ABSTRACT
Background: Viral encephalitis (VE) is one of the common diseases of children with intracranial infection, it has come on urgent, progress is fast, and the clinical features of severe cases may even lead to disability, death, and other serious adverse prognostic outcomes, so seek in early diagnosis and prognosis of efficiency of the relevant indicators to stop in time and take effective means to prevent the further development is of great significance. Neopterin (NPT), as a factor that plays an important role in the process of validation development, has been relatively rarely studied in children with VE. Methods: In this study, 127 cases of children with VE were retrieved from the TCGA database by bioinformatics, and their amplitude integrated electroencephalogram (AEEG) related information was collected at the same time. The neurodevelopmental status of VE children was evaluated according to the Gesell scale and divided into the good group (n=88) and the poor group (n=39). The differences in NPT expression and AEEG score between them were observed. In addition, the clinical data of 100 children without VE were screened from the database, and the differences in NPT expression and AEEG score between VE children and non-VE children were compared. The ROC curve was used to evaluate the clinical efficacy of NPT combined with AEEG in diagnosis and prognosis prediction. Kaplan-Meier was used to observe the effect of NPT high expression and low expression on poor prognosis of VE children.
ABSTRACT
Background Leucine-rich glioma inactivated 1 (LGI1) antibody-related autoimmune encephalitis is easily misdiagnosed clinically because of its complex and diverse clinical manifestations. We present two cases of LGI1 antibody-related encephalitis with negative imaging findings and perform a literature review on this disease entity. Case description The first case was that of a 60-year-old man who presented with involuntary movement of the paroxysmal right limb. The second case was that of a 66-year-old man who presented with hearing hallucinations, involuntary shaking of the right limb, and progressive cognitive impairment. Both patients in this study showed negative magnetic resonance imaging (MRI) results. Routine cerebrospinal fluid (CSF) and biochemical examinations showed no significant abnormalities, and positive LGI1 antibodies were detected in both the CSF and serum. Conclusion Based on our experience and the literature review, we recommend that LGI1 antibody-related encephalitis should be considered when faciobrachial dystonic seizures, acute and subacute-onset seizures, low serum sodium (possibly with low CSF chloride), and cognitive-psychiatric disorders are encountered, even in the absence of specific radiographic and altered CSF findings (AU)
Antecedentes La encefalitis autoinmunitaria relacionada con anticuerpos LGI1 puede ser fácilmente mal diagnosticada clínicamente debido a sus manifestaciones clínicas complejas y diversas. Presentamos dos casos de encefalitis relacionada con anticuerpos LGI1 con hallazgos de imágenes negativas y realizamos una revisión de la literatura sobre esta entidad patológica. Descripción de casos El primer caso fue el de un hombre de 60años que presentó movimientos involuntarios del miembro derecho paroxístico. El segundo caso fue el de un hombre de 66años que presentó alucinaciones auditivas, temblores involuntarios del miembro derecho y un deterioro cognitivo progresivo. Ambos pacientes en este estudio mostraron resultados negativos de imágenes por resonancia magnética (RM). Los exámenes rutinarios de líquido cefalorraquídeo (LCR) y bioquímicos no mostraron anomalías significativas, pero se detectaron anticuerpos LGI1 positivos en ambos: LCR y suero. Conclusión Basándonos en nuestra experiencia y en la revisión de la literatura, recomendamos considerar la posibilidad de encefalitis relacionada con anticuerpos LGI1 cuando aparezcan crisis distónicas faciobraquiales, convulsiones de inicio agudo o subagudo, hiponatremia (posiblemente con hipoclorhidria del LCR) y trastornos cognitivo-psiquiátricos, incluso en ausencia de hallazgos radiográficos específicos o modificaciones en el LCR (AU)
Subject(s)
Humans , Male , Middle Aged , Aged , Autoimmune Diseases of the Nervous System/complications , Autoimmune Diseases of the Nervous System/diagnostic imaging , Encephalitis/diagnostic imaging , Intracellular Signaling Peptides and Proteins , Magnetic Resonance Imaging , AutoantibodiesABSTRACT
BACKGROUND: Leucine-rich glioma inactivated 1 (LGI1) antibody-related autoimmune encephalitis is easily misdiagnosed clinically because of its complex and diverse clinical manifestations. We present two cases of LGI1 antibody-related encephalitis with negative imaging findings and perform a literature review on this disease entity. CASE DESCRIPTION: The first case was that of a 60-year-old man who presented with involuntary movement of the paroxysmal right limb. The second case was that of a 66-year-old man who presented with hearing hallucinations, involuntary shaking of the right limb, and progressive cognitive impairment. Both patients in this study showed negative magnetic resonance imaging (MRI) results. Routine cerebrospinal fluid (CSF) and biochemical examinations showed no significant abnormalities, and positive LGI1 antibodies were detected in both the CSF and serum. CONCLUSION: Based on our experience and the literature review, we recommend that LGI1 antibody-related encephalitis should be considered when faciobrachial dystonic seizures, acute and subacute-onset seizures, low serum sodium (possibly with low CSF chloride), and cognitive-psychiatric disorders are encountered, even in the absence of specific radiographic and altered CSF findings.
