Role and mechanisms of cytokines in the secondary brain injury after intracerebral hemorrhage

AX-024 Inhibits Antigen-Specific T-Cell Response and Improves Intracerebral Hemorrhage Outcomes in Mice

BACKGROUND

Stroke-induced opposite T-cell responses in the peri-lesion area and periphery worsen stroke outcomes by aggravating brain injury or increasing infectious complications, respectively. Despite their well-known role in T lymphocyte activation, the impact of TCRs (T-cell receptors) on stroke remains poorly understood. In this study, we investigated the causal link between TCRs and the opposite T-cell responses observed in intracerebral hemorrhage (ICH).

METHODS

We established the ICH model by injecting the collagenase VII-S into the left striatum of young adult (10-12 weeks) male and female and aged (18-20 months) male C57BL/6 mice. We intraperitoneally administered AX-024, a small molecule inhibitor of TCR signaling, and evaluated the results using flow cytometry, Western blotting, immunofluorescence staining, histological staining, bacterial culture, and behavioral tests.

RESULTS

Our findings in young adult male mice indicate that administering AX-024 within 48 hours suppressed the activation of nonspecific and antigen-specific CD3 (cluster of differentiation 3)+CD4+ and CD3+CD8+ cells in the brain 36 hours and 3 days after ICH but not 7 days after. Additionally, it temporarily inhibited antigen-specific T-cell activation in the periphery at the above 2 time points. It also reduced molecular and cellular neuroinflammation in the hemorrhagic brain early after ICH. These effects in the brain and periphery of young adult male mice ultimately improved ICH outcomes while having no impact on lung bacterial loads. This can be further supported by similar findings in young adult female and aged male mice with ICH.

CONCLUSIONS

AX-024 may represent a promising option for mitigating the detrimental effects of T cells entering the damaged brain without increasing bacterial loads in the lung in ICH. The potential of AX-024 as a potent immunosuppressive treatment for ICH is an exciting prospect that warrants further investigation.

Neutrophil-to-lymphocyte ratio as a predictor of prognosis in patients with spontaneous intracerebral hemorrhage: a systematic review and meta-analysis

Objective

To evaluate the predictive value of the neutrophil-to-lymphocyte ratio (NLR) for prognosis spontaneous intracerebral hemorrhage (ICH) patients.

Methods

PubMed, EMBASE, Cochrane Library, Web of Science were used for screening literature on NLR predicting ICH prognosis from database up to January 2024. Case-control or cohort studies that provided statistical analysis data on NLR predicting ICH prognosis were included. Data were combined using odds ratio (OR) and standard mean differences (SMD) for categorical variables and continuous variables, respectively. Meta-analysis, subgroup analyses, and sensitivity analyses were performed by Review Manager 5.4 and Stata 15.0.

Results

Meta-analysis of 21 studies with a total of 7,176 patients confirmed that NLR has a significant predictive value for mortality (SMD: 0.80, 95% CI: 0.58-1.02; OR: 1.10, 95% CI: 1.04-1.17) and neurological function outcomes (SMD: 0.66, 95% CI: 0.50-0.81; OR: 1.29, 95% CI: 1.17-1.41). NLR also significantly predicted the occurrence of stroke-associated pneumonia (SAP) (SMD: 0.54, 95% CI: 0.21-0.87). Subgroup analysis suggested that NLR had good predictive value for mortality in ICH patients aged ≥60 years, with hematoma volume > 15 mL, and NLR cut-off >7.5, and for neurological function in ICH patients, Asian patients, and those with NLR cut-off >7.5. The stability of the results was confirmed by sensitivity analysis.

Conclusion

NLR can significantly predict mortality, neurological function outcomes, and SAP occurrence in ICH patients. NLR cut-off >7.5 has good predictive value for both mortality and neurological function in ICH patients. Considering the limitations of this study, such as small sample size and potential heterogeneity, prospective studies with larger sample sizes are needed to confirm the findings of this article.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42024544506.

The Triad of Blood-Brain Barrier Integrity: Endothelial Cells, Astrocytes, and Pericytes in Perinatal Stroke Pathophysiology

Pediatric stroke, a significant cause of long-term neurological deficits in children, often arises from disruptions within neurovascular unit (NVU) components. The NVU, a dynamic ensemble of astrocytes, endothelial cells, pericytes, and microglia, is vital for maintaining cerebral homeostasis and regulating vascular brain development. Its structural integrity, particularly at the blood-brain barrier (BBB), depends on intercellular junctions and the basement membrane, which together restrict paracellular transport and shield the brain from systemic insults. Dysfunction in this intricate system is increasingly linked to pediatric stroke and related cerebrovascular conditions. Mutations disrupting endothelial cell adhesion or pericyte-endothelial interactions can compromise BBB stability, leading to pathological outcomes such as intraventricular hemorrhage in the germinal matrix, a hallmark of vascular brain immaturity. Additionally, inflammation, ferroptosis, necroptosis, and autophagy are key cellular processes influencing brain damage and repair. Excessive activation of these mechanisms can exacerbate NVU injury, whereas targeted therapeutic modulation offers potential pathways to mitigate damage and support recovery. This review explores the cellular and molecular mechanisms underlying NVU dysfunction, BBB disruption, and subsequent brain injury in pediatric stroke. Understanding the interplay between genetic mutations, environmental stressors, and NVU dynamics provides new insights into stroke pathogenesis. The susceptibility of the germinal matrix to vascular rupture further emphasizes the critical role of NVU integrity in early brain development. Targeting inflammatory pathways and cell death mechanisms presents promising strategies to preserve NVU function and improve outcomes for affected neonates.

From Molecular to Clinical Implications of Sleep-Related Breathing Disorders on the Treatment and Recovery of Acute Stroke: A Scoping Review

(1) Background: The aim of this review is to map research into the molecular mechanisms linking sleep-related breathing disorders (SRBDs) and acute stroke and their clinical and therapeutic implications and to identify existing knowledge gaps to suggest new areas of research. (2) Methods: This review was conducted according to the PRISMA extension for scoping reviews (PRISMA-ScR) and a predetermined protocol shared among all authors. (3) Results: The review of the thirteen studies analyzed provides a focused view of the molecular features about interaction between obstructive sleep apnea (OSA) and acute stroke. Our review identifies and highlights the biomarkers most frequently found to be associated with acute stroke, SRBDs, and their clinical repercussions. (4) Conclusions: The association between the presence of sleep apnea, especially in its severe form, and elevated levels of inflammatory markers in patients with acute stroke is highlighted and new research topics in this area are proposed.

Delivery of Tempol from Polyurethane Nanocapsules to Address Oxidative Stress Post-Injury

Traumatic brain injuries (TBIs) result in significant morbidity and mortality due to the cascade of secondary injuries involving oxidative stress and neuroinflammation. The development of effective therapeutic strategies to mitigate these effects is critical. This study explores the fabrication and characterization of polyurethane nanocapsules for the sustained delivery of Tempol, a potent antioxidant. The nanocapsules were designed to extend the release of Tempol over a 30-day period, addressing the prolonged oxidative stress observed post-TBI. Tempol-loaded polyurethane nanocapsules were synthesized using interfacial polymerization and nanoemulsion techniques. Two generations of nanocapsules were produced, differing in Tempol loading and PEGylation levels. The first generation, with lower Tempol loading, exhibited an average size of 159.8 ± 12.61 nm and a Z-average diameter of 771.9 ± 87.95 nm. The second generation, with higher Tempol loading, showed an average size of 141.4 ± 6.13 nm and a Z-average diameter of 560.7 ± 171.1 nm. The zeta potentials were -18.9 ± 5.02 mV and -11.9 ± 3.54 mV for the first and second generations, respectively. Both generations demonstrated the presence of urethane linkages, confirmed by Fourier Transform Infrared Spectroscopy (FTIR). Loading studies revealed Tempol concentrations of 61.94 ± 3.04 μg/mg for the first generation and 77.61 ± 3.04 μg/mg for the second generation nanocapsules. Release profiles indicated an initial burst followed by a sustained, nearly linear release over 30 days. The higher PEGylation in the second generation nanocapsules is advantageous for intravenous administration, potentially enhancing their therapeutic efficacy in TBI treatment. This study demonstrates the feasibility of using polyurethane nanocapsules for the prolonged delivery of Tempol, offering a promising approach to manage oxidative stress and improve outcomes in TBI patients. Future work will include testing these nanocapsules in vivo to determine their potential at modulating recovery from TBI.

