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Rationale : The vagus nerve, which connects the brain and gastrointestinal tract, helps to maintain immune balance in the intestines. Gut-specific integrins, on the other hand, help to keep immune cells in the intestines. Since immune cells from outside the intestines can significantly affect the outcome of strokes, we investigated how immune cells from the intestines affect the immune response in the brain during intracerebral hemorrhage (ICH). Methods : We aimed to examine the impact of vagal innervation on intestinal immunocyte trafficking and its influence on ICH outcomes using Kikume Green-Red (KikGR) and wildtype (WT) mice, with or without prior subdiaphragmatic vagotomy (SDV). Furthermore, we sought to elucidate the regulatory effects of vagal innervation on intestinal immunocyte trafficking by activating α7 nicotinic acetylcholine receptors (α7nAChR) in WT mice that underwent ICH after SDV. Additionally, we explored the potential intermediary role of gut-selective integrins in cholinergic transmitters-mediated intestinal immunocyte trafficking. Our methodology encompassed in vivo fluorescence imaging, flow cytometry, Western blotting, immunofluorescence staining, histopathology, and behavioral assessments to evaluate the outcomes. Results : Our findings reveal that during the acute phase of ICH, intestinal immunocytes migrated to various anatomical locations, including the circulation, hemorrhagic brain, meninges, and deep cervical lymph nodes. Pertinently, SDV resulted in diminished expression of α4β7 and αEβ7 integrins on immunocytes, leading to heightened intestinal immunocyte trafficking and exacerbated ICH outcomes. Conversely, the administration of α7nAChR agonists countered the adverse effects of vagotomy on α4β7 and αEβ7 integrin expression, thereby constraining the migration of immune cells from the intestines after ICH. The implication of α4β7 and αEβ7 integrins in this setting was supported by the ineffective influence of α7nAChR agonists on the trafficking of intestinal immunocytes enhanced by administering beta-7 integrin antagonists, such as etrolizumab. It was further supported by the exacerbated ICH outcomes by administering beta-7 integrin antagonists like etrolizumab alone. Conclusion : The identification of vagus nerve-mediated modulation of α4β7 and αEβ7 integrin expression in the trafficking of immune cells within the intestinal tract holds significant implications. This discovery presents new opportunities for developing therapeutic interventions for ICH and stimulates further investigation in this area., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Despite stroke being one of the major and increasing burdens to global health, therapeutic interventions in intracerebral haemorrhage (ICH) continue to be a challenge. Existing treatment methods, such as surgery and conservative treatment have shown limited efficacy in improving the prognosis of ICH. However, more and more studies show that exploring the specific process of immune response after ICH and taking corresponding immunotherapy may have a definite significance to improve the prognosis of cerebral haemorrhage. Therefore, immune interventions are currently under consideration as therapeutic interventions in the ICH. In this review, we aim to clarify unique immunological features of stroke, and consider the evidence for immune interventions. In acute ICH, activation of glial cells and cell death products trigger an inflammatory cascade that damages vessels and the parenchyma within minutes to hours of the haemorrhage. Immune interventions that ameliorate brain inflammation, vascular permeability and tissue oedema should be administered promptly to reduce acute immune destruction and avoid subsequent immunosuppression. A deeper understanding of the immune mechanisms involved in ICH is likely to lead to successful immune interventions.