Subject(s)
Autoimmune Diseases of the Nervous System , Encephalitis , Glioma , Limbic Encephalitis , Male , Humans , Middle Aged , Aged , Leucine , Intracellular Signaling Peptides and Proteins , Autoantibodies , Limbic Encephalitis/diagnostic imaging , Encephalitis/diagnostic imaging , Magnetic Resonance Imaging/adverse effects , Seizures/etiology , Autoimmune Diseases of the Nervous System/diagnostic imaging , Autoimmune Diseases of the Nervous System/complications , Glioma/complicationsABSTRACT
Alzheimer's disease (AD) is a prevalent neurodegenerative disorder characterized by neuroinflammation. Dexmedetomidine (Dex) is known for its neuroprotective properties in clinical settings. In this study, we investigated the potential of Dex in protecting against neuroinflammation in an AD mouse model induced by amyloid-beta (Aß) injection. First, in the AD mouse model, Aß injection were administered, and the model was confirmed through behavioral tests, including the Morris water maze and Y-maze. Neuroinflammatory states in Aß-injected mice were assessed using hematoxylin and eosin staining and enzyme-linked immunosorbent assay. Expression levels of microRNA (miR)-204-3p and F-box/LRR-repeat protein 7 (FBXL7) in mouse tissues were determined through real-time quantitative polymerase chain reaction and Western blot. The binding interaction between miR-204-3p and FBXL7 was elucidated using dual-luciferase analysis. Aß-injected mice exhibited cognitive impairment, neuroinflammation, and downregulated miR-204-3p. Upregulation of miR-204-3p reduced inflammatory infiltration and mitigated neuroinflammation in Aß-injected mice. Dex treatment reduced inflammation in hippocampal tissues of Aß-injected mice. Dex treatment upregulated miR-204-3p, leading to suppressed FBXL7 expression in tissues. Inhibition of miR-204-3p or overexpression of FBXL7 reversed the alleviating effect of Dex on neuroinflammation in Aß-injected mice. Overall, Dex increased miR-204-3p expression, resulting in the inhibition of FBXL7, and subsequently alleviated neuroinflammation in Aß-injected mice.
Subject(s)
Alzheimer Disease , Dexmedetomidine , MicroRNAs , Animals , Mice , Alzheimer Disease/drug therapy , Alzheimer Disease/metabolism , Amyloid beta-Peptides/metabolism , Dexmedetomidine/pharmacology , MicroRNAs/metabolism , Neuroinflammatory Diseases/drug therapy , Neuroinflammatory Diseases/metabolism , F-Box Proteins/drug effects , F-Box Proteins/metabolismABSTRACT
The clearance function is essential for maintaining brain tissue homeostasis, and the glymphatic system is the main pathway for removing brain interstitial solutes. Aquaporin-4 (AQP4) is the most abundantly expressed aquaporin in the central nervous system (CNS) and is an integral component of the glymphatic system. In recent years, many studies have shown that AQP4 affects the morbidity and recovery process of CNS disorders through the glymphatic system, and AQP4 shows notable variability in CNS disorders and is part of the pathogenesis of these diseases. Therefore, there has been considerable interest in AQP4 as a potential and promising target for regulating and improving neurological impairment. This review aims to summarize the pathophysiological role that AQP4 plays in several CNS disorders by affecting the clearance function of the glymphatic system. The findings can contribute to a better understanding of the self-regulatory functions in CNS disorders that AQP4 were involved in and provide new therapeutic alternatives for incurable debilitating neurodegenerative disorders of CNS in the future.
