CD47 blocking antibody accelerates hematoma clearance and alleviates hydrocephalus after experimental intraventricular hemorrhage.
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SUBMITTER: Ye F
PROVIDER: S-EPMC8197745 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Background and Purpose- Our previous studies found that erythrocyte CD47 has a role in regulating hematoma resolution following experimental intracerebral hemorrhage (ICH). The current study examined whether or not a CD47 blocking antibody enhances hematoma clearance in a mouse ICH. Methods- ICH was induced by intracaudate injection of autologous blood in adult C57BL/6 mice. Mice had an ICH or ICH with CD47 blocking antibody or IgG coinjection. In subgroups of CD47 blocking antibody-treated mice, clodronate (to deplete microglia/macrophages) or control liposomes were coinjected. The effects of CD47 blocking antibody on ICH-induced brain injury were also tested in both males and females. Mice had magnetic resonance imaging to examine clot volume, iron deposition, brain swelling, and brain tissue loss. Behavioral tests were performed in all mice, and brains were harvested for brain immunohistochemistry. Results- In male mice, CD47 blocking antibody speeded up hematoma/iron clearance by macrophages/microglia and reduced ICH-induced brain swelling, neuronal loss, and neurological deficits. In contrast, clodronate liposome-induced microglia/macrophage depletion caused more severe brain swelling, neuronal loss, and functional deficits. In addition, similar injury severity in males and females was found in IgG control group and CD47 blocking antibody was also effective in females. Conclusions- Blocking CD47 in the hematoma speeded hematoma clearance and reduced brain injury after ICH suggesting it could be a treatment for ICH patients with surgical clot removal.
| S-EPMC6538472 | biostudies-literature
Project description:Background and Purpose- Preterm neonates with intraventricular hemorrhage (IVH) are at risk for posthemorrhagic hydrocephalus and poor neurological outcomes. Iron has been implicated in ventriculomegaly, hippocampal injury, and poor outcomes following IVH. We hypothesized that levels of cerebrospinal fluid blood breakdown products and endogenous iron clearance proteins in neonates with IVH differ from those of neonates with IVH who subsequently develop posthemorrhagic hydrocephalus. Methods- Premature neonates with an estimated gestational age at birth <30 weeks who underwent lumbar puncture for clinical evaluation an average of 2 weeks after birth were evaluated. Groups consisted of controls (n=16), low-grade IVH (grades I-II; n=4), high-grade IVH (grades III-IV; n=6), and posthemorrhagic hydrocephalus (n=9). Control subjects were preterm neonates born at <30 weeks' gestation without brain abnormality or hemorrhage on cranial ultrasound, who underwent lumbar puncture for clinical purposes. Cerebrospinal fluid hemoglobin, total bilirubin, total iron, ferritin, ceruloplasmin, transferrin, haptoglobin, and hemopexin were quantified. Results- Cerebrospinal fluid hemoglobin levels were increased in posthemorrhagic hydrocephalus compared with high-grade IVH (9.45 versus 6.06 µg/mL, P<0.05) and cerebrospinal fluid ferritin levels were increased in posthemorrhagic hydrocephalus compared with controls (511.33 versus 67.08, P<0.01). No significant group differences existed for the other cerebrospinal fluid blood breakdown and iron-handling proteins tested. We observed positive correlations between ventricular enlargement (frontal occipital horn ratio) and ferritin (Pearson r=0.67), hemoglobin (Pearson r=0.68), and total bilirubin (Pearson r=0.69). Conclusions- Neonates with posthemorrhagic hydrocephalus had significantly higher levels of hemoglobin than those with high-grade IVH. Levels of blood breakdown products, hemoglobin, ferritin, and bilirubin correlated with ventricular size. There was no elevation of several iron-scavenging proteins in cerebrospinal fluid in neonates with posthemorrhagic hydrocpehalus, indicative of posthemorrhagic hydrocephalus as a disease state occurring when endogenous iron clearance mechanisms are overwhelmed.
