets, but also existing gaps in preclinical animal modelling that prevent their exploitation. We particularly focus on (1) ICH aetiology, (2) the haematoma, (3) inflammation, and (4) post-ICH pathology. It is important to recognize that beyond neurons and the brain, other cell types and organs are crucially involved in ICH pathophysiology and successful interventions likely will need to address the entire organism. This review will spur the development of successful therapeutic interventions for ICH and advanced animal models that better reflect its aetiology and pathophysiology.

Iron toxicity in intracerebral hemorrhage: Physiopathological and therapeutic implications

Intracerebral hemorrhage (ICH)-induced brain injury is a continuous pathological process that involves the deterioration of neurological functions, such as sensory, cognitive or motor functions. Cytotoxic byproducts of red blood cell lysis, especially free iron, appear to be a significant pathophysiologic mechanism leading to ICH-induced injury. Free iron has a crucial role in secondary brain injury after ICH. Chelating iron may attenuate iron-induced neurotoxicity and may be developed as a therapeutic candidate for ICH treatment. In this review, we focused on the potential role of iron toxicity in ICH-induced injury and iron chelation therapy in the management of ICH. It will hopefully advance our understanding of the pathogenesis of ICH and lead to new approaches for treatment.

Microglia Phenotype and Intracerebral Hemorrhage: A Balance of Yin and Yang

Intracerebral hemorrhage (ICH) features extremely high rates of morbidity and mortality, with no specific and effective therapy. And local inflammation caused by the over-activated immune cells seriously damages the recovery of neurological function after ICH. Fortunately, immune intervention to microglia has provided new methods and ideas for ICH treatment. Microglia, as the resident immune cells in the brain, play vital roles in both tissue damage and repair processes after ICH. The perihematomal activated microglia not only arouse acute inflammatory responses, oxidative stress, excitotoxicity, and cytotoxicity to cause neuron death, but also show another phenotype that inhibit inflammation, clear hematoma and promote tissue regeneration. The proportion of microglia phenotypes determines the progression of brain tissue damage or repair after ICH. Therefore, microglia may be a promising and imperative therapeutic target for ICH. In this review, we discuss the dual functions of microglia in the brain after an ICH from immunological perspective, elaborate on the activation mechanism of perihematomal microglia, and summarize related therapeutic drugs researches.

Scalp Acupuncture Protects Against Neuronal Ferroptosis by Activating The p62-Keap1-Nrf2 Pathway in Rat Models of Intracranial Haemorrhage

Intracerebral haemorrhage (ICH) can be a catastrophic event; even if the initial stages of the pathology were well-managed, a number of patients experience varied residual neurological deficits following the insult. Ferroptosis is a recently identified type of cell demise which is tightly linked to the neurological impairment associated with ICH. In the current work, the prophylactic impact of scalp acupuncture (SA) therapy on autologous blood injection murine models of ICH was investigated in order to establish whether SA could mitigate the secondary damage arising following ICH by moderating ferroptosis. The pathophysiological mechanisms associated with this process were also explored. Ludmila Belayev tests were utilised for the characterisation of neurological damage. Haematoxylin–eosin staining was employed in order to determine the cerebral impact of the induced ICH. Malondialdehyde (MDA) and iron titres in peri-haemorrhagic cerebral tissues were appraised using purchased assay kits. Transmission electron microscopy delineated mitochondrial appearances within nerve cell bodies from the area of haemorrhage. Western blotting techniques were utilised to assay the degree of protein expression of NeuN, sequestosome 1 (p62), nuclear factor erythroid 2-related factor 2 (Nrf2), Kelch-like ECH-associated protein 1 (Keap1), glutathione peroxidase 4 (GPX4) and ferritin heavy chain 1 (FTH1). The frequencies of Nrf2, GPX4 and FTH1 positive cells, respectively, were documented with immunohistochemical staining. The results demonstrated that therapy with SA after ICH mitigated MDA and iron sequestration, diminished the appearance of contracted mitochondria with increased outer mitochondrial membrane diameter within the nerve cell bodies, and suppressed neuronal ferroptosis. The pathways responsible for these effects may encompass amplified p62, Nrf2, GPX4 and FTH1 expression, together with decreased Keap1 expression. Application of SA reduced identified neurobehavioural abnormalities after ICH; no disparities were observed between the consequences of SA therapy and deferoxamine delivery. It can be surmised that intervention with SA enhanced recovery after ICH by triggering the antioxidant pathway, p62/Keap1/Nrf2, and causing FTH1 and GPX4 upregulation, factors that participate in diminishing excess iron and thus in mitigating lipid peroxidation insults arising from ferroptosis following ICH.