Neuroinflammation and iron metabolism after intracerebral hemorrhage: a glial cell perspective

Intracerebral hemorrhage (ICH) is the most common subtype of hemorrhagic stroke causing significant morbidity and mortality. Previously clinical treatments for ICH have largely been based on a single pathophysiological perspective, and there remains a lack of curative interventions. Following the rupture of cerebral blood vessels, blood metabolites activate resident immune cells such as microglia and astrocytes, and infiltrate peripheral immune cells, leading to the release of a series of inflammatory mediators. Degradation of hemoglobin produces large amounts of iron ions, leading to an imbalance of iron homeostasis and the production of large quantities of harmful hydroxyl radicals. Neuroinflammation and dysregulation of brain iron metabolism are both important pathophysiological changes in ICH, and both can exacerbate secondary brain injury. There is an inseparable relationship between brain iron metabolism disorder and activated glial cells after ICH. Glial cells participate in brain iron metabolism through various mechanisms; meanwhile, iron accumulation exacerbates neuroinflammation by activating inflammatory signaling pathways modulating the functions of inflammatory cells, and so on. This review aims to explore neuroinflammation from the perspective of iron metabolism, linking the complex pathophysiological changes, delving into the exploration of treatment approaches for ICH, and offering insights that could enhance clinical management strategies.

Inhibition of tumor necrosis factor receptor-associated factor 6 alleviates secondary brain injury by reducing neuronal pyroptosis after intracerebral hemorrhage

Secondary brain injury (SBI) is one of the main causes of high mortality and disability rates following intracerebral hemorrhage (ICH). Tumor necrosis factor receptor-associated factor 6 (TRAF6) plays a crucial role in the process of pyroptosis, and modulating its expression may present a novel therapeutic strategy for mitigating brain injury. This study aims to explore the mechanisms of TRAF6 in pyroptosis after ICH. C57BL/6J mice were used to establish the ICH model. Brain was collected at different time points for q-PCR and western blot to detect the level of TRAF6. After the C25-140 (the TRAF6 inhibitor) was administrated, the mice were divided into four groups. Then, the neurological deficit, brain water content, and blood-brain barrier (BBB) damage were detected. Immunofluorescence and western blot were used to detect the level of pyroptosis proteins, and ELISA and q-PCR were used to detect the levels of IL-18 and IL-1β. TRAF6 expression was upregulated after ICH and was mainly expressed in neurons. Inhibition of TRAF6 expression with C25-140 alleviated neurological deficits and reduced brain edema after ICH. In addition, inhibition of TRAF6 also reduced the expression of pyroptosis inflammasomes such as GSDMD, NLRP3, and ASC, as well as neurological damage caused by IL-18 and IL-1β after ICH. TRAF6 regulates neuronal pyroptosis in SBI after ICH. Inhibition of TRAF6 may be a potential target for alleviating inflammatory damage after ICH.

Immune Cells and Intracerebral Hemorrhage: A Causal Investigation Through Mendelian Randomization

BACKGROUND

The involvement of immune cells in the pathophysiology of intracerebral hemorrhage (ICH) is becoming increasingly recognized, yet their specific causal contributions remain uncertain. The objective of this research is to uncover the potential causal interactions between diverse immune cells and ICH using Mendelian randomization (MR) analysis.

METHODS

Genetic variants associated with 731 immune cell traits were sourced from a comprehensive genome-wide association study (GWAS) involving 3757 participants. Summary statistics data for ICH were acquired from FinnGen, comprising 4056 ICH cases and 371,717 controls. The principal analytical tool utilized in our study was the inverse-variance weighted (IVW) method, incorporated as a key component of a two-sample MR approach. To mitigate potential biases and verify the stability of the conclusions drawn from the primary analytical methods, a series of sensitivity analyses were performed.

RESULTS

MR analysis elucidated 33 immune cell traits with causal associations, comprising B cells (eight traits), conventional dendritic cells (cDC, two traits), maturation stages of T cells (two traits), monocytes (two traits), myeloid cells (five traits), TBNK cells (six traits), and regulatory T cells (Treg, eight traits). DP (CD4+CD8+) %T cell (OR = 0.83, CI = 0.72-0.96, p = 0.013) exhibited the strongest protective effect. In contrast, transitional AC (OR = 1.09, CI = 1.02-1.16, p = 0.006) and IgD- CD27- %lymphocyte (OR = 1.08, CI = 1.00-1.17, p = 0.045) showed a higher tendency to increase the ICH risk. The sensitivity analyses validated the robustness and consistency of these results.

CONCLUSION

Our research provides robust evidence substantiating the causal relationship between specific immunophenotypes and ICH risk. The identification of these findings significantly enhances our understanding of the pathogenic mechanisms underlying ICH, particularly pertaining to the immune system. This breakthrough paves the way for innovative clinical and pharmaceutical research opportunities, potentially promoting the development of targeted therapies and enhanced strategies for managing and preventing ICH.

Promotive effect of skin precursor-derived Schwann cells on brachial plexus neurotomy and motor neuron damage repair through milieu-regulating secretome

Brachial plexus injury (BPI) with motor neurons (MNs) damage still remain poor recovery in preclinical research and clinical therapy, while cell-based therapy approaches emerged as novel strategies. Previous work of rat skin precursor-derived Schwann cells (SKP-SCs) provided substantial foundation for repairing peripheral nerve injury (PNI). Given that, our present work focused on exploring the repair efficacy and possible mechanisms of SKP-SCs implantation on rat BPI combined with neurorrhaphy post-neurotomy. Results indicated the significant locomotive and sensory function recovery, with improved morphological remodeling of regenerated nerves and angiogenesis, as well as amelioration of target muscles atrophy and motor endplate degeneration. Besides, MNs could restore from oxygen-glucose-deprivation (OGD) injury upon SKP-SCs-sourced secretome treatment, implying the underlying paracrine mechanisms. Moreover, rat cytokine array assay detected 67 cytokines from SKP-SC-secretome, and bioinformatic analyses of screened 32 cytokines presented multiple functional clusters covering diverse cell types, including inflammatory cells, Schwann cells, vascular endothelial cells (VECs), neurons, and SKP-SCs themselves, relating distinct biological processes to nerve regeneration. Especially, a panel of hypoxia-responsive cytokines (HRCK), can participate into multicellular biological process regulation for permissive regeneration milieu, which underscored the benefits of SKP-SCs and sourced secretome, facilitating the chorus of nerve regenerative microenvironment. Furthermore, platelet-derived growth factor-AA (PDGF-AA) and vascular endothelial growth factor-A (VEGF-A) were outstanding cytokines involved with nerve regenerative microenvironment regulating, with significantly elevated mRNA expression level in hypoxia-responsive SKP-SCs. Altogether, through recapitulating the implanted SKP-SCs and derived secretome as niche sensor and paracrine transmitters respectively, HRCK would be further excavated as molecular underpinning of the neural recuperative mechanizations for efficient cell therapy; meanwhile, the analysis paradigm in this study validated and anticipated the actions and mechanisms of SKP-SCs on traumatic BPI repair, and was beneficial to identify promising bioactive molecule cocktail and signaling targets for cell-free therapy strategy on neural repair and regeneration.

Microglial mitochondrial DNA release contributes to neuroinflammation after intracerebral hemorrhage through activating AIM2 inflammasome

Intracerebral hemorrhage (ICH) is a severe disease that often leads to disability and death. Neuroinflammatory response is a key causative factor of early secondary brain injury after ICH. AIM2 is a DNA-sensing protein that recognizes cytosolic double-stranded DNA and take a significant part in neuroinflammation. Mitochondrial DNA participates in the translation of proteins such as the respiratory chain in the mitochondria. Whether mtDNA is involved in forming AIM2 inflammasome after ICH remains unclear. We used mice to construct ICH model in vivo and we used BV2 microglial cells treated with oxyhemoglobin to simulate ICH in vitro. Following lentiviral transfection to overexpress AIM2 antagonist P202, a notable decrease was observed in the levels of AIM2 inflammasome-associated proteins, leading to a reduction in dead neurons surrounding the hematoma and an enhancement in long-term and short-term behavior of neurological deficits. We further explored whether mtDNA took part in the AIM2 activation after ICH. The cytosolic mtDNA level was down-regulated by the mitochondrial division protector Mdivi-1 and up-regulated by transfection of mtDNA into cytoplasm. We found the expression level of AIM2 inflammasome-related proteins and inflammatory cytokines release were regulated by the cytosolic mtDNA level. In conclusion, after ICH, the mtDNA content in the cytoplasm of microglia around the hematoma rises, causing AIM2 inflammation leading to neuronal apoptosis, which leads to neurological deficits in mice. On the other hand, P202 was able to block inflammatory vesicle activation and improve neurological function by preventing the interaction between AIM2 protein and mitochondrial DNA.