Stroke has emerged as the primary cause of disability and death globally in recent years. Intracerebral hemorrhage (ICH), a particularly severe kind of stroke, is occurring in an increasing number of people. The two main clinical treatments for ICH now in use are conservative pharmaceutical therapy and surgical intervention, both of which have risks and drawbacks. Consequently, it is crucial to look into the pathophysiology of ICH and consider cutting-edge therapeutic approaches. Recent research has revealed that pyroptosis is a newly identified type of cell death distinguished by the break of the cell membrane and the discharge of pro-inflammatory substances through different routes. Following ICH, glial cells experience pyroptosis, which worsens neuroinflammation. Hence, the onset and progression of ICH are strongly linked to pyroptosis, which is facilitated by different inflammasomes. It is essential to conduct a comprehensive investigation of ICH damage processes and uncover new targets for treatment. The impact and function of pyroptosis in ICH, as well as the activation and regulation of inflammasomes and their mediated pyroptosis pathways will be fully discussed in this review., Competing Interests: Declaration of Competing Interest The authors whose names are listed immediately below certify that they have NO afiliations with or involvement in any organization or entity with any inancial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership,employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-inancial interest (such as personal or professional relationships, afiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Microglia are important innate immune cells in the brain, and a rich diversity of subtypes has recently been discovered that expand beyond the traditional classification of traditional M1 (pro-inflammatory) and M2 (anti-inflammatory) classifications. Intracerebral hemorrhage (ICH) is a devastating form of stroke, and the understanding of its later-stage pathological mechanisms remains incomplete. In this study, through the analysis of single-cell transcripts from mice brains 14 days post-ICH, three disease-associated expression patterns of microglia were identified. These include a lipid metabolism and phagocytosis phenotype reminiscent of Disease-Associated Microglia (DAM) initially discovered in Alzheimer's disease models, a phenotype associated with angiogenesis, and a relatively independent phenotype similar to the pro-inflammatory M1 state. These findings were further validated through immunofluorescence in both mouse and human specimens. In addition, analysis of single-cell transcripts from mice brains 3 days post-ICH suggested that microglia involved in lipid metabolism and phagocytosis likely emerge from early proliferating populations. Given the distinct origins and phenotypic characteristics of pro-inflammatory and reparative microglia, interventions targeting these cells hold the potential to modulate the delicate balance between injury and repair during the pathophysiological process of ICH, highlighting a pivotal direction for future therapeutic strategies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Intracerebral hemorrhage has the characteristics of high morbidity, disability and mortality, which has caused a heavy burden to families and society. Microglia are resident immune cells in the central nervous system, and their activation plays a dual role in tissue damage after intracerebral hemorrhage. The damage in cerebral hemorrhage is embodied in the following aspects: releasing inflammatory factors and inflammatory mediators, triggering programmed cell death, producing glutamate induced excitotoxicity, and destroying blood-brain barrier; The protective effect is reflected in the phagocytosis and clearance of harmful substances by microglia, and the secretion of anti-inflammatory and neurotrophic factors. This article summarizes the function of microglia and its dual regulatory mechanism in intracerebral hemorrhage. In the future, drugs, acupuncture and other clinical treatments can be used to intervene in the activation state of microglia, so as to reduce the harm of microglia., Competing Interests: Declaration of Competing Interest The authors have nothing to declare and have no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Intracerebral hemorrhage (ICH) is a severe stroke subtype with high morbidity, disability, and mortality rates. Currently, no biomarkers for ICH are available for use in clinical practice. We aimed to explore the roles of RNAs in ICH pathogenesis and identify potential diagnostic biomarkers., Methods: We collected 233 individual blood samples from two independent cohorts, including 64 patients with ICH, 59 patients with ischemic stroke (IS), 60 patients with hypertension (HTN) and 50 healthy controls (CTRL) for RNA sequencing. Differentially expressed genes (DEGs) analysis, gene set enrichment analysis (GSEA), and weighted correlation network analysis (WGCNA) were performed to identify ICH-specific modules. The immune cell composition was evaluated with ImmuneCellAI. Multiple machine learning algorithms to select potential biomarkers for ICH diagnosis, and further validated by quantitative real-time polymerase chain reaction (RT-PCR). Receiver operating characteristic (ROC) curve analysis and decision curve analysis (DCA) were performed to evaluate the diagnostic value of the signature for ICH. Finally, we generated M1 and M2 macrophages to investigate the expression of candidate genes., Results: In both cohorts, 519 mRNAs and 131 lncRNAs were consistently significantly differentially expressed between ICH patients and HTN controls. Gene function analysis suggested that immune system processes may be involved in ICH pathology. ImmuneCellAI analysis revealed that the abundances of 11 immune cell types were altered after ICH in both cohorts. WGCNA and GSEA identified 18 immune-related DEGs. Multiple algorithms identified an RNA panel (CKAP4, BCL6, TLR8) with high diagnostic value for discriminating ICH patients from HTN controls, CTRLs and IS patients (AUCs: 0.93, 0.95 and 0.82; sensitivities: 81.3%, 84.4% and 75%; specificities: 100%, 96% and 79.7%, respectively). Additionally, CKAP4 and TLR8 mRNA and protein levels decreased in RAW264.7 M1 macrophages and increased in RAW264.7 M2 macrophages, while BCL6 expression increased in M1 macrophages but not in M2 macrophages, which may provide potential therapeutic targets for ICH., Conclusions: This study demonstrated that the expression levels of lncRNAs and mRNAs are associated with ICH, and an RNA panel (CKAP4, BCL6, TLR8) was developed as a potential diagnostic tool for distinguishing ICH from IS and controls, which could provide useful insight into ICH diagnosis and pathogenesis., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Bai, Liu, Wang, Sun, Wang, Liu, Hao, Zhou, Yuan and Liu.)