Iron chelation suppresses secondary bleeding after intracerebral hemorrhage in angiotensin II-infused mice

AIMS

Secondary bleeding and further hematoma expansion (HE) aggravate brain injury after intracerebral hemorrhage (ICH). The majority of HE results from hypertensive ICH. Previous study reported higher iron content in the brains of hypertensive patients. Iron overload exacerbates the risk of hemorrhagic transformation in thromboembolic stroke mice. Whether iron overload during the process of hypertension participates in secondary bleeding of hypertensive ICH remains unclear.

METHODS

Hypertension was induced by continuous infusion of angiotensin II (Ang II) with an osmotic pump into C57BL/6 mice. ICH was simulated by intrastriatal injection of the liquid polymer Onyx-18. Iron chelation and iron overload was achieved by deferoxamine mesylate or iron dextran injection. Secondary bleeding was quantified by measuring the hemoglobin content in the ipsilateral brain hemisphere.

RESULTS

Ang II-induced hypertensive mice showed increased iron accumulation in the brain and expanded secondary hemorrhage after ICH modeling. Moreover, iron chelation suppressed while iron overload aggravated secondary bleeding. Mechanistically, iron exacerbated the loss of contractile cerebral vascular smooth muscle cells (VSMCs), aggravated blood-brain barrier (BBB) leakage in Ang II-induced hypertensive mice, and increased glial and MMP9 accumulation after ICH.

CONCLUSION

Iron overload plays a key role in secondary bleeding after ICH in Ang II-induced hypertensive mice. Iron chelation during the process of Ang II-induced hypertension suppresses secondary bleeding after ICH.

Neuroprotective Therapies for Spontaneous Intracerebral Hemorrhage

Patients who survive the initial ictus of spontaneous intracerebral hemorrhage (ICH) remain vulnerable to subsequent injury of the perilesional parenchyma by molecular and cellular responses to the hematoma. Secondary brain injury after ICH, which contributes to long-term functional impairment and mortality, has emerged as an attractive therapeutic target. This review summarizes preclinical and clinical evidence for neuroprotective therapies targeting secondary injury pathways following ICH. A focus on therapies with pleiotropic antiinflammatory effects that target thrombin-mediated chemotaxis and inflammatory cell migration has led to studies investigating statins, anticholinergics, sphingosine-1-phosphate receptor modulators, peroxisome proliferator activated receptor gamma agonists, and magnesium. Attempts to modulate ICH-induced blood-brain barrier breakdown and perihematomal edema formation has prompted studies of nonsteroidal antiinflammatory agents, matrix metalloproteinase inhibitors, and complement inhibitors. Iron chelators, such as deferoxamine and albumin, have been used to reduce the free radical injury that ensues from erythrocyte lysis. Stem cell transplantation has been assessed for its potential to enhance subacute neurogenesis and functional recovery. Despite promising preclinical results of numerous agents, their outcomes have not yet translated into positive clinical trials in patients with ICH. Further studies are necessary to improve our understanding of the molecular events that promote damage and inflammation of the perihematomal parenchyma after ICH. Elucidating the temporal and pathophysiologic features of this secondary brain injury could enhance the clinical efficacy of neuroprotective therapies for ICH.

Anti-CD47 antibody administration via cisterna magna in proper dosage can reduce perihematomal cell death following intracerebral hemorrhage in rats

OBJECTIVE

The secondary injury caused by RBC autolysis after intracerebral hemorrhage (ICH) can be reduced by increasing the efficiency of microglia (MG)/macrophages (Mø) phagocytizing red blood cells (RBCs). CD47 is an important regulator of MG/Mø phagocytosis. This study aims to clarify whether anti-CD47 antibody administrated into the cisterna magna after ICH can transfer to the hematoma site, promote MG/Mø gathering to phagocytize RBCs and ultimately reduce cell death.

METHODS

Forty male Wistar rats were divided into sham, ICH, low-dosage (group A, 0.3 μg), medium-dosage (group B, 0.9 μg) and high-dosage (group C, 1.8 μg) anti-CD47 antibody groups. For the rats in group A, B and C, anti-CD47 antibody solution was administrated into the cisterna magna at 10 min after ICH. Brain tissue was harvested 3 days after the operation. Western blotting was performed to detect the expression of Caspase-3 and Bcl-2. Immunofluorescence was performed to detect the CD68 expression. TUNEL was performed to detect the cell death.