| S-EPMC7253327 | biostudies-literature
Project description:Background and purposeThrombolytic efficacy of intraventricular rtPA for acute intraventricular hemorrhage may depend on hematoma composition. We assessed whether hematoma Hounsfield unit quantification informs intraventricular hemorrhage clearance after intraventricular rtPA.Materials and methodsSerial NCCT was performed on 52 patients who received intraventricular rtPA as part of the Clot Lysis Evaluation of Accelerated Resolution of Intraventricular Hemorrhage trial and 12 controls with intraventricular hemorrhage, but no rtPA treatment. A blinded investigator calculated Hounsfield unit values for intraventricular hemorrhage volumes on admission (t0), days 3-4 (t1), and days 6-9 (t2). Controls were matched uniquely to 12 rtPA-treated patients for comparison.ResultsMedian intraventricular hemorrhage volume on admission for patients treated with intraventricular rtPA was 31.9 mL (interquartile range, 34.1 mL), and it decreased to 4.9 mL (interquartile range, 14.5 mL) (t2). Mean (±standard error of the mean) Hounsfield unit for intraventricular hemorrhage was 52.1 (0.59) at t0 and decreased significantly to 50.1 (0.63) (t1), and to 45.1 (0.71) (t2). Total intraventricular hemorrhage Hounsfield unit count was significantly correlated with intraventricular hemorrhage volume at all time points (t0: P = .002; t1: P < .001; t2: P < .001). On serologic and CSF analysis at t0, only higher CSF protein was positively correlated with intraventricular hemorrhage Hounsfield units (P = .03). In 24 matched patients treated with rtPA and controls, total intraventricular hemorrhage Hounsfield units were significantly lower in patients treated with rtPA at t2 (P = .02). Higher Hounsfield unit quantification of fourth ventricle hematomas independently predicted slower clearance of this ventricle (95% CI, 0.02-0.14; P = .02), along with higher intraventricular hemorrhage volume (95% CI, 0.02-0.41; P = .03) and lower CSF protein levels (95% CI, -0.003 to -0.002; P < .001).ConclusionsIntraventricular hemorrhage Hounsfield unit counts decrease significantly in the acute phase and to a greater extent with intraventricular rtPA treatment. Intraventricular hemorrhage Hounsfield units are correlated significantly with CSF protein and not with serum erythrocyte or platelet concentrations. Hounsfield unit counts may reflect intraventricular hemorrhage clot composition and rtPA sensitivity.
| S-EPMC7968774 | biostudies-literature
Project description:Background and Purpose- Enhancement of erythrophagocytosis by macrophages in a timely manner can limit the toxic effects of erythrocyte metabolites and promote brain recovery after intracerebral hemorrhage (ICH). In the current study, we investigated the therapeutic effect of retinoid X receptor agonist, bexarotene, in facilitating erythrophagocytosis and neurobehavioral recovery in 2 mouse models of ICH. Methods- Bone marrow-derived macrophages and fluorescently labeled erythrocytes were used to study erythrophagocytosis in vitro with phenotypic changes quantified by gene expression. ICH was modeled in vivo using intrastriatal autologous blood and collagenase injection in mice with and without bexarotene treatment beginning 3 hours after ICH. In vivo phagocytosis, ability and hematoma clearance were evaluated by erythrophagocytosis assays, flow cytometry, and histological analysis. Neurological deficits and functional recovery were also quantified. Results- Bexarotene increased macrophage expression of phagocytosis receptors and erythrophagocytosis and reduced macrophage TNF (tumor necrosis factor) production in vitro. In vivo, bexarotene treatment enhanced erythrophagocytosis, reduced hematoma volume, and ultimately improved neurological recovery after ICH in 2 distinct models of ICH. Conclusions- Bexarotene administration is beneficial for recovery after ICH by enhancing hemorrhage phagocytosis, modulating macrophage phenotype, and improving functional recovery.