Background: Dendritic cells (DCs) regulate the immune response associated with T lymphocytes, but their role in stroke remains unclear. In this study, we investigated the causal relationship between DCs and T-cell response in intracerebral hemorrhage (ICH) by focusing on TLRs (toll-like receptors) that may modulate the function of DCs., Methods: We studied the effects of TLR4, TLR2, and TLR9 on DC-mediated T-cell response and the outcomes of ICH using male C57BL/6 and CD11c-DTx (diphtheria toxin) receptor mice. We administered specific agents intraperitoneally or orally and evaluated the results using flow cytometry, real-time polymerase chain reaction, Western blotting, immunofluorescence staining, histopathology, and behavioral tests., Results: TLR4 and TLR2 activation induces DC maturation and reduces the ratio of regulatory T to T-helper 17 cells in the brain and periphery after ICH. When either of these receptors is activated, it can worsen neuroinflammation and exacerbate ICH outcomes. TLR9 also promotes DC maturation, stabilizing the number of DCs, particularly conventional DCs. TLR9 has the opposite effects on regulatory T/T-helper 17 balance, neuroinflammation, and ICH outcomes compared with TLR4 and TLR2. Upon stimulation, TLR4 and TLR9 may achieve these effects through the p38-MAPK (p38-mitogen-activated protein kinase)/MyD88 (myeloid differentiation primary response gene 88) and indoleamine 2,3-dioxygenase 1 (IDO1)/GCN2 (general control nonderepressible 2) signaling pathways, respectively. DCs act as intermediaries for TLR-mediated T-cell response., Conclusions: TLR-mediated opposing effects of DCs on T-cell response may provide novel strategies to treat ICH., Competing Interests: None.

Secondary injury of cerebral hemorrhage is induced by systemic inflammatory cascades, which are related to perihematomal brain edema, cellular apoptosis, and the disruption of the blood-brain barrier. This study was to specifically elaborate the relationship of circulating/cerebrospinal T lymphocytes and Glasgow Coma Scale (GCS) score at 6 months after intracerebral hemorrhage (ICH). The enrolled patients were divided into 2 groups based on GCS score: the favorable prognosis group (GCS > 12) and unfavorable prognosis group (GCS ≤ 12). T lymphocyte subpopulations were analyzed by flow cytometry. A total of 30 samples of peripheral blood and 17 samples of cerebrospinal fluid were collected and analyzed, including 19 cases and 12 cases in the favorable prognosis group (GCS > 12) respectively. Both CD3+ and CD3+CD4+ T lymphocyte counts on Day 1 after ICH were lower in the peripheral blood of patients with unfavorable prognosis (GCS ≤ 12) (P = .025 and .022, respectively). There were correlation trends between the GCS scores and CD3+ T lymphocyte count (P = .0144), and CD3+CD4+ T lymphocyte count (P = .0135). In cerebrospinal fluid, there was a close correlation between the GCS scores and CD3+CD4+ percentage, CD4+/CD8+ ratio, CD3+ and CD3+CD4+ T lymphocyte counts. The area under the curve of CD4+/CD8+ T lymphocyte ratio was the largest among them (P = .000 and area under the curve = 0.917), with a significantly high specificity and sensitivity (0.917 and 1.000). Based on cerebrospinal fluid samples, the CD4+/CD8+ T lymphocyte ratio on Day 1 after ICH may be a more significant indicator to predict the short-term prognosis at 6 months after ICH., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Recent studies have shown systemic inflammatory response, serum glucose, and serum potassium are associated with poor prognosis in spontaneous intracerebral hemorrhage (SICH). This retrospective study aimed to investigate the association of systemic