RESULTS

The hematoma of the ICH rats was located in the basal ganglia, with a good homogeneity of hematoma volume. Low-dosage anti-CD47 antibody in group A had no effects on the perihematomal CD68 (P = 0.338), Caspase-3 (P = 0.769), Bcl-2 (P = 0.176) expression and cell death (P = 0.698), compared with the ICH group. CD68 and Bcl-2 expression increased and Caspase-3 expression decreased significantly in group B (P < 0.001 for all) and group C (P < 0.001 for all). The increase of CD68 expression in group C was greater than that in group B (P < 0.01) by a large margin, while there was no difference for Bcl-2 (P = 0.908) and Caspase-3 (P = 0.913) expression between the 2 groups. Compared with the ICH group, medium-dosage of anti-CD47 antibody in group B significantly reduced the number of TUNEL-positive cells (P < 0.005), but not for group C (P = 0.311).

CONCLUSION

The results suggested that anti-CD47 antibody administration into the cisterna magna in proper dosage (0.9 μg) can effectively reach the hematoma, induce more MG/Møs to gather around the hematoma, and reduce cell death in perihematomal brain tissue. The results of this study has provided a basic theory for improving the efficiency of MG/Mø phagocytizing RBCs and hematoma clearance after ICH by administrating anti-CD47 antibody via the cisterna magna.

Deferoxamine B: A Natural, Excellent and Versatile Metal Chelator

Deferoxamine B is an outstanding molecule which has been widely studied in the past decade for its ability to bind iron and many other metal ions. The versatility of this metal chelator makes it suitable for a number of medicinal and analytical applications, from the well-known iron chelation therapy to the most recent use in sensor devices. The three bidentate hydroxamic functional groups of deferoxamine B are the centerpiece of its metal binding ability, which allows the formation of stable complexes with many transition, lanthanoid and actinoid metal ions. In addition to the ferric ion, in fact, more than 20 different metal complexes of deferoxamine b have been characterized in terms of their chemical speciation in solution. In addition, the availability of a terminal amino group, most often not involved in complexation, opens the way to deferoxamine B modification and functionalization. This review aims to collect and summarize the available data concerning the complex-formation equilibria in solutions of deferoxamine B with different metal ions. A general overview of the progress of its applications over the past decade is also discussed, including the treatment of iron overload-associated diseases, its clinical use against cancer and neurodegenerative disorders and its role as a diagnostic tool.

Role of mass effect and trehalose on early erythrolysis after experimental intracerebral hemorrhage

The mechanisms of brain injury after intracerebral hemorrhage (ICH) involve mass effect-induced primary injury and secondary injury caused by a pathologic response to the hematoma. Considerable attentions have recently been paid to the mechanisms and therapeutic strategy for secondary brain injury due to no overall benefit from early surgery compared with initial conservative treatment. However, it is unclear whether there is a causal relationship between mass effect and secondary brain injury. Here, the role of mass effect on early erythrolysis after experimental ICH was investigated based on the poly(N-isopropylacrylamide) (PNIPAM) ICH model. Autologous blood and PNIPAM hydrogel were co-injected into the right basal ganglia of rats to induce different degrees of mass effect, but with a constant hematoma. The influences of different mass effect and time courses on erythrolysis and brain damages after ICH were investigated. Furthermore, the protective effect of trehalose against erythrolysis after ICH was evaluated. The results showed that mass effect caused erythrocyte morphological change at 24 hr after ICH. The released hemoglobin was quantitatively evaluated by a polynomial concerning with the mass effect, the volume of hematoma, and the time of ICH. An obvious increase in heme oxygenase-1 (HO-1) and ionized calcium binding adaptor molecule-1 (Iba-1) expression, iron deposition, cell death, and neurological deficits was observed with increasing mass effect. Moreover, trehalose alleviated brain injury by inhibiting erythrolysis after ICH. These data demonstrated that mass effect accelerated the erythrolysis and brain damages after ICH, which could be relieved through trehalose therapy.