Gut microbiota dysbiosis and neurological function recovery after intracerebral hemorrhage: an analysis of clinical samples

We aimed to investigate the microbial community composition in patients with intracerebral hemorrhage (ICH) and its effect on prognosis. We designed two clinical cohort studies to explore the gut dysbiosis after ICH and their relationship with neurological function prognosis. First, fecal samples from patients with ICH at three time points: T1 (within 24 h of admission), T2 (3 days after surgery), and T3 (7 days after surgery), and healthy volunteers were subjected to 16S rRNA sequencing using Illumina high-throughput sequencing technology. When differential gut microbiota was identified, the correlation between clinical indicators and microbiotas was analyzed. Subsequently, the patients with ICH were categorized into GOOD and POOR groups based on their Glasgow Outcome Scale Extended (GOS-E) score, and the disparities in gut microbiota between the two groups were assessed. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors. The composition and diversity of the gut microbiota in patients with ICH were different from those in the control group and changed dynamically with the extension of the course of cerebral hemorrhage. The abundances of Enterococcaceae, Clostridiales incertae sedis XI, and Peptoniphilaceae were significantly increased in patients with ICH, whereas Bacteroidaceae, Ruminococcaceae, Lachnospiraceae, and Veillonellaceae were significantly reduced. The relative abundance of Enterococcus gradually increased with the extension of the duration of ICH after surgery, and the abundance of Bacteroides gradually decreased. The abundance of Enterococcus before surgery was found to be negatively associated with patient neurological function prognosis. The original ICH score and Lachnospiraceae status were independent risk factors for predicting the prognosis of neurological function in patients with ICH (P < 0.05). Changes in the gut microbiota diversity in patients with ICH were related to prognosis. Lachnospiraceae may have a protective effect on prognosis.IMPORTANCEAcute central nervous system injuries like hemorrhagic stroke are major global health issues. While surgical hematoma removal can alleviate brain damage, severe cases still have a high 1-month mortality rate of up to 40%. Gut microbiota significantly impacts health, and treatments like fecal microbiota transplantation (FMT) and probiotics can improve brain damage by correcting gut microbiota imbalances caused by ischemic stroke. However, few clinical studies have explored this relationship in hemorrhagic stroke. This study investigated the impact of cerebral hemorrhage on the composition of gut microbiota, and we found that Lachnospiraceae were the independent risk factors for poor prognosis in intracerebral hemorrhage (ICH). The findings offer potential insights for the application of FMT in patients with ICH, and it may improve the prognosis of patients.

Cystatin C Attenuates Perihematomal Secondary Brain Injury by Inhibiting the Cathepsin B/NLRP3 Signaling Pathway in a Rat Model of Intracerebral Hemorrhage

Secondary brain injury (SBI) is a noticeable contributor to the high mortality and morbidity rates associated with intracerebral hemorrhage (ICH), and effective treatment options remain limited. Cystatin C (CysC) emerges as a novel candidate for SBI intervention. The therapeutic effects and underlying mechanisms of CysC in mitigating SBI following ICH were explored in the current research. An in vivo ICH rat model was established by injecting autologous blood into the right caudate nucleus. Western blotting (WB) was utilized to assess the levels of CysC, cathepsin B (CTSB), and the NLRP3 inflammasome. Subsequently, the ICH rat model was treated with exogenous CysC supplementation or CysC knockdown plasmids. Various parameters, including Evans blue (EB) extravasation, brain water content, and neurological function in rats, were examined. RT-qPCR and WB were employed to determine the expression levels of CTSB and the NLRP3 inflammasome. The co-expression of CTSB, CysC, and NLRP3 inflammasome with GFAP, NeuN, and Iba1 was assessed through double-labeled immunofluorescence. The interaction between CysC and CTSB was investigated using double-labeled immunofluorescence and co-immunoprecipitation. The findings revealed an elevation of CysC expression level, particularly at 24 h after ICH. Exogenous CysC supplementation alleviated severe brain edema, neurological deficit scores, and EB extravasation induced by ICH. Conversely, CysC knockdown produced opposite effects. The expression levels of CTSB and the NLRP3 inflammasome were significantly risen following ICH, and exogenous CysC supplement attenuated their expression levels. Double-labeled immunofluorescence illustrated that CysC, CTSB, and the NLRP3 inflammasome were predominantly expressed in microglial cells, and the interaction between CysC and CTSB was evidenced. CysC exhibited potential in ameliorating SBI following ICH via effectively suppressing the activation of the NLRP3 inflammasome mediated by CTSB specifically in microglial cells. These findings underscore the prospective therapeutic efficacy of CysC in the treatment of ICH-induced complications.

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.

Therapeutic approaches to microglial dysfunction in Alzheimer's disease: Enhancing phagocytosis and metabolic regulation

Microglia are essential in neurogenesis, synaptic pruning, and homeostasis. Nevertheless, aging, and cellular senescence may modify their role, causing them to shift from being shields to being players of neurodegeneration. In the aging brain, the population of microglia increases, followed by enhanced activity of genes related to neuroinflammation. This change increases their ability to cause inflammation, resulting in a long-lasting state of inflammation in the brain that harms the condition of neurons. In Alzheimer's Disease (AD), microglia are located inside amyloid plaques and exhibit an inflammatory phenotype characterized by a diminished ability to engulf and remove waste material, worsening the illness's advancement. Genetic polymorphisms in TREM2, APOE, and CD33 highlight the significant impact of microglial dysfunction in AD. This review examines therapeutic approaches that aim to address microglial dysfunction, such as enhancing the microglial capability to engulf and remove amyloid-β clumps and regulating microglial metabolism and mitochondrial activity. Microglial transplanting and reprogramming advancements show the potential to restore their ability to reduce inflammation. Although there has been notable advancement, there are still voids in our knowledge of microglial biology, including their relationships with other brain cells. Further studies should prioritize the improvement of human AD models, establish standardized methods for characterizing microglia, and explore how various factors influence microglial responses. It is essential to tackle these problems to create effective treatment plans that focus on reducing inflammation in the brain and protecting against damage in age-related neurodegenerative illnesses.

Unraveling the protein post-translational modification landscape: Neuroinflammation and neuronal death after stroke

The impact of stroke on global health is profound, with both high mortality and morbidity rates. This condition can result from cerebral ischemia, intracerebral hemorrhage (ICH), and subarachnoid hemorrhage (SAH). The pathophysiology of stroke involves secondary damage and irreversible loss of neuronal function. Post-translational modifications (PTMs) have been recognized as crucial regulatory mechanisms in ischemic and hemorrhagic stroke-induced brain injury. These PTMs include phosphorylation, glycosylation, ubiquitination, SUMOylation, acetylation, and succinylation. This comprehensive review delves into recent research on the PTMs landscape associated with neuroinflammation and neuronal death specific to cerebral ischemia, ICH, and SAH. This review aims to explain the role of PTMs in regulating pathologic mechanisms and present critical techniques and proteomic strategies for identifying PTMs. This knowledge helps us comprehend the underlying mechanisms of stroke injury and repair processes, leading to the development of innovative treatment strategies. Importantly, this review underscores the significance of exploring PTMs to understand the pathophysiology of stroke.

The Role of Complement C1qa in Experimental Intracerebral Hemorrhage

Evidence indicates that the complement system is activated and plays a role in brain injury after intracerebral hemorrhage (ICH). Most studies have focused on the role of C3, C5 and the membrane attack complex. The purpose of this study was to investigate the potential impact of complement C1q, a key upstream component of the classical pathway, on ICH-induced brain injury. Wild-type (WT) and C1qa knock out (KO) mice were compared using an autologous blood injection ICH model. Magnetic resonance imaging (MRI) was performed on days 1, 3 and 7 and brains harvested on days 3 and 7 for immunohistochemistry to examine brain injury mechanisms. WT and C1qa KO mice also received an intracerebral injection of thrombin, a key factor in ICH-induced brain injury. Following MRI scans, brains were harvested for immunohistochemistry on day 1. In comparison to WT mice, C1qa KO mice had reduced hematoma erythrolysis and neutrophil infiltration after ICH. However, they also had delayed hematoma clearance, which was associated with reduced induction of phagocytic multinuclear giant cells, and increased perihematomal neuronal damage. After thrombin injection, C1qa KO mice had smaller lesion volumes, less neuronal loss, reduced neutrophil infiltration, and less BBB damage. C1qa knockout has beneficial and detrimental effects on ICH-induced brain injury mechanisms, but a consistent beneficial effect after thrombin injection. Strategies to balance the roles of C1q after ICH may represent a promising therapeutic direction.

Exploring the correlation between innate immune activation of inflammasome and regulation of pyroptosis after intracerebral hemorrhage: From mechanism to treatment

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.