immune-inflammatory index (SII) and serum glucose-potassium ratio (GPR) with the severity of disease and the poor prognosis of patients with SICH at 3 months after hospital discharge. We reviewed the clinical data of 105 patients with SICH, assessed the extent of their disease using Glasgow Coma Scale score, National Institutes of Health Stroke Scale (NIHSS) score, and hematoma volume, and categorized them into a good prognosis group (0-3 scores) and a poor prognosis group (4-6 scores) based on their mRS scores at 3 months after hospital discharge. Demographic characteristics, clinical, laboratory, and imaging data at admission were compared between the 2 groups, bivariate correlations were analyzed using Spearman's correlation coefficients, multivariate logistic regression analysis was used to determine the independent risk factors for poor prognosis of patients with SICH, and finally, SII, GPR, and platelet/lymphocyte ratio (PLR) were examined using the subject's work characteristics (ROC) curve, lymphocyte/monocyte ratio (LMR), and neutrophil/lymphocyte ratio (NLR) for their predictive efficacy for poor prognosis. Patients in the poor prognosis group had significantly higher SII and serum GPR than those in the good prognosis group, and Spearman analysis showed that SII and serum GPR were significantly correlated with the admission Glasgow Coma Scale score as well as the NIHSS score and that SII and GPR increased with the increase in mRS score. Multivariate logistic regression analysis showed that admission NIHSS score, hematoma volume SII, GPR, NLR, and PLR were independently associated with poor patient prognosis. Analysis of the subjects' work characteristic curves showed that the areas under the SII, GPR, NLR, PLR, LMR, and coSII-GPR curves were 0.838, 0.837, 0.825, 0.718, 0.616, and 0.883. SII and GRP were significantly associated with disease severity and short-term prognosis in SICH patients 3 months after discharge, and SII and GPR had better predictive value compared with NLR, PLR, and LMR. In addition, coSII-GPR, a joint indicator based on SII and GPR, can improve the predictive accuracy of poor prognosis 3 months after discharge in patients with SICH., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Aims: Intracerebral hemorrhage (ICH) is a condition that arises due to the rupture of cerebral blood vessels, leading to the flow of blood into the brain tissue. One of the pathological alterations that occurs during an acute ICH is an impairment of the blood-brain barrier (BBB), which leads to severe perihematomal edema and an immune response., Discussion: A complex interplay between the cells of the BBB, for example, pericytes, astrocytes, and brain endothelial cells, with resident and infiltrating immune cells, such as microglia, monocytes, neutrophils, T lymphocytes, and others accounts for both damaging and protective mechanisms at the BBB following ICH. However, the precise immunological influence of BBB disruption has yet to be richly ascertained, especially at various stages of ICH., Conclusion: This review summarizes the changes in different cell types and molecular components of the BBB associated with immune-inflammatory responses during ICH. Furthermore, it highlights promising immunoregulatory therapies to protect the integrity of the BBB after ICH. By offering a comprehensive understanding of the mechanisms behind BBB damage linked to cellular and molecular immunoinflammatory responses after ICH, this article aimed to accelerate the identification of potential therapeutic targets and expedite further translational research., (© 2024 The Author(s). CNS Neuroscience & Therapeutics published by John Wiley & Sons Ltd.)