| S-EPMC7135897 | biostudies-literature
Project description:Background and purposeEnhancing hematoma clearance through phagocytosis may reduce brain injury after intracerebral hemorrhage. In the current study, we investigated the role of cluster of differentiation 47 (CD47) in regulating erythrophagocytosis and brain injury after intracerebral hemorrhage in nude mice.MethodsThis study was in 2 parts. First, male adult nude mice had an intracaudate injection of 30 μL saline, blood from male adult wild-type (WT) mice, or blood from CD47 knockout mice. Second, mice had an intracaudate injection of 30 μL CD47 knockout blood with clodronate or control liposomes. Clodronate liposomes were also tested in saline-injected mice. All mice then had magnetic resonance imaging to measure hematoma size and brain swelling. Brains were used for immunohistochemistry and Western blot.ResultsErythrophagocytosis occurred in and around the hematoma. Injection of CD47 knockout blood resulted in quicker clot resolution, less brain swelling, and less neurological deficits compared with wild-type blood. Higher brain heme oxygenase-1 levels and more microglial activation (mostly M2 polarized microglia) at day 3 were found after CD47 knockout blood injection. Co-injection of clodronate liposomes, to deplete phagocytes, caused more severe brain swelling and less clot resolution.ConclusionsThese results indicated that CD47 has a key role in hematoma clearance after intracerebral hemorrhage.
| S-EPMC4729651 | biostudies-literature
Project description:ImportanceIntraventricular thrombolysis reduces intraventricular hemorrhage (IVH) volume in patients with spontaneous intracerebral hemorrhage (ICH), but it is unclear if a similar association with parenchymal ICH volume exists.ObjectiveTo evaluate the association between intraventricular alteplase use and ICH volume as well as the association between a change in parenchymal ICH volume and long-term functional outcomes.Design, setting, and participantsThis cohort study was a post hoc exploratory analysis of data from the Clot Lysis: Evaluating Accelerated Resolution of Intraventricular Hemorrhage phase 3 randomized clinical trial with blinded outcome assessments. Between September 1, 2009, and January 31, 2015, patients with ICH and IVH were randomized to receive either intraventricular alteplase or normal saline via an external ventricular drain. Participants with primary IVH were excluded. Data analyses were performed between January 1 and June 30, 2021.ExposureRandomization to receive intraventricular alteplase.Main outcomes and measuresThe primary outcome was the change in parenchymal ICH volume between the hematoma stability and end-of-treatment computed tomography scans. Secondary outcomes were a modified Rankin Scale score higher than 3 and mortality, both of which were assessed at 6 months. The association between alteplase and change in parenchymal ICH volume was assessed using multiple linear regression, whereas the associations between change in parenchymal ICH volume and 6-month outcomes were assessed using multiple logistic regression. Prespecified subgroup analyses were performed for baseline IVH volume, admission ICH volume, and ICH location.ResultsA total of 454 patients (254 men [55.9%]; mean [SD] age, 59 [11] years) were included in the study. Of these patients, 230 (50.7%) were randomized to receive alteplase and 224 (49.3%) to receive normal saline. The alteplase group had a greater mean (SD) reduction in parenchymal ICH volume compared with the saline group (1.8 [0.2] mL vs 0.4 [0.1] mL; P < .001). In the primary analysis, alteplase use was associated with a change in the parenchymal ICH volume in the unadjusted analysis per 1-mL change (β, 1.37; 95% CI, 0.92-1.81; P < .001) and in multivariable linear regression analysis that was adjusted for demographic characteristics, stability ICH and IVH volumes, ICH location, and time to first dose of study drug per 1-mL change (β, 1.20; 95% CI, 0.79-1.62; P < .001). In the secondary analyses, no association was found between change in parenchymal ICH volume and poor outcome (odds ratio [OR], 0.97; 95% CI 0.87-1.10; P = .64) or mortality (OR, 0.97; 95% CI 0.99-1.08; P = .59). Similar results were observed in the subgroup analyses.Conclusions and relevanceThis study found that intraventricular alteplase use in patients with a large IVH was associated with a small reduction in parenchymal ICH volume, but this association did not translate into improved functional outcomes or mortality. Intraventricular thrombolysis should be examined in patients with moderate to large ICH with IVH, especially in a thalamic location.