Edaravone Maintains AQP4 Polarity Via OS/MMP9/β-DG Pathway in an Experimental Intracerebral Hemorrhage Mouse Model

Oxidative stress (OS) is the main cause of secondary damage following intracerebral hemorrhage (ICH). The polarity expression of aquaporin-4 (AQP4) has been shown to be important in maintaining the homeostasis of water transport and preventing post-injury brain edema in various neurological disorders. This study primarily aimed to investigate the effect of the oxygen free radical scavenger, edaravone, on AQP4 polarity expression in an ICH mouse model and determine whether it involves in AQP4 polarity expression via the OS/MMP9/β-dystroglycan (β-DG) pathway. The ICH mouse model was established by autologous blood injection into the basal nucleus. Edaravone or the specific inhibitor of matrix metalloproteinase 9 (MMP9), MMP9-IN-1, called MMP9-inh was administered 10 min after ICH via intraperitoneal injection. ELISA detection, neurobehavioral tests, dihydroethidium staining (DHE staining), intracisternal tracer infusion, hematoxylin and eosin (HE) staining, immunofluorescence staining, western blotting, Evans blue (EB) permeability assay, and brain water content test were performed. The results showed that OS was exacerbated, AQP4 polarity was lost, drainage function of brain fluids was damaged, brain injury was aggravated, expression of AQP4, MMP9, and GFAP increased, while the expression of β-DG decreased after ICH. Edaravone reduced OS, restored brain drainage function, reduced brain injury, and downregulated the expression of AQP4, MMP9. Both edaravone and MMP9-inh alleviated brain edema, maintained blood-brain barrier (BBB) integrity, mitigated the loss of AQP4 polarity, downregulated GFAP expression, and upregulated β-DG expression. The current study suggests that edaravone can maintain AQP4 polarity expression by inhibiting the OS /MMP9/β-DG pathway after ICH.

Central post-stroke pain: advances in clinical and preclinical research

Central poststroke pain (CPSP) is a medical complication that arises poststroke and significantly impacts the quality of life and social functioning of affected individuals. Despite ongoing research, the exact pathomechanisms of CPSP remain unclear, and practical treatments are still unavailable. Our review aims to systematically analyse current clinical and preclinical studies on CPSP, which is critical for identifying gaps in knowledge and guiding the development of effective therapies. The review will clarify the clinical characteristics, evaluation scales and contemporary therapeutic approaches for CPSP based on clinical investigations. It will particularly emphasise the CPSP model initiated by stroke, shedding light on its underlying mechanisms and evaluating treatments validated in preclinical studies. Furthermore, the review will not only highlight methodological limitations in animal trials but also offer specific recommendations to researchers to improve the quality of future investigations and guide the development of effective therapies. This review is expected to provide valuable insights into the current knowledge regarding CPSP and can serve as a guide for future research and clinical practice. The review will contribute to the scientific understanding of CPSP and help develop effective clinical interventions.

MicroRNA-195-5p Inhibits Intracerebral Hemorrhage-Induced Inflammatory Response and Neuron Cell Apoptosis

Intracerebral hemorrhage (ICH) is a severe condition characterized by bleeding within brain tissue. Primary brain injury in ICH results from a mechanical insult caused by blood accumulation, whereas secondary injury involves inflammation, oxidative stress, and disruption of brain physiology. miR-195-5p may participate in ICH pathology by regulating cell proliferation, oxidative stress, and inflammation. Therefore, we assessed the performance of miR-195-5p in alleviating ICH-induced secondary brain injury. ICH was established in male Sprague-Dawley rats (7 weeks old, 200-250 g) via the stereotaxic intrastriatal injection of type IV bacterial collagenase, after which miR-195-5p was administered intravenously. Neurological function was assessed using corner turn and forelimb grip strength tests. Protein expression was assessed by western blotting and ELISA. The miR-195-5p treatment significantly improved neurological function; modulated macrophage polarization by promoting anti-inflammatory marker (CD206 and Arg1) production and inhibiting pro-inflammatory marker (CD68 and iNOS) production; enhanced Akt signalling, reduced oxidative stress by increasing Sirt1 and Nrf2 levels, and attenuated inflammation by decreasing NF-κB activation; inhibited apoptosis via increased Bcl-2 and decreased cleaved caspase-3 levels; and regulated synaptic plasticity by modulating NMDAR2A, NMDAR2B, BDNF, and TrkB expression and ERK and CREB phosphorylation. In conclusion, miR-195-5p exerts neuroprotective effects in ICH by reducing inflammation and oxidative stress, inhibiting apoptosis, and restoring synaptic plasticity, ultimately restoring behavioral recovery, and represents a promising therapeutic agent that warrants clinical studies.

A comprehensive review of traditional Chinese medicine in treating neuropathic pain

Neuropathic pain (NP) is a common, intractable chronic pain caused by nerve dysfunction and primary lesion of the nervous system. The etiology and pathogenesis of NP have not yet been clarified, so there is a lack of precise and effective clinical treatments. In recent years, traditional Chinese medicine (TCM) has shown increasing advantages in alleviating NP. Our review aimed to define the therapeutic effect of TCM (including TCM prescriptions, TCM extracts and natural products from TCM) on NP and reveal the underlying mechanisms. Literature from 2018 to 2024 was collected from databases including Web of Science, PubMed, ScienceDirect, Google academic and CNKI databases. Herbal medicine, Traditional Chinese medicines (TCM), neuropathic pain, neuralgia and peripheral neuropathy were used as the search terms. The anti-NP activity of TCM is clarified to propose strategies for discovering active compounds against NP, and provide reference to screen anti-NP drugs from TCM. We concluded that TCM has the characteristics of multi-level, multi-component, multi-target and multi-pathway, which can alleviate NP through various pathways such as anti-inflammation, anti-oxidant, anti-apoptotic pathway, regulating autophagy, regulating intestinal flora, and influencing ion channels. Based on the experimental study and anti-NP mechanism of TCM, this paper can offer analytical evidence to support the effectiveness in treating NP. These references will be helpful to the research and development of innovative TCM with multiple levels and multiple targets. TCM can be an effective treatment for NP and can serve as a treasure house for new drug development.

Associations of serum Dickkopf-1 levels with disease severity and 90-day Prognosis after spontaneous intracerebral hemorrhage: results from the prospective cohort study

Dickkopf-1 (DKK-1) may be involved in inflammatory response and secondary brain injury after acute brain injury. We gauged serum DKK-1 levels and further assessed its correlation with disease severity and investigated its predictive value for 90-day prognosis in patients with spontaneous intracerebral hemorrhage (sICH). Serum DKK-1 levels were measured in 128 sICH patients and 128 healthy controls. The severity of sICH was assessed using the Glasgow Coma Scale (GCS) scores and hematoma volumes. Poor prognosis was referred to as a Glasgow Outcome Scale (GOS) score of 1-3 at 90 days after stroke. Multivariate analysis was performed to identify associations of serum DKK-1 levels with disease severity, early neurological deterioration (END) and poor prognosis. Receiver operating characteristic curve (ROC) was built to investigate the prognostic predictive capability. The serum DKK-1 levels of patients were significantly higher than those of controls (median, 4.74 ng/mL versus 1.98 ng/mL; P < 0.001), and were independently correlated with hematoma volumes (ρ = 0.567, P < 0.001; t = 3.444, P = 0.001) and GCS score (ρ = -0.612, P < 0.001; t = -2.048, P = 0.043). Serum DKK-1 significantly differentiated patients at risk of END (area under ROC curve (AUC), 0.850; 95% confidence interval (CI), 0.777-0.907; P < 0.001) and poor prognosis (AUC, 0.830; 95% CI, 0.753-0.890; P < 0.001), which had similar prognostic ability, as compared to GCS scores and hematoma volumes. Subsequent Logistic regression model affirmed that GCS score, hematoma volume, and serum DKK-1 levels were independently associated with END and poor prognosis at 90 days after sICH. The models, which contained them, performed well using ROC curve analysis and calibration curve analysis. Serum DKK-1 levels are markedly associated with disease severity, END and 90-day poor prognosis in sICH. Hence, serum DKK-1 is presumed to be used as a potential prognostic biomarker of sICH.

Veliparib exerts protective effects in intracerebral hemorrhage mice by inhibiting the inflammatory response and accelerating hematoma resolution

Poly (ADP-ribose) polymerase (PARP) inhibitors have potent anti-inflammatory effects, including the suppression of brain microglial activation. Veliparib, a well-known PARP1/2 inhibitor, exhibits particularly high brain penetration, but its effects on stroke outcome is unknown. Here, the effects of veliparib on the short-term outcome of intracerebral hemorrhage (ICH), the most lethal type of stroke, were investigated. Collagenase-induced mice ICH model was applied, and the T2-weighted magnetic resonance imaging was performed to evaluate lesion volume. Motor function and hematoma volume were also measured. We further performed immunofluorescence, enzyme linked immunosorbent assay, flow cytometry, and blood-brain barrier assessment to explore the potential mechanisms. Our results demonstrated veliparib reduced the ICH lesion volume dose-dependently and at a dosage of 5 mg/kg, veliparib significantly improved mouse motor function and promoted hematoma resolution at days 3 and 7 post-ICH. Veliparib inhibited glial activation and downregulated the production of pro-inflammatory cytokines. Veliparib significantly decreased microglia counts and inhibited peripheral immune cell infiltration into the brain on day 3 after ICH. Veliparib improved blood-brain barrier integrity at day 3 after ICH. These findings demonstrate that veliparib improves ICH outcome by inhibiting inflammatory responses and may represent a promising novel therapy for ICH.

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.