Objective: We sought to determine whether the initial Systemic Inflammatory Response Index (SIRI) was associated with pneumonia after spontaneous intracerebral hemorrhage (SICH) in hospitalized patients., Patients and Methods: Patients with SICH admitted to Taizhou People's Hospital between January 2019 and December 2021 were retrospectively analyzed. Baseline variables were compared between stroke-associated pneumonia (SAP) and non-SAP groups. Multivariable logistic regression analyses were utilized to calculate the relationship between SIRI and SAP risk., Results: Of 495 patients included in this research, 192 (38.79%) developed SAP ultimately. The SIRI values exhibited the highest area under the curve value for SAP incidence (area under the curve = 0.736, 95% CI: 0.692-0.781), with respective sensitivity and specificity values of 0.646 and 0.749 at the optimal cutoff threshold of 2.53. In multivariate analysis, high SIRI (≥2.53) was a significant independent predictor of post-SICH SAP even after controlling for other possible confounding variables (odds ratio: 5.11, 95% CI: 2.89-9.04, P < 0.001). According to the restricted cubic splines model, SAP risk increases as SIRI increases., Conclusions: We observed that SIRI values may offer high diagnostic utility as a predictor of SAP risk among patients with SICH during the early stages of the disease., Competing Interests: The authors declare no conflict of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Microglia play a pivotal role in the neuroinflammatory response after brain injury, and their proliferation is dependent on colony-stimulating factors. In the present study, we investigated the effect of inhibiting microglia proliferation on neurological damage post intracerebral hemorrhage (ICH) in a mouse model, an aspect that has never been studied before. Using a colony-stimulating factor-1 receptor antagonist (GW2580), we observed that inhibition of microglia proliferation significantly ameliorated neurobehavioral deficits, attenuated cerebral edema, and reduced hematoma volume after ICH. This intervention was associated with a decrease in pro-inflammatory factors in microglia and an increased infiltration of peripheral regulatory CD8 + CD122+ T cells into the injured brain tissue. The CXCR3/CXCL10 axis is the mechanism of brain homing of regulatory CD8 + CD122+ T cells, and the high expression of IL-10 is the hallmark of their synergistic anti-inflammatory effect with microglia. And activated astrocytes around the insult site are a prominent source of CXCL10. Thus, inhibition of microglial proliferation offers a new perspective for clinical translation. The cross-talk between multiple cells involved in the regulation of the inflammatory response highlights the comprehensive nature of neuroimmunomodulation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Perihematomal edema (PHE) after post-intracerebral hemorrhage (ICH) has complex pathophysiological mechanisms that are poorly understood. The complicated immune response in the post-ICH brain constitutes a crucial component of PHE pathophysiology. In this study, we aimed to characterize the transcriptional profiles of immune cell populations in human PHE tissue and explore the microscopic differences between different types of immune cells., Methods: 9 patients with basal ganglia intracerebral hemorrhage (hematoma volume 50-100 ml) were enrolled in this study. A multi-stage profile was developed, comprising Group1 (n = 3, 0-6 h post-ICH, G1), Group2 (n = 3, 6-24 h post-ICH, G2), and Group3 (n = 3, 24-48 h post-ICH, G3). A minimal quantity of edematous tissue surrounding the hematoma was preserved during hematoma evacuation. Single cell RNA sequencing (scRNA-seq) was used to map immune cell populations within comprehensively resected PHE samples collected from patients at different stages after ICH., Results: We established, for the first time, a comprehensive landscape of diverse immune cell populations in human PHE tissue at a single-cell level. Our study identified 12 microglia subsets and 5 neutrophil subsets in human PHE tissue. What's more, we discovered that the secreted phosphoprotein-1 (SPP1) pathway served as the basis for self-communication between microglia subclusters during the progression of PHE. Additionally, we traced the trajectory branches of different neutrophil subtypes. Finally, we also demonstrated that microglia-produced osteopontin (OPN) could regulate the immune environment in PHE tissue by interacting with CD44-positive cells., Conclusions: As a result of our research, we have gained valuable insight into the immune-microenvironment within PHE tissue, which could potentially be used to develop novel treatment modalities for ICH., (© 2024. The Author(s).)