| S-EPMC8642781 | biostudies-literature
Project description:BackgroundIntraventricular hemorrhage (IVH) after intracerebral hemorrhage (ICH) is a strong independent predictor of poor outcomes. Although the location and volume of ICH are associated with IVH, our knowledge concerning the mechanism of IVH after ICH is still limited. This study aimed to investigate the relationship between hematoma morphology and IVH in patients with supratentorial deep ICH.MethodsWe retrospectively analyzed adult patients (aged ≥18 years) with spontaneous supratentorial deep ICH who underwent computed tomography (CT) within 48 h after ICH symptom onset in Peking University First Hospital between January 2017 and August 2022. We collected the clinical and imaging data of the patients and assessed hematoma morphology using several quantitative radiological parameters including hematoma volume, sphericity index, A/B ratio (A: the largest area of hematoma; B: the largest diameter 90° to A on the same slice), and our newly proposed largest diameter-midline angle (LMA). Multivariable logistic regression analysis was used to analyze the relationship between these parameters and the presence of IVH on the initial CT scan.ResultsAmong 114 patients with spontaneous supratentorial deep ICH, 41 (36.0%) had IVH. In patients with IVH, the sphericity index was lower than that in individuals without IVH, while the LMA was larger. Multivariate logistic regression analysis showed that sphericity index [0.1-unit odds ratio (OR) =0.252; 95% CI: 0.089-0.709; P=0.009] and the LMA (10-unit OR =1.281; 95% CI: 1.007-1.630; P=0.04) were independently associated with the presence of IVH in patients with supratentorial deep ICH. Univariate analyses showed that hematoma volume, A/B ratio, sphericity index, and the LMA were significantly associated with poor outcomes at discharge.ConclusionsTwo quantitative parameters of hematoma morphology, sphericity index and the LMA, were significantly associated with the presence of IVH in patients with supratentorial deep ICH. Further prospective studies with larger sample sizes are needed to validate our results.
| S-EPMC10585571 | biostudies-literature
Project description:Background and Purpose- Our recent study demonstrated that release of Prx2 (peroxiredoxin 2) from red blood cells (RBCs) is involved in the inflammatory response and brain injury after intracerebral hemorrhage. The current study investigated the role of extracellular Prx2 in hydrocephalus development after experimental intraventricular hemorrhage. Methods- There were 4 parts in this study. First, Sprague-Dawley rats received an intraventricular injection of lysed RBC or saline and were euthanized at 1 hour for Prx2 measurements. Second, rats received an intraventricular injection of Prx2, deactivated Prx2, or saline. Third, lysed RBC was coinjected with conoidin A, a Prx2 inhibitor, or vehicle. Fourth, rats received Prx2 injection and were treated with minocycline or saline (i.p.). The effects of Prx2 and the inhibitors were examined using magnetic resonance imaging assessing ventriculomegaly, histology assessing ventricular wall damage, and immunohistochemistry to assess inflammation, particularly at the choroid plexus. Results- Intraventricular injection of lysed RBC resulted in increased brain Prx2 and hydrocephalus. Intraventricular injection of Prx2 alone caused hydrocephalus, ventricular wall damage, activation of choroid plexus epiplexus cells (macrophages), and an accumulation of neutrophils. Conoidin A attenuated lysed RBC-induced injury. Systemic minocycline treatment reduced the epiplexus cell activation and hydrocephalus induced by Prx2. Conclusions- Prx2 contributed to the intraventricular hemorrhage-induced hydrocephalus, probably by inducing inflammatory responses in choroid plexus and ventricular wall damage.