Role and mechanisms of mast cells in brain disorders

Mast cells serve as crucial effector cells within the innate immune system and are predominantly localized in the skin, airways, gastrointestinal tract, urinary and reproductive tracts, as well as in the brain. Under physiological conditions, brain-resident mast cells secrete a diverse array of neuro-regulatory mediators to actively participate in neuroprotection. Meanwhile, as the primary source of molecules causing brain inflammation, mast cells also function as the "first responders" in brain injury. They interact with neuroglial cells and neurons to facilitate the release of numerous inflammatory mediators, proteases, and reactive oxygen species. This process initiates and amplifies immune-inflammatory responses in the brain, thereby contributing to the regulation of neuroinflammation and blood-brain barrier permeability. This article provides a comprehensive overview of the potential mechanisms through which mast cells in the brain may modulate neuroprotection and their pathological implications in various neurological disorders. It is our contention that the inhibition of mast cell activation in brain disorders could represent a novel avenue for therapeutic breakthroughs.

GM130-silencing may aggravate blood-brain barrier damage and affect microglia polarization by down-regulating PD-L1 expression after experimental intracerebral hemorrhage

BACKGROUND

In addition to primary injury, secondary injuries related to BBB disruption and immune-inflammatory response also play an important role in intracerebral hemorrhage (ICH). And the Golgi apparatus play an important role in the state of ICH.

METHODS

ICH model and GM130-silencing ICH model were established in SD rats. The Garcia score was used to score the neurological defects of the rats. Blood-brain barrier (BBB) integrity were assessed by amount of extravasated Evans blue, and tight junction proteins. The expression of PD-L1 and GM130were detected through Western-blot and the subtype of microglia was showing with Immunofluorescence staining.

RESULTS

Compared with the ICH group, GM130-silencing ICH rats got a worsened neurological deficit and enlarged volume of the hematoma. Evan's blue extravasation aggravated as well. The expression of GM130 in peri-hematoma tissue was further decreased, and the morphology and structure of the Golgi apparatus were further damaged. Meanwhile, the GM130 deficit resulted in decreased expression of PD-L1 and more polarization of microglia to the M1 subtype.

CONCLUSION

We demonstrate that GM130 could influence the integrity of BBB and plays a role in neuroinflammation via regulation of PD-L1 after ICH. The manipulation of GM130 might be a promising therapeutical target in ICH.

Leonurus japonicus Houtt. modulates neuronal apoptosis in intracerebral hemorrhage: Insights from network pharmacology and molecular docking

ETHNOPHARMACOLOGICAL RELEVANCE

Leonurus japonicus Houtt. (Labiatae), commonly known as Chinese motherwort, is a herbaceous flowering plant that is native to Asia. It is widely acknowledged in traditional medicine for its diuretic, hypoglycemic, antiepileptic properties and neuroprotection. Currently, Leonurus japonicus (Leo) is included in the Pharmacopoeia of the People's Republic of China. Traditional Chinese Medicine (TCM) recognizes Leo for its myriad pharmacological attributes, but its efficacy against ICH-induced neuronal apoptosis is unclear.

AIMS OF THE STUDY

This study aimed to identify the potential targets and regulatory mechanisms of Leo in alleviating neuronal apoptosis after ICH.

MATERIALS AND METHODS

The study employed network pharmacology, UPLC-Q-TOF-MS technique, molecular docking, pharmacodynamic studies, western blotting, and immunofluorescence techniques to explore its potential mechanisms.

RESULTS

Leo was found to assist hematoma absorption, thus improving the neurological outlook in an ICH mouse model. Importantly, molecular docking highlighted JAK as Leo's potential therapeutic target in ICH scenarios. Further experimental evidence demonstrated that Leo adjusts JAK1 and STAT1 phosphorylation, curbing Bax while augmenting Bcl-2 expression.

CONCLUSION

Leo showcases potential in mitigating neuronal apoptosis post-ICH, predominantly via the JAK/STAT mechanism.

Silencing CXCL16 alleviate neuroinflammation and M1 microglial polarization in mouse brain hemorrhage model and BV2 cell model through PI3K/AKT pathway

Neuroinflammation and microglia polarization play pivotal roles in brain injury induced by intracerebral hemorrhage (ICH). Despite the well-established involvement of CXC motif chemokine ligand 16 (CXCL16) in regulating inflammatory responses across various diseases, its specific functions in the context of neuroinflammation and microglial polarization following ICH remain elusive. In this study, we investigated the impact of CXCL16 on neuroinflammation and microglia polarization using both mouse and cell models. Our findings revealed elevated CXCL16 expression in mice following ICH and in BV2 cells after lipopolysaccharide (LPS) stimulation. Specific silencing of CXCL16 using siRNA led to a reduction in the expression of neuroinflammatory factors, including IL-1β and IL-6, as well as decreased expression of the M1 microglia marker iNOS. Simultaneously, it enhanced the expression of anti-inflammatory factors such as IL-10 and the M2 microglia marker Arg-1. These results were consistent across both mouse and cell models. Intriguingly, co-administration of the PI3K-specific agonist 740 Y-P with siRNA in LPS-stimulated cells reversed the effects of siRNA. In conclusion, silencing CXCL16 can positively alleviate neuroinflammation and M1 microglial polarization in BV2 inflammation models and ICH mice. Furthermore, in BV2 cells, this beneficial effect is mediated through the PI3K/Akt pathway. Inhibition of CXCL16 could be a novel approach for treating and diagnosing cerebral hemorrhage.

Gut microbiota is necessary for pair-housing to protect against post-stroke depression in mice

The goal of this study is to investigate the role of microbiota-gut-brain axis involved in the protective effect of pair-housing on post-stroke depression (PSD). PSD model was induced by occluding the middle cerebral artery (MCAO) plus restraint stress for four weeks. At three days after MCAO, the mice were restrained 2 h per day. For pair-housing (PH), each mouse was pair housed with a healthy isosexual cohabitor for four weeks. While in the other PH group, their drinking water was replaced with antibiotic water. On day 35 to day 40, anxiety- and depression-like behaviors (sucrose consumption, open field test, forced swim test, and tail-suspension test) were conducted. Results showed pair-housed mice had better performance on anxiety- and depression-like behaviors than the PSD mice, and the richness and diversity of intestinal flora were also improved. However, drinking antibiotic water reversed the effects of pair-housing. Furthermore, pair-housing had an obvious improvement in gut barrier disorder and inflammation caused by PSD. Particularly, they showed significant decreases in CD8 lymphocytes and mRNA levels of pro-inflammatory cytokines (TNF-a, IL-1β and IL-6), while IL-10 mRNA was upregulated. In addition, pair-housing significantly reduced activated microglia and increased Nissl's body in the hippocampus of PSD mice. However, all these improvements were worse in the pair-housed mice administrated with antibiotic water. We conclude that pair-housing significantly improves PSD in association with enhanced functions of microbiota-gut-brain axis, and homeostasis of gut microbiota is indispensable for the protective effect of pair-housing on PSD.

The Role of Systemic Inflammation in the Pathogenesis of Spontaneous Intracranial Hemorrhage in the Presence or Absence of Effective Cerebral Blood Flow

Background: Spontaneous intracerebral hemorrhage (ICH) is one of the leading causes of mortality in intensive care units. The role of systemic hyperintense inflammation (SHI) in the pathogenesis of critical complications of ICH remains a poorly understood problem. There is a specific variant of severe ICH associated with increased intracranial pressure and occlusion of intracranial vessels, defined as ineffective cerebral blood flow (IECBF). Methods: To evaluate the role of SHI in the pathogenesis of severe (comatose) ICH in a dynamic comparison of patients with IECBF (n-26) and without IECBF (n-52). The SHI integral score criterion (SI scale) was used, including certain values of plasma concentrations of IL-6, IL-8, IL-10; TNF-α, PCT, cortisol, myoglobin, troponin I, D-dimer, and, additionally, SOFA scale values. Blood levels of ACTH and neuron-specific enolase (NSE) were also assessed. Results: Twenty-eight-day mortality in severe ICH reached 84.6% (without IECBF) and 96.2% (with IECBF). Clear signs of SHI were detected in 61.5%/87.8% (without IECBF) and 0.0%/8.7% (with IECBF) within 1-3/5-8 days from the onset of ICH manifestation. The lower probability of developing SHI in the IECBF group was associated with low blood NSE concentrations. Conclusions: The development of SHI in ICH is pathogenetically related to the permeability of the blood-brain barrier for tissue breakdown products and other neuroinflammatory factors.

Transcriptomic analysis reveals novel hub genes associated with astrocyte autophagy in intracerebral hemorrhage

Introduction

Neuroinflammation serves as a critical local defense mechanism against secondary brain injury following intracerebral hemorrhage (ICH), and astrocytes play a prominent role in this process. In this study, we investigated astrocytic changes during the inflammatory state after ICH to identify new targets for improving the inflammatory response.