Neurovascular Units and Neural-Glia Networks in Intracerebral Hemorrhage: from Mechanisms to Translation

Intracerebral hemorrhage (ICH), the most lethal type of stroke, often leads to poor outcomes in the clinic. Due to the complex mechanisms and cell-cell crosstalk during ICH, the neurovascular unit (NVU) was proposed to serve as a promising therapeutic target for ICH research. This review aims to summarize the development of pathophysiological shifts in the NVU and neural-glia networks after ICH. In addition, potential targets for ICH therapy are discussed in this review. Beyond cerebral blood flow, the NVU also plays an important role in protecting neurons, maintaining central nervous system (CNS) homeostasis, coordinating neuronal activity among supporting cells, forming and maintaining the blood-brain barrier (BBB), and regulating neuroimmune responses. During ICH, NVU dysfunction is induced, along with neuronal cell death, microglia and astrocyte activation, endothelial cell (EC) and tight junction (TJ) protein damage, and BBB disruption. In addition, it has been shown that certain targets and candidates can improve ICH-induced secondary brain injury based on an NVU and neural-glia framework. Moreover, therapeutic approaches and strategies for ICH are discussed.

Linking Labile Heme with Thrombosis

Thrombosis is one of the leading causes of death worldwide. As such, it also occurs as one of the major complications in hemolytic diseases, like hemolytic uremic syndrome, hemorrhage and sickle cell disease. Under these conditions, red blood cell lysis finally leads to the release of large amounts of labile heme into the vascular compartment. This, in turn, can trigger oxidative stress and proinflammatory reactions. Moreover, the heme-induced activation of the blood coagulation system was suggested as a mechanism for the initiation of thrombotic events under hemolytic conditions. Studies of heme infusion and subsequent thrombotic reactions support this assumption. Furthermore, several direct effects of heme on different cellular and protein components of the blood coagulation system were reported. However, these effects are controversially discussed or not yet fully understood. This review summarizes the existing reports on heme and its interference in coagulation processes, emphasizing the relevance of considering heme in the context of the treatment of thrombosis in patients with hemolytic disorders.

Mechanism of Ferroptosis and Its Relationships With Other Types of Programmed Cell Death: Insights for Potential Interventions After Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is a fatal cerebrovascular disease with high morbidity and mortality, for which no effective therapies are currently available. Brain tissue damage caused by ICH is mediated by a newly identified form of non-apoptotic programmed cell death, called ferroptosis. Ferroptosis is characterized by the iron-induced accumulation of lipid reactive oxygen species (ROS), leading to intracellular oxidative stress. Lipid ROS cause damage to nucleic acids, proteins, and cell membranes, eventually resulting in ferroptosis. Numerous biological processes are involved in ferroptosis, including iron metabolism, lipid peroxidation, and glutathione biosynthesis; therefore, iron chelators, lipophilic antioxidants, and other specific inhibitors can suppress ferroptosis, suggesting that these modulators are beneficial for treating brain injury due to ICH. Accumulating evidence indicates that ferroptosis differs from other types of programmed cell death, such as necroptosis, apoptosis, oxytosis, and pyroptosis, in terms of ultrastructural characteristics, signaling pathways, and outcomes. Although several studies have emphasized the importance of ferroptosis due to ICH, the detailed mechanism underlying ferroptosis remains unclear. This review summarizes the available evidence on the mechanism underlying ferroptosis and its relationship with other types of cell death, with the aim to identify therapeutic targets and potential interventions for ICH.

Potential therapeutic targets for intracerebral hemorrhage-associated inflammation: An update

Intracerebral hemorrhage (ICH) is a subtype of stroke with high mortality and disability but no specific or effective treatment. In the last two decades, much has been learned about the pathologic mechanisms of ICH. It is now known that after ICH onset, immune and inflammatory responses contribute to blood-brain barrier disruption, edema development, and cell death processes, jointly resulting in secondary brain injury. However, the translation of potential therapies from preclinical to clinical success has been disappointing. With the development of new laboratory technology, recent progress has been made in the understanding of ICH pathomechanisms, and promising therapeutic targets have been identified. This review provides an update of recent progress on ICH and describes the prospects for further preclinical studies in this field. Our goal is to discuss new therapeutic targets and directions for the treatment of ICH and promote the effective transformation from preclinical to clinical trials.

Prognostic Factors for Cognitive Recovery Beyond Early Poststroke Cognitive Impairment (PSCI): A Prospective Cohort Study of Spontaneous Intracerebral Hemorrhage

Background: Poststroke cognitive impairment (PSCI) has been increasingly recognized in patients, but some stroke survivors appear to show cognitive improvement beyond the acute stage. The risk factors associated with cognitive recovery after spontaneous intracerebral hemorrhage (ICH) onset have not yet been sufficiently investigated in prospective studies.

Objective: We aimed to identify the trajectory of post-ICH cognitive impairment and the association of potential prognostic factors with follow-up cognitive recovery beyond early PSCI.