Subject(s)
Central Nervous System Diseases , Glymphatic System , Humans , Aquaporin 4 , Brain/metabolism , Central Nervous System/metabolism , Central Nervous System Diseases/metabolismABSTRACT
Activated microglia are divided into pro-inflammatory and anti-inflammatory functional states. In anti-inflammatory state, activated microglia contribute to phagocytosis, neural repair and anti-inflammation. Nrf2 as a major endogenous regulator in hematoma clearance after intracerebral hemorrhage (ICH) has received much attention. This study aims to investigate the mechanism underlying Nrf2-mediated regulation of microglial phenotype and phagocytosis in hematoma clearance after ICH. In vitro experiments, BV-2 cells were assigned to normal group and administration group (Nrf2-siRNA, Nrf2 agonists Monascin and Xuezhikang). In vivo experiments, mice were divided into 5 groups: sham, ICH + vehicle, ICH + Nrf2-/-, ICH + Monascin and ICH + Xuezhikang. In vitro and in vivo, 72 h after administration of Monascin and Xuezhikang, the expression of Nrf2, inflammatory-associated factors such as Trem1, TNF-α and CD80, anti-inflammatory, neural repair and phagocytic associated factors such as Trem2, CD206 and BDNF were analyzed by the Western blot method. In vitro, fluorescent latex beads or erythrocytes were uptaken by BV-2 cells in order to study microglial phagocytic ability. In vivo, hemoglobin levels reflect the hematoma volume. In this study, Nrf2 agonists (Monascin and Xuezhikang) upregulated the expression of Trem2, CD206 and BDNF while decreased the expression of Trem1, TNF-α and CD80 both in vivo and in vitro. At the same time, after Monascin and Xuezhikang treatment, the phagocytic capacity of microglia increased in vitro, neurological deficits improved and hematoma volume lessened in vivo. These results were reversed in the Nrf2-siRNA or the Nrf2-/- mice. All these results indicated that Nrf2 enhanced hematoma clearance and neural repair, improved neurological outcomes through enhancing microglial phagocytosis and alleviating neuroinflammation.
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Objective: Long-term physical therapy helps to improve the motor symptoms of patients with Parkinson's disease, but the effectiveness is not clear. The purpose of this study was to evaluate the effect of long-term physical therapy on improving motor symptoms or daily activities in Parkinson's patients with drug use or discontinuation, as well as its impact on drug treatment dose. A subgroup analysis was conducted on different treatment methods to determine the most effective treatment method. Methods: The researchers independently searched databases, including PubMed, Medline, Embase, Ovid, Cochrane Library, and ISI Web of science. The search deadline was June 2022. A randomized controlled trial was conducted on Parkinson's disease patients with HY stages 1-3 who received continuous physical therapy for 6 months or more. Systematic evaluation and meta-analysis were carried out by using common clinical evaluation indicators, namely, MDS-UPDRS exercise score, daily activity (ADL) score, or LED dose. The quality of the literature was assessed using the modified Jadad scale of Cochrane's bias risk tool. Results: A total of 523 Parkinson's disease patients with HY stages of 1-3 were included in the study. The results showed that long-term physical therapy could improve patients' motor symptoms with combined antiparkinsonian drugs (Z = 2.61 and P = 0.009) and had a significant positive effect on the motor symptoms of patients with discontinued antiparkinsonian drugs (Z = 2.73 and P = 0.006). Meanwhile, it could reduce the LED dose of patients with Parkinson's disease. The difference was statistically significant (Z = 2.58 and P = 0.010). Conclusion: The results of this study indicated that physical therapy for at least 6 months or longer for patients with mild to moderate Parkinson's HY could effectively improve the motor symptoms of Parkinson's patients, whether or not combined with antiparkinson drugs. Meanwhile, long-term physical therapy reduced the LED dose of patients treated with drugs compared with patients in the control group who received short-term physical therapy, other types of intervention group, or no treatment.