Objective: Intracerebral hemorrhage (ICH), the second most common type of stroke, can cause long-lasting disability in the afflicted patients. The study was conducted to examine the patterns of change in endogenous neural stem cells (eNSCs) and in the regenerative microenvironment after ICH, to observe the relationship between the migration of eNSCs and the pattern of change in the polarization state of immune cells in the microenvironment, and provide a research basis for research on clinical nerve repair., Methods: The collagenase injection method was used for modeling. The ICH model was induced in adult female Sprague-Dawley (SD) rats by injecting type VII collagenase (2 U) into the brain tissue of rats. All the experimental rats weighed 280-300 g. In order to simulate the ICU at different time points, including the acute phase (within 1 week), subacute phase (1-3 weeks), and the chronic phase (over 3 weeks), brain tissues were harvested at 3 day post injection (3 DPI), 10 DPI, 20 DPI, and 30 DPI to evaluate the modeling effect. Immunofluorescence staining of the brain tissue sections was performed with DCX antibody to observe the pattern of change in the migration of eNSCs in the brain tissue at different time points. Immunofluorescence staining of brain tissue sections was performed with CD206 antibody and CD86 antibody for respective observation of the pattern of change in pro-inflammatory (M1-type) and anti-inflammatory (M2-type) immune cells in the regenerative microenvironment of the brain tissue after ICM., Results: Spontaneous ICH was successfully induced by injecting type Ⅶ collagenase into the brain tissue of SD rats. The volume of the hematoma formed started to gradually increase at 3 DPI and reached its maximum at 10 DPI. After that, the hematoma was gradually absorbed and was completely absorbed by 30 DPI. Analysis of the pattern of changes in eNSCs in the brain tissue showed that a small number of eNSCs were activated at 3 DPI, but very soon their number started to decrease. By 10 DPI, eNSCs gradually began to increase. A large number of eNSCs migrated to the hemorrhage site at 20 DPI. Then the number of eNSCs decreased significantly at 30 DPI ( P <0.01). Analysis of the immune microenvironment of the brain tissue showed that pro-inflammatory (M1 type) immune cells increased significantly at 10 and 20 DPI ( P <0.01) and decreased at 30 DPI. Anti-inflammatory (M2 type) immune cells began to increase gradually at 3 DPI, decreased significantly at 20 DPI ( P <0.05), and then showed an increase at 30 DPI., Conclusion: After ICH in rats, eNSCs migrating toward the site of ICH first increase and then decrease. The immune microenvironment demonstrates a pattern of change in which inflammation is suppressed at first, then promoted, and finally suppressed again. Inflammation may have a stimulatory effect on the migration of eNSCs, but excessive inflammatory activation has an inhibitory effect on the differentiation and further activation of eNSCs. After ICH, the early stage of repair and protection (10 d) and the subacute phase (20 d) may provide the best opportunities for intervention., Competing Interests: 利益冲突　所有作者均声明不存在利益冲突, (© 2024《四川大学学报（医学版）》编辑部 版权所有Copyright ©2024 Editorial Office of Journal of Sichuan University (Medical Sciences).)

The evidence supports a strong link between immune cells and intracerebral hemorrhage (ICH). Nonetheless, the specific cause-and-effect associations between immune cells and ICH remain indeterminate. Here, our primary investigation compared immune cell infiltration in the ICH and sham groups using the GSE24265 dataset. Afterward, we extensively examined the relationship between immune cells and ICH by applying a two-sample Mendelian randomization (MR) analysis to identify the particular immune cells that may be associated with the initiation and advancement of ICH. Nevertheless, the specific processes that regulate the cause-and-effect connection between immune cells and ICH remain unknown. In this study, our objective was to investigate the connections between immune cell characteristics and plasma metabolites, as well as the links between plasma components and ICH. Our investigation uncovered that the levels of hypotaurine play a key role in the advancement of ICH, influencing the ratio of switched memory B cells among lymphocytes. Thus, our findings provide novel insights into the potential biological mechanisms underlying immune cell-mediated ICH., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Thrombocytopenia, anasarca, fever, renal dysfunction, and organomegaly (TAFRO) syndrome is an inflammatory disorder with an unclear pathogenesis. We herein report a case of TAFRO syndrome in remission in a patient who experienced recurrent intracranial bleeding despite a normal platelet count and coagulation system. A further investigation suggested the presence of anti-glycoprotein VI (GPVI) autoantibodies in the plasma, which induced platelet dysfunction and bleeding tendency. No new bleeding or relapse of TAFRO syndrome occurred after immunosuppressive therapy was initiated. These findings may help elucidate the autoimmune pathogenesis of TAFRO syndrome.