Methods: In this stroke center-based cohort study, 141 consecutive dementia-free patients with spontaneous ICH were included and underwent Montreal Cognitive Assessment (MoCA) evaluation for cognitive function at baseline (within 2 weeks of ICH onset) and the shortened MoCA (short-MoCA) at a 6-month follow-up. To explore the prognostic factors associated with trajectory of cognition after an ICH onset, we adjusted for demographic and vascular risk factors, using multivariate logistic regression analysis.

Results: Of the 141 ICH patients, approximately three quarters (106/141) were diagnosed with early PSCI (MoCA score <26) within 2 weeks of ICH onset. The multiple logistic regression indicated independent positive associations between risk of early PSCI and dominant-hemisphere hemorrhage [odd's ratio (OR): 8.845 (3.347–23.371); P < 0.001], mean corpuscular volume (MCV) [OR: 1.079 (1.002–1.162); P = 0.043], admission systolic blood pressure (sBP) [OR: 1.021 (1.005–1.038); P = 0.012]. Furthermore, 36% (33/90) of ICH survivors who had early PSCI exhibited cognitive recovery at the 6-month follow-up. After examining potential predictors through multiple linear regression based on stepwise, there were independent negative associations between cognitive recovery and dominant hemisphere hemorrhage [OR: 6.955 (1.604–30.162); P < 0.01], lobar ICH [OR: 8.363 (1.479–47.290); P = 0.016], years of education ≤ 9 [OR: 5.145 (1.254–21.105); P = 0.023], and MCV [OR: 1.660 (1.171–2.354); P = 0.004]. Baseline cognitive performance in the domains of visuospatial/executive function, attention, orientation, and language showed positive correlations with cognitive improvement (P < 0.05).

Conclusion: In this cohort study of dementia-free survivors of ICH, our results show that one in three early PSCI survivors exhibit cognitive recovery, in relation to dominant-hemisphere hematoma, lobar ICH, educational history, and MCV levels. Future clinical trials including ICH survivors with cognitive dysfunction should assess these factors.

Ferroptosis as an emerging target in inflammatory diseases

Cell survival or death is one critical issue in inflammatory responses. Ferroptosis, which is characterized by iron-dependent lethal lipid peroxidation, has been found to participate in the development of cancers, degenerative brain diseases and ischemia-reperfusion injuries. Incorporation of polyunsaturated fatty acids (PUFAs) into cellular membranes represents a vulnerability to invasion of microbials and sterile stimuli. In addition, the competition for iron in the battle between microbials and host cells underlies infection development. Although host cells have been equipped with complex antioxidant systems to combat lethal accumulation of lipid peroxidation, emerging evidence suggests several pathogens may target PUFAs in the cell membrane, and manipulate ferroptosis as a way for pathogen propagation. Moreover, ferroptosis takes part in the progression of sterile inflammations, such as cigarette smoke-induced chronic obstructive pulmonary disease, stroke and ischemia-reperfusion injuries. As iron-dependent oxidative stress and lipid peroxidation are common features for ferroptosis and inflammatory diseases, underlying mechanisms linking such pathological conditions will be discussed in this review. Progress in the research of ferroptosis may shed more light on the etiology and treatment of inflammatory diseases.

What Is Next in This "Age" of Heme-Driven Pathology and Protection by Hemopexin? An Update and Links with Iron

This review provides a synopsis of the published literature over the past two years on the heme-binding protein hemopexin (HPX), with some background information on the biochemistry of the HPX system. One focus is on the mechanisms of heme-driven pathology in the context of heme and iron homeostasis in human health and disease. The heme-binding protein hemopexin is a multi-functional protectant against hemoglobin (Hb)-derived heme toxicity as well as mitigating heme-mediated effects on immune cells, endothelial cells, and stem cells that collectively contribute to driving inflammation, perturbing vascular hemostasis and blood–brain barrier function. Heme toxicity, which may lead to iron toxicity, is recognized increasingly in a wide range of conditions involving hemolysis and immune system activation and, in this review, we highlight some newly identified actions of heme and hemopexin especially in situations where normal processes fail to maintain heme and iron homeostasis. Finally, we present preliminary data showing that the cytokine IL-6 cross talks with activation of the c-Jun N-terminal kinase pathway in response to heme-hemopexin in models of hepatocytes. This indicates another level of complexity in the cell responses to elevated heme via the HPX system when the immune system is activated and/or in the presence of inflammation.