Methods

We stimulated mouse astrocytes with lipopolysaccharide (LPS) in vitro and analyzed their transcriptomes via ribonucleic acid sequencing. We created an ICH model in living organisms by injecting autologous blood.

Results

RNA sequencing revealed that 2,717 genes were differentially expressed in the LPS group compared to those in the saline group, with notable enrichment of the autophagic pathway. By intersecting the 2,717 differentially expressed genes (DEGs) with autophagy-related genes, we identified 36 autophagy-related DEGs and seven hub genes. Previous studies and quantitative reverse transcription-polymerase chain reaction results confirmed the increased expression of phosphatidylinositol 3-kinase catalytic subunit type 3 (Pik3c3), AKT serine/threonine kinase 1 (Akt1), and unc-51 like autophagy activating kinase 2 (Ulk2) in astrocytes after ICH. Transcription factors and target miRNAs were identified for the final three DEGs, and 3-methyladenine and leupeptin were identified as potential therapeutic agents for ICH.

Conclusion

Our findings suggest that astrocyte autophagy plays a critical role in ICH complexity, and that Pik3c3, Akt1, and Ulk2 may be potential therapeutic targets.

Nanozymes: Potential Therapies for Reactive Oxygen Species Overproduction and Inflammation in Ischemic Stroke and Traumatic Brain Injury

Nanozymes, which can selectively scavenge reactive oxygen species (ROS), have recently emerged as promising candidates for treating ischemic stroke and traumatic brain injury (TBI) in preclinical models. ROS overproduction during the early phase of these diseases leads to oxidative brain damage, which has been a major cause of mortality worldwide. However, the clinical application of ROS-scavenging enzymes is limited by their short in vivo half-life and inability to cross the blood-brain barrier. Nanozymes, which mimic the catalytic function of natural enzymes, have several advantages, including cost-effectiveness, high stability, and easy storage. These advantages render them superior to natural enzymes for disease diagnosis and therapeutic interventions. This review highlights recent advancements in nanozyme applications for ischemic stroke and TBI, emphasizing their potential to mitigate the detrimental effect of ROS overproduction, oxidative brain damage, inflammation, and blood-brain barrier compromise. Therefore, nanozymes represent a promising treatment modality for ROS overproduction conditions in future medical practices.

Immune-mediated disruption of the blood-brain barrier after intracerebral hemorrhage: Insights and potential therapeutic targets

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.

Identification of Senescence-Related Biomarkers and Regulatory Networks in Intracerebral Hemorrhage

OBJECTIVES

Intracerebral hemorrhage (ICH) is a severe neurological disorder with substantial societal implications. Cellular senescence plays a critical role in ICH pathogenesis. This study aims to identify senescence-related biomarkers in ICH for diagnostic and therapeutic purposes.

METHODS

Raw data from GSE24265 in Gene Expression Omnibus was downloaded. Senescence-related genes were acquired from CellAge. Differential gene analysis was done between patients with ICH and controls. The intersection of ICH differentially expressed genes and senescence-related genes for senescence-related ICH genes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed. Protein-protein interaction network was constructed through the Search Tool for the Retrieval of Interacting Genes. Single sample gene set enrichment analysis was done for immune cell infiltration and function evaluation in control and ICH groups. miRWalk2.0 database was used for microRNA predictions targeting ICH biomarkers. Transcriptional regulatory relationships unraveled by sentence-based text mining database was employed to predict transcription factors regulating identified biomarkers.

RESULTS

Thirteen senescence-related ICH genes were identified. They were primarily enriched in the positive regulation of angiogenesis and the Advanced Glycation End Product -Receptor for AGE signaling pathway in diabetic complications. Validation in the GSE149317 data set and receiver operating characteristic analysis highlighted Caveolin 1, C-X-C Motif Chemokine Ligand 1, ETS proto-oncogene 1, transcription factor, and Serpin Family E Member 1 as potential ICH biomarkers. Single sample gene set enrichment analysis revealed increased Type 2 T helper cell 2_cells, Treg cells, and immune functions like Antigen-presenting cells_co_stimulation in patients with ICH. Fourteen microRNA, including has-miR-6728-3p, were predicted to regulate these biomarkers. transcription factors such as PPARG, RARA, HMGA1, and NFKB1 were identified as potential regulators of the ICH biomarkers.

CONCLUSION

Caveolin 1, C-X-C Motif Chemokine Ligand 1, ETS proto-oncogene 1, transcription factor, and Serpin Family E Member 1 may serve as valuable biomarkers in ICH. Targeting these genes could contribute to ICH prevention and treatment.

Engineered Antibodies to Improve Efficacy against Neurodegenerative Disorders

Antibodies that can selectively remove rogue proteins in the brain are an obvious choice to treat neurodegenerative disorders (NDs), but after decades of efforts, only two antibodies to treat Alzheimer's disease are approved, dozens are in the testing phase, and one was withdrawn, and the other halted, likely due to efficacy issues. However, these outcomes should have been evident since these antibodies cannot enter the brain sufficiently due to the blood-brain barrier (BBB) protectant. However, all products can be rejuvenated by binding them with transferrin, preferably as smaller fragments. This model can be tested quickly and at a low cost and should be applied to bapineuzumab, solanezumab, crenezumab, gantenerumab, aducanumab, lecanemab, donanemab, cinpanemab, and gantenerumab, and their fragments. This paper demonstrates that conjugating with transferrin does not alter the binding to brain proteins such as amyloid-β (Aβ) and α-synuclein. We also present a selection of conjugate designs that will allow cleavage upon entering the brain to prevent their exocytosis while keeping the fragments connected to enable optimal binding to proteins. The identified products can be readily tested and returned to patients with the lowest regulatory cost and delays. These engineered antibodies can be manufactured by recombinant engineering, preferably by mRNA technology, as a more affordable solution to meet the dire need to treat neurodegenerative disorders effectively.

The oxytocin receptor is essential for the protective effect of pair housing on post-stroke depression in mice

The beneficial effect of social interaction in mitigating the incidence of post-stroke depression (PSD) and ameliorating depressive symptoms has been consistently demonstrated through preclinical and clinical studies. However, the underlying relationship with oxytocin requires further investigation. In light of this, the present study aimed to explore the protective effect of pair housing on the development of PSD and the potential relationship with oxytocin receptors. The PSD model was induced by middle cerebral artery occlusion (MCAO) for 50 min, followed by 4-week isolated housing and restrained stress. Subsequently, each mouse in the pair-housing group (PH) was pair-housed with an isosexual healthy partner. Another group was continuously administrated fluoxetine (10 mg/Kg, i.p, once a day) for 3 weeks. To elucidate the potential role of oxytocin, we subjected pair-housed PSD mice to treatment with an oxytocin receptor (OXTR) antagonist (L368,889) (5 mg/Kg, i.p, once a day) for 3 weeks. At 31 to 32 days after MCAO, anxiety- and depressive-like behaviors were assessed using sucrose consumption, forced swim test, and tail-suspension test. The results showed that pair housing significantly improved post-stroke depression to an extent comparable to that of fluoxetine treatment. Furthermore, pair housing significantly decreased corticosterone in serum, increasing OXT mRNA expression in the hypothalamus. Treatment with L368,889 essentially reversed the effect of pair housing, with no discernible sex differences apart from changes in body weight. Pair housing increased hippocampal serotonin (5-HT), but treatment with L368,889 had no significant impact. Additionally, pair housing effectively reduced the number of reactive astrocytes and increased Nissl's body in the cortex and hippocampal CA3 regions. Correspondingly, treatment with L368,889 significantly reversed the changes in the Nissl's body and reactive astrocytes. Moreover, pair housing downregulated mRNA levels of TNF-α, IL-1β, and IL-6 in the cortex caused by PSD, which was also reversed by treatment with L368,889. In conclusion, pair housing protects against the development of PSD depending on OXT and OXTR in the brain, with no significant divergence based on sex. These findings provide valuable insights into the potential of social interaction and oxytocin as therapeutic targets for PSD. Further research into the underlying mechanisms of these effects may contribute to the development of novel treatments for PSD.

Peripheral cytokine interleukin-10 alleviates perihematomal edema after intracerebral hemorrhage via interleukin-10 receptor/JAK1/STAT3 signaling

AIMS

The extent of perihematomal edema following intracerebral hemorrhage (ICH) significantly impacts patient prognosis, and disruption of the blood-brain barrier (BBB) exacerbates perihematomal edema. However, the role of peripheral IL-10 in mitigating BBB disruption through pathways that link peripheral and central nervous system signals remains poorly understood.

METHODS

Recombinant IL-10 was administered to ICH model mice via caudal vein injection, an IL-10-inhibiting adeno-associated virus and an IL-10 receptor knockout plasmid were delivered intraventricularly, and neurobehavioral deficits, perihematomal edema, BBB disruption, and the expression of JAK1 and STAT3 were evaluated.