Subject(s)
Parkinson Disease , Activities of Daily Living , Antiparkinson Agents/therapeutic use , Humans , Parkinson Disease/therapy , Physical Therapy Modalities , Randomized Controlled Trials as Topic , Treatment OutcomeABSTRACT
Microglia are the resident immune cells of the central nervous system (CNS). It is well established that microglia are activated and polarized to acquire different inflammatory phenotypes, either pro-inflammatory or anti-inflammatory phenotypes, which act as a critical component in the neuroinflammation following intracerebral hemorrhage (ICH). Microglia produce pro-inflammatory mediators at the early stages after ICH onset, anti-inflammatory microglia with neuroprotective effects appear to be suppressed. Previous research found that driving microglia towards an anti-inflammatory phenotype could restrict inflammation and engulf cellular debris. The principal objective of this review is to analyze the phenotypes and dynamic profiles of microglia as well as their shift in functional response following ICH. The results may further the understanding of the body's self-regulatory functions involving microglia following ICH. On this basis, suggestions for future clinical development and research are provided.
Subject(s)
Cerebral Hemorrhage/immunology , Microglia/physiology , AMP-Activated Protein Kinases/physiology , Blood-Brain Barrier , Cell Polarity , Glycogen Synthase Kinase 3 beta/physiology , Humans , Inflammation/etiology , MAP Kinase Signaling System/physiology , MicroRNAs/physiologyABSTRACT
Triggering receptor expressed on myeloid cells-1 (TREM-1) was found to be induced in the context of subarachnoid hemorrhage (SAH) before. This study further investigates its role in the development of SAH-induced early brain injury (EBI). Firstly, rats were randomly divided into Sham and SAH groups for analysis of temporal patterns and cellular localization of TREM-1. Secondly, TREM-1 intervention was administrated to produce Sham, vehicle, antagonist and agonist groups, for analyzing TREM-1, Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88) and NF-κB expressions at 24 h post-modeling, and EBI assessment at 24 h and 72 h. Thirdly, TLR4 inhibitor (TAK-242) was exploited to produce Sham, Sham+TAK-242, SAH, and SAH + TAK-242 groups to analyze the effects of TLR4 inhibition on TREM-1 induction and EBI evaluation at 72 h. Fourthly, the relationship of soluble TREM-1 (sTREM-1) levels in cerebrospinal fluid of SAH patients with Hunt-Hess grades were explored. The results showed that TREM-1 increased in the brain after experimental SAH (eSAH) early at 6 h and peaked at 48 h, which was found to be located in microglia and endothelial cells. TREM-1 inhibition attenuated EBI associated with TLR4/MyD88/NF-κB suppression, while enhancement had the opposite effects. Contrarily, TLR4 inhibition prevented TREM-1 induction and ameliorated EBI. In addition, sTREM-1 levels in SAH patients positively correlated with Hunt-Hess grades. Overall, the present study provides new evidence that TREM-1 increases dynamically in the brain after eSAH and it is located in microglia and endothelial cells, which may aggravate EBI by interacting with TLR4 pathway. And sTREM-1 in patients might act as a monitoring biomarker of EBI, providing new insights for future studies.
Subject(s)
Brain Injuries/metabolism , Brain Injuries/pathology , Subarachnoid Hemorrhage/metabolism , Subarachnoid Hemorrhage/pathology , Triggering Receptor Expressed on Myeloid Cells-1/metabolism , Aged , Animals , Blood-Brain Barrier/metabolism , Blood-Brain Barrier/pathology , Brain/metabolism , Brain/pathology , Endothelial Cells/metabolism , Endothelial Cells/pathology , Female , Humans , Male , Microglia/metabolism , Microglia/pathology , Middle Aged , Rats , Rats, Sprague-Dawley , Time FactorsABSTRACT
Oxidative stress (OS) is induced by the accumulation of reactive oxygen species (ROS) following intracerebral hemorrhage (ICH) and plays an important role in secondary brain injury caused by the inflammatory response, apoptosis, autophagy, and blood-brain barrier (BBB) disruption. This review summarizes the current state of knowledge regarding the pathogenic mechanisms of brain injury after ICH, markers for detecting OS, and therapeutic strategies that target OS to mitigate brain injury.