Background: Intracerebral hemorrhage (ICH) is a serious medical problem, and promising strategy is limited. Macrophage initiated brain inflammatory injury following ICH, but the molecular mechanism had not been well identified. E3 ligase Nedd4L is implicated in the pathogenesis of the inflammatory immune response., Methods: In the present study, we detected the levels of Nedd4L in macrophages following ICH. Furthermore, Macrophage M1 polarization, pro-inflammatory cytokine production, BBB disruption, brain water content and neurological function were examined in ICH mice., Results: Here, we demonstrated that E3 ligase Nedd4L levels of macrophage increased following ICH, promoted M1 polarization inflammation by TRAF3. Nedd4L promoted BBB disruption, as well as neurological deficits. Inhibition of Nedd4L significantly attenuated M1 polarization in vivo. Inhibition of Nedd4L decreased TRAF3 and TBK1 levels, and subsequent phosphorylation of p38 and NF-κB p65 subunit following ICH., Conclusions: Our data demonstrated that Nedd4L was involved in the pathogenesis of ICH, which promoted inflammatory responses and exacerbated brain damage by TRAF3 following ICH., Competing Interests: Declaration of Competing Interest None of the authors has any conflicts of interests, and agree to submit the manuscript., (Copyright © 2023. Published by Elsevier B.V.)

Background: Cerebral microbleeds (CMBs) are associated with a high risk for stroke . The present study determined whether long-term exposure to PM2.5 results in progressive worsening of CMBs and induction of systemic inflammation and microvascular oxidative stress., Methods: Sixteen male Spontaneously hypertensive rats (SHR) and eight Wistar-Kyoto (WKY) rats were exposed to either filtered air or PM2.5 for 12 months. To detect CMBs, rats were imaged using a 7-T MRI. To determine systemic inflammation and oxidative stress, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), as well as reactive oxygen species (ROS), NADPH activity and its subunits p22/47/67phox & gp91phox were measured., Results: During the exposure period, the mean daily concentration of PM2.5 was 59.2 ± 1.0 μg/m 3 . PM2.5 exposure significantly increased the incidence of CMBs compared to the PM2.5 (-) group (37.5% vs 12.5% incidence rate, p < 0.001). Animals exposed to PM2.5 also had significantly increased systolic blood pressures (SBPs) at 3 months (173 ± 5 vs 157 ± 5 mmHg, p < 0.05), 6 months (218 ± 6 vs 193 ± 7 mmHg, p < 0.01), 9 months (222 ± 6 vs 203 ± 8 mmHg, p < 0.05), and 12 months (231 ± 4 vs 207 ± 5 mmHg, p = 0.01). Additionally, there were significant elevations in IL-6, MCP-1, and TNF-α in the exposed group. Furthermore, PM2.5 significantly increased NOX activity and protein levels of gp91phox and p22/47/67phox., Conclusion: In the SHR model, long-term exposure to PM2.5 worsened CMBs, increased SBPs, induced systemic inflammation and oxidative stress. Therefore, PM2.5 is potentially a controllable risk factor that promotes CMBs in certain patients, such as those with hypertension.

Aged microglia display augmented inflammatory activity after neural injury. Although aging is a risk factor for poor outcome after brain insults, the precise impact of aging-related alterations in microglia on neural injury remains poorly understood. Microglia can be eliminated via pharmacological inhibition of the colony-stimulating factor 1 receptor (CSF1R). Upon withdrawal of CSF1R inhibitors, microglia rapidly repopulate the entire brain, leading to replacement of the microglial compartment. In this study, we investigated the impact of microglial replacement in the aged brain on neural injury using a mouse model of intracerebral hemorrhage (ICH) induced by collagenase injection. We found that replacement of microglia in the aged brain reduced neurological deficits and brain edema after ICH. Microglial replacement-induced attenuation of ICH injury was accompanied with alleviated blood-brain barrier disruption and leukocyte infiltration. Notably, newly repopulated microglia had reduced expression of IL-1β, TNF-α and CD86, and upregulation of CD206 in response to ICH. Our findings suggest that replacement of microglia in the aged brain restricts neuroinflammation and brain injury following ICH., (© 2021. The Author(s).)