| S-EPMC7192237 | biostudies-literature
Project description:BackgroundNeonatal germinal matrix hemorrhage/intraventricular hemorrhage is common and often results in hydrocephalus. The pathogenesis of posthemorrhagic hydrocephalus is not fully understood.ObjectiveTo explore the potential role of hemoglobin and iron released after hemorrhage.MethodsArtificial cerebrospinal fluid (aCSF), hemoglobin, or iron was injected into the right lateral ventricle of postnatal day-7 Sprague Dawley rats. Ventricle size, heme oxygenase-1 (HO-1) expression, and the presence of iron were evaluated 24 and 72 hours after injection. A subset of animals was treated with an iron chelator (deferoxamine) or vehicle for 24 hours after hemoglobin injection, and ventricle size and cell death were evaluated.ResultsIntraventricular injection of hemoglobin and iron resulted in ventricular enlargement at 24 hours compared with the injection of aCSF. Protoporphyrin IX, the iron-deficient immediate heme precursor, did not result in ventricular enlargement after injection into the ventricle. HO-1, the enzyme that releases iron from heme, was increased in the hippocampus and cortex of hemoglobin-injected animals at 24 hours compared with aCSF-injected controls. Treatment with an iron chelator, deferoxamine, decreased hemoglobin-induced ventricular enlargement and cell death.ConclusionIntraventricular injection of hemoglobin and iron can induce hydrocephalus. Treatment with an iron chelator reduced hemoglobin-induced ventricular enlargement. This has implications for the pathogenesis and treatment of posthemorrhagic hydrocephalus.AbbreviationsaCSF, artificial cerebrospinal fluidDAB, 3,3'-diaminobenzidine-4HClGMH-IVH, germinal matrix hemorrhage/intraventricular hemorrhageHO-1, heme oxygenase-1ICH, intracerebral hemorrhagePBS, phosphate-buffered salineSVZ, subventricular zoneTBST, tris-buffered saline with Tween 20.
| S-EPMC4237659 | biostudies-literature
Project description:Background and objectiveThe aim of this study was to evaluate the impact of radiographic cerebral small vessel disease (CSVD) on the severity of acute intracerebral hemorrhage (ICH) as measured by: ICH volume, hematoma expansion, and extension of intraventricular hemorrhage (IVH).MethodsCSVD was determined on baseline computed tomography (CT) scans of patients from the Ethnic and Racial Variations of Intracerebral Hemorrhage study through the extent of leukoaraiosis and cerebral atrophy using visual rating scales. The associations of leukoaraiosis and atrophy with ICH volume, hematoma expansion, IVH presence, and severity of IVH were tested using multivariable regression models. Secondary analyses were stratified by hemorrhage location. Bonferroni correction was applied to correct for multiple testing.ResultsA total of 2579 patients (mean age 61.7 years, 59% male) met inclusion criteria. Median ICH volume was 10.5 (Interquartile range [IQR] 4.0-25.3) mL. IVH was detected in 971 patients (38%). Neither leukoaraiosis nor atrophy was associated with hematoma expansion. Increasing grades of leukoaraiosis were associated with increased risk of IVH in a dose-dependent manner, while cerebral atrophy was inversely associated with IVH (both P for trend < 0.001). Increasing grades of global atrophy were dose-dependently associated with lower ICH volumes (ß (95% Confidence Interval [CI]) - 0.30[- 0.46, - 0.14], - 0.33[- 0.49, - 0.17], - 0.40[- 0.60, - 0.20], and - 0.54[- 0.76, - 0.32], for grades 1, 2, 3 and 4 compared to 0; all P < 0.001). The associations of leukoaraiosis with ICH volume were consistent with those of atrophy, albeit not meeting statistical significance.ConclusionsLeukoaraiosis and cerebral atrophy appear to have opposing associations with ICH severity. Cerebral atrophy correlates with smaller ICH volume and decreased risk and severity of IVH, while leukoaraiosis is associated with increased risk of IVH. Whether these observations reflect overlapping or divergent underlying mechanisms requires further study.
| S-EPMC7082383 | biostudies-literature