RESULTS

Our study demonstrated that the peripheral cytokine IL-10 mitigated BBB breakdown, perihematomal edema, and neurobehavioral deficits after ICH and that IL-10 deficiency reversed these effects, likely through the IL-10R/JAK1/STAT3 signaling pathway.

CONCLUSIONS

Peripheral IL-10 has the potential to reduce BBB damage and perihematomal edema following ICH and improve patient prognosis.

Inflammatory response in traumatic brain and spinal cord injury: The role of XCL1-XCR1 axis and T cells

BACKGROUND

Traumatic brain injury (TBI) and spinal cord injury (SCI) are acquired injuries to the central nervous system (CNS) caused by external forces that cause temporary or permanent sensory and motor impairments and the potential for long-term disability or even death. These conditions currently lack effective treatments and impose substantial physical, social, and economic burdens on millions of people and families worldwide. TBI and SCI involve intricate pathological mechanisms, and the inflammatory response contributes significantly to secondary injury in TBI and SCI. It plays a crucial role in prolonging the post-CNS trauma period and becomes a focal point for a potential therapeutic intervention. Previous research on the inflammatory response has traditionally concentrated on glial cells, such as astrocytes and microglia. However, increasing evidence highlights the crucial involvement of lymphocytes in the inflammatory response to CNS injury, particularly CD8+ T cells and NK cells, along with their downstream XCL1-XCR1 axis.

OBJECTIVE

This review aims to provide an overview of the role of the XCL1-XCR1 axis and the T-cell response in inflammation caused by TBI and SCI and identify potential targets for therapy.

METHODS

We conducted a comprehensive search of PubMed and Web of Science using relevant keywords related to the XCL1-XCR1 axis, T-cell response, TBI, and SCI.

RESULTS

This study examines the upstream and downstream pathways involved in inflammation caused by TBI and SCI, including interleukin-15 (IL-15), interleukin-12 (IL-12), CD8+ T cells, CD4+ T cells, NK cells, XCL1, XCR1+ dendritic cells, interferon-gamma (IFN-γ), helper T0 cells (Th0 cells), helper T1 cells (Th1 cells), and helper T17 cells (Th17 cells). We describe their proinflammatory effect in TBI and SCI.

CONCLUSIONS

The findings suggest that the XCL1-XCR1 axis and the T-cell response have great potential for preclinical investigations and treatments for TBI and SCI.

Jingfang granules protects against intracerebral hemorrhage by inhibiting neuroinflammation and protecting blood-brain barrier damage

Intracerebral hemorrhage (ICH) can induce intensive oxidative stress, neuroinflammation, and brain cell apoptosis. However, conventional methods for ICH treatment have many disadvantages. There is an urgent need for alternative, effective therapies with minimal side effects. Pharmacodynamics experiment, molecular docking, network pharmacology, and metabolomics were adopted to investigate the treatment and its mechanism of Jingfang Granules (JFG) in ICH. In this study, we investigated the therapeutic effects of JFG on ICH using behavioral, brain water content and Magnetic resonance imaging experiments. However, the key active component and targets of JFG remain unknown. Here we verified that JFG was beneficial to improve brain injury after ICH. A network pharmacology analysis revealed that the anti-inflammatory effect of JFG is predominantly mediated by its activation of the phosphatidylinositol 3-kinase (PI3K)/AKT pathway through Luteolin, (+)-Anomalin and Phaseol and their targeting of AKT1, tumor necrosis factorα (TNF-α), and interleukin-1β (IL-1β). Molecular docking analyses revealed an average affinity of -8.633 kcal/mol, indicating a binding strength of less than -5 kcal/mol. Metabolomic analysis showed that JFG exerted its therapeutic effect on ICH by regulating metabolic pathways, such as the metabolism of taurine and hypotaurine, biosynthesis of valine, leucine, and isoleucine. In conclusion, we demonstrated that JFG attenuated neuroinflammation and BBB injury subsequent to ICH by activating the PI3K/Akt signaling pathway.

[Relationship Between the Migration of Endogenous Neural Stem Cells and the Pattern of Change in Immune Cell Phenotypes in the Microenvironment After Intracerebral Hemorrhage in Rats]

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.

TAK1 inhibition mitigates intracerebral hemorrhage-induced brain injury through reduction of oxidative stress and neuronal pyroptosis via the NRF2 signaling pathway

Introduction

Intracerebral hemorrhage (ICH) often triggers oxidative stress through reactive oxygen species (ROS). Transforming growth factor-β-activated kinase 1 (TAK1) plays a pivotal role in regulating oxidative stress and inflammation across various diseases. 5Z-7-Oxozeaenol (OZ), a specific inhibitor of TAK1, has exhibited therapeutic effects in various conditions. However, the impact of OZ following ICH and its underlying molecular mechanisms remain elusive. This study aimed to explore the possible role of OZ in ICH and its underlying mechanisms by inhibiting oxidative stress-mediated pyroptosis.

Methods

Adult male Sprague-Dawley rats were subjected to an ICH model, followed by treatment with OZ. Neurobehavioral function, blood-brain barrier integrity, neuronal pyroptosis, and oxidative stress markers were assessed using various techniques including behavioral tests, immunofluorescence staining, western blotting, transmission electron microscopy, and biochemical assays.

Results

Our study revealed that OZ administration significantly inhibited phosphorylated TAK1 expression post-ICH. Furthermore, TAK1 blockade by OZ attenuated blood-brain barrier (BBB) disruption, neuroinflammation, and oxidative damage while enhancing neurobehavioral function. Mechanistically, OZ administration markedly reduced ROS production and oxidative stress by facilitating nuclear factor-erythroid 2-related factor 2 (NRF2) nuclear translocation. This was accompanied by a subsequent suppression of the NOD-like receptor protein 3 (NLRP3) activation-mediated inflammatory cascade and neuronal pyroptosis.

Discussion

Our findings highlight that OZ alleviates brain injury and oxidative stress-mediated pyroptosis via the NRF2 pathway. Inhibition of TAK1 emerges as a promising approach for managing ICH.

Current evidence of synaptic dysfunction after stroke: Cellular and molecular mechanisms

BACKGROUND

Stroke is an acute cerebrovascular disease in which brain tissue is damaged due to sudden obstruction of blood flow to the brain or the rupture of blood vessels in the brain, which can prompt ischemic or hemorrhagic stroke. After stroke onset, ischemia, hypoxia, infiltration of blood components into the brain parenchyma, and lysed cell fragments, among other factors, invariably increase blood-brain barrier (BBB) permeability, the inflammatory response, and brain edema. These changes lead to neuronal cell death and synaptic dysfunction, the latter of which poses a significant challenge to stroke treatment.

RESULTS

Synaptic dysfunction occurs in various ways after stroke and includes the following: damage to neuronal structures, accumulation of pathologic proteins in the cell body, decreased fluidity and release of synaptic vesicles, disruption of mitochondrial transport in synapses, activation of synaptic phagocytosis by microglia/macrophages and astrocytes, and a reduction in synapse formation.

CONCLUSIONS

This review summarizes the cellular and molecular mechanisms related to synapses and the protective effects of drugs or compounds and rehabilitation therapy on synapses in stroke according to recent research. Such an exploration will help to elucidate the relationship between stroke and synaptic damage and provide new insights into protecting synapses and restoring neurologic function.

Pathological mechanisms and future therapeutic directions of thrombin in intracerebral hemorrhage: a systematic review

Intracerebral hemorrhage (ICH), a common subtype of hemorrhagic stroke, often causes severe disability or death. ICH induces adverse events that might lead to secondary brain injury (SBI), and there is currently a lack of specific effective treatment strategies. To provide a new direction for SBI treatment post-ICH, the systematic review discussed how thrombin impacts secondary injury after ICH through several potentially deleterious or protective mechanisms. We included 39 studies and evaluated them using SYRCLE's ROB tool. Subsequently, we explored the potential molecular mechanisms of thrombin-mediated effects on SBI post-ICH in terms of inflammation, iron deposition, autophagy, and angiogenesis. Furthermore, we described the effects of thrombin in endothelial cells, astrocytes, pericytes, microglia, and neurons, as well as the harmful and beneficial effects of high and low thrombin concentrations on ICH. Finally, we concluded the current research status of thrombin therapy for ICH, which will provide a basis for the future clinical application of thrombin in the treatment of ICH.

Alteration of mechanical stresses in the murine brain by age and hemorrhagic stroke

Residual mechanical stresses, also known as solid stresses, emerge during rapid differential growth or remodeling of tissues, as observed in morphogenesis and tumor growth. While residual stresses typically dissipate in most healthy adult organs, as the growth rate decreases, high residual stresses have been reported in mature, healthy brains. However, the origins and consequences of residual mechanical stresses in the brain across health, aging, and disease remain poorly understood. Here, we utilized and validated a previously developed method to map residual mechanical stresses in the brains of mice across three age groups: 5-7 days, 8-12 weeks, and 22 months. We found that residual solid stress rapidly increases from 5-7 days to 8-12 weeks and remains high in mature 22 months mice brains. Three-dimensional mapping revealed unevenly distributed residual stresses from the anterior to posterior coronal brain sections. Since the brain is rich in negatively charged hyaluronic acid, we evaluated the contribution of charged extracellular matrix (ECM) constituents in maintaining solid stress levels. We found that lower ionic strength leads to elevated solid stresses, consistent with its unshielding effect and the subsequent expansion of charged ECM components. Lastly, we demonstrated that hemorrhagic stroke, accompanied by loss of cellular density, resulted in decreased residual stress in the murine brain. Our findings contribute to a better understanding of spatiotemporal alterations of residual solid stresses in healthy and diseased brains, a crucial step toward uncovering the biological and immunological consequences of this understudied mechanical phenotype in the brain.

A Prospective Cohort Study of Elevated Serum NLRP1 Levels to Prognosticate Neurological Outcome After Acute Intracerebral Hemorrhage at a Single Academic Institution

Background

Nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 1 (NLRP1) participates in neuroinflammation. This study aimed to identify serum NLRP as a potential prognostic biomarker of acute intracerebral hemorrhage (ICH).

Methods

This prospective cohort study enrolled 145 patients with supratentorial ICH and 51 healthy controls. Serum NLRP1 levels were quantified on admission of all 145 patients, on days 1, 3, 5, 7, and 10 after stroke in 51 of 145 patients and at entry into the study of controls. Poststroke 6-month modified Rankin Scale (mRS) scores of 3-6 signified a poor prognosis.

Results

Compared to controls, patients had prominently increased serum NLRP1 levels until day 10 after ICH, with the highest levels at days 1 and 3. Serum NLRP1 levels were independently correlated with National Institutes of Health Stroke Scale (NIHSS) scores, hematoma volume and six-month mRS scores, and independently predicted six-month bad prognosis. A linear relationship was observed between serum NLRP1 levels and the risk of poor prognosis in a restricted cubic spline. Under the receiver operating characteristic (ROC) curve, serum NLRP levels efficiently discriminated poor prognosis. Serum NLRP1, NIHSS, and hematoma volume were merged into a prognosis prediction model, which was portrayed using a nomogram. Good performance of the model was verified using calibration curve, decision curve, and ROC curve.

Conclusion

Serum NLRP1 levels are elevated during the early period following ICH and are independently related to hemorrhagic severity and poor prognosis, suggesting that serum NLRP1 may represent a promising prognostic biomarker of ICH.

Efficacy and safety of standardized Ginkgo biloba extract as adjuvant therapy for intracerebral hemorrhage in China: A systematic review and meta-analysis

Objective

The aim of this study was to systematically review the clinical efficacy and safety of standardized Ginkgo biloba extract (GBE) in the adjuvant treatment of intracerebral hemorrhage (ICH).

Methods

Relevant RCTs on GBE as adjuvant therapy for ICH were searched in seven Chinese and English databases. Data extraction of the included literature was performed after duplicate checking and screening, and Stata 15.1 software was applied for data analysis.

Results

With a total of 19 RCTs, the meta-analysis results showed that: Compared with conventional treatment alone, GBE combined with conventional treatment had a higher effective rate; NIHSS score and CSS score were lower; The residual hematoma was less. The volume of cerebral edema was smaller. ADL score was higher. MoCA score was higher. The serum levels of hs-CRP, TNF-α and IL-6 were lower; No significant difference was observed in the incidence of adverse reactions between conventional treatment alone and GBE combined with conventional treatment.

Conclusion

This study suggests that GBE as adjuvant therapy for ICH has better efficacy and is relatively safe compared with conventional treatment alone. However, due to the quality and quantity of included studies, further validation by more methodologically rigorous and multi-center studies with larger sample sizes is needed.

Role of dendritic cells in spinal cord injury

BACKGROUND

Inflammation can worsen spinal cord injury (SCI), with dendritic cells (DCs) playing a crucial role in the inflammatory response. They mediate T lymphocyte differentiation, activate microglia, and release cytokines like NT-3. Moreover, DCs can promote neural stem cell survival and guide them toward neuron differentiation, positively impacting SCI outcomes.

OBJECTIVE

This review aims to summarize the role of DCs in SCI-related inflammation and identify potential therapeutic targets for treating SCI.

METHODS

Literature in PubMed and Web of Science was reviewed using critical terms related to DCs and SCI.

RESULTS

The study indicates that DCs can activate microglia and astrocytes, promote T-cell differentiation, increase neurotrophin release at the injury site, and subsequently reduce secondary brain injury and enhance functional recovery in the spinal cord.

CONCLUSIONS

This review highlights the repair mechanisms of DCs and their potential therapeutic potential for SCI.

Deubiquitylating Enzyme OTUB1 Facilitates Neuronal Survival After Intracerebral Hemorrhage Via Inhibiting NF-κB-triggered Apoptotic Cascades

The deubiquitylase OTU domain-containing ubiquitin aldehyde-binding protein 1 (OTUB1) has been implicated in the pathogenesis of various human diseases. However, the molecular mechanism by which OTUB1 participates in the pathogenesis of intracerebral hemorrhage (ICH) remains elusive. In the present study, we established an autologous whole blood fusion-induced ICH model in C57BL/6 J mice. We showed that the upregulation of OTUB1 contributes to the attenuation of Nuclear factor kappa B (NF-κB) and its downstream apoptotic signaling after ICH. OTUB1 directly associates with NF-κB precursors p105 and p100 after ICH, leading to attenuated polyubiquitylation of p105 and p100. Moreover, we revealed that NF-κB signaling was modestly activated both in ICH tissues and hemin-exposed HT-22 neuronal cells, accompanied with the activation of NF-κB downstream pro-apoptotic signaling. Notably, overexpression of OTUB1 strongly inhibited hemin-induced NF-κB activation, whereas interference of OTUB1 led to the opposite effect. Finally, we revealed that lentiviral transduction of OTUB1 markedly ameliorated hemin-induced apoptotic signaling and HT-22 neuronal death. Collectively, these findings suggest that the upregulation of OTUB1 serves as a neuroprotective mechanism in antagonizing neuroinflammation-induced NF-κB signaling and neuronal death, shed new light on manipulating intracellular deubiquitylating pathways as novel interventive approaches against ICH-induced secondary neuronal damage and death.

Ion Channel Dysregulation Following Intracerebral Hemorrhage

Injury to the brain after intracerebral hemorrhage (ICH) results from numerous complex cellular mechanisms. At present, effective therapy for ICH is limited and a better understanding of the mechanisms of brain injury is necessary to improve prognosis. There is increasing evidence that ion channel dysregulation occurs at multiple stages in primary and secondary brain injury following ICH. Ion channels such as TWIK-related K+ channel 1, sulfonylurea 1 transient receptor potential melastatin 4 and glutamate-gated channels affect ion homeostasis in ICH. They in turn participate in the formation of brain edema, disruption of the blood-brain barrier, and the generation of neurotoxicity. In this review, we summarize the interaction between ions and ion channels, the effects of ion channel dysregulation, and we discuss some therapeutics based on ion-channel modulation following ICH.

Unveiling the Effects of Left Hemispheric Intracerebral Hemorrhage on Long-term Potentiation and Inflammation in the Bilateral Hippocampus: A Preclinical Study

OBJECTIVE

Changes in cognition and memory are common complications of intracerebral hemorrhage (ICH), although the exact cause of this phenomenon is still unknown. The objectives of our project were to assess the changes in long-term potentiation, inflammation, and cell damage in the bilateral hippocampus following striatal intracerebral hemorrhage at different time points.

MATERIALS AND METHODS

Unilateral ICH was induced in the striatum of 96 Wistar rats (6 control groups and 6 ICH groups). We measured changes in synaptic inputs in the bilateral hippocampus using the field potential recording method on days 3, 7, and 14 after ICH. After staining the section with hematoxylin, the volume and number of hippocampal cells were measured. The number of NF-κB positive cells was evaluated using the immunohistochemistry method.

RESULTS

There was a significant change in the amplitude and slope of the hippocampal excitatory potential in the ICH group compared to the sham group, but only on the 7th day after surgery. Specifically, the ipsilateral hippocampus in the ICH-7 group showed an increase in stimulation recording in 90 minutes compared to the sham-7 group (p<0.0001), while the contralateral hippocampus in the ICH-7 group exhibited a decrease in potential recording compared to the sham-7 group (p<0.0001). By day 14, the ICH group had a lower cell density in both the ipsilateral (p<0.05) and contralateral hippocampus (p<0.05) compared to the sham group, but there was no significant change in the hippocampal volume between the groups at any time interval. Furthermore, our immunohistochemical analysis revealed that the number of NF-kB-positive cells in both hemispheres of the ICH groups was significantly greater than that of the sham groups across all time intervals.

CONCLUSIONS

These findings suggest that striatal injury may lead to inflammation and cell death in the bilateral hippocampus, which can impair cognitive function after ICH.