Subject(s)
Cerebral Hemorrhage/drug therapy , Cerebral Hemorrhage/pathology , Oxidative Stress , Animals , Biomarkers/metabolism , Humans , Models, Biological , Molecular Targeted Therapy , Reactive Oxygen Species/metabolismABSTRACT
As the most metabolically active organ in the body, there is a recognized need for pathways that remove waste proteins and neurotoxins from the brain. Previous research has indicated potential associations between the clearance system in the brain and the pathological conditions of the central nervous system (CNS), due to its importance, which has attracted considerable attention recently. In the last decade, studies of the clearance system have been restricted to the glymphatic system. However, removal of toxic and catabolic waste by-products cannot be completed independently by the glymphatic system, while no known research or article has focused on a comprehensive overview of the structure and function of the clearance system. This thesis addresses a neglected aspect of linkage between the structural composition and main components as well as the role of neural cells throughout the clearance system, which found evidence that the components of CNS including the glymphatic system and the meningeal lymphatic system interact with a neural cell, such as astrocytes and microglia, to carry out vital clearance functions. As a result of this evidence that can contribute to a better understanding of the clearance system, suggestions were identified for further clinical intervention development of severe conditions caused by the accumulation of metabolic waste products and neurotoxins in the brain, such as Alzheimer's disease (AD) and Parkinson's disease (PD).
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Ferroptosis is a term that describes one form of regulated non-apoptotic cell death. It is triggered by the iron-dependent accumulation of lipid peroxides. Emerging evidence suggests a link between ferroptosis and the pathophysiological processes of neurological disorders, including stroke, degenerative diseases, neurotrauma, and cancer. Hemorrhagic stroke, also known as intracerebral hemorrhage (ICH), belongs to a devastating illness for its high level in morbidity and mortality. Currently, there are few established treatments and limited knowledge about the mechanisms of post-ICH neuronal death. The secondary brain damage after ICH is mainly attributed to oxidative stress and hemoglobin lysate, including iron, which leads to irreversible damage to neurons. Therefore, ferroptosis is becoming a common trend in research of neuronal death after ICH. Accumulative data suggest that the inhibition of ferroptosis may effectively prevent neuronal ferroptosis, thereby reducing secondary brain damage after ICH in animal models. Ferroptosis has a close relationship with oxidative damage and iron metabolism. This review reveals the pathological pathways and regulation mechanism of ferroptosis following ICH and then offers potential intervention strategies to mitigate neuron death and dysfunction after ICH.
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Meningiomas are common intracranial tumors that can be cured by surgical resection in most cases. However, the most disconcerting is high-grade meningiomas, which frequently recur despite initial successful treatment, eventually conferring poor prognosis. Therefore, the early diagnosis and classification of meningioma is necessary for the subsequent intervention and an improved prognosis. A growing body of evidence demonstrates the potential of multi-omics study (including genomics, transcriptomics, epigenomics, proteomics) for meningioma diagnosis and mechanistic links to potential pathological mechanism. This thesis addresses a neglected aspect of recent advances in the field of meningiomas at multiple omics levels, highlighting that the integration of multi-omics can reveal the mechanism of meningiomas, which provides a timely and necessary scientific basis for the treatment of meningiomas.
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The interaction between microglia and astrocytes significantly influences neuroinflammation. Microglia/astrocytes, part of the neurovascular unit (NVU), are activated by various brain insults. The local extracellular and intracellular signals determine their characteristics and switch of phenotypes. Microglia and astrocytes are activated into two polarization states: the pro-inflammatory phenotype (M1 and A1) and the anti-inflammatory phenotype (M2 and A2). During neuroinflammation, induced by stroke or lipopolysaccharides, microglia are more sensitive to pathogens, or damage; they are thus initially activated into the M1 phenotype and produce common inflammatory signals such as IL-1 and TNF-α to trigger reactive astrocytes into the A1 phenotype. These inflammatory signals can be amplified not only by the self-feedback loop of microglial activation but also by the unique anatomy structure of astrocytes. As the pathology further progresses, resulting in local environmental changes, M1-like microglia switch to the M2 phenotype, and M2 crosstalk with A2. While astrocytes communicate simultaneously with neurons and blood vessels to maintain the function of neurons and the blood-brain barrier (BBB), their subtle changes may be identified and responded by astrocytes, and possibly transferred to microglia. Although both microglia and astrocytes have different functional characteristics, they can achieve immune "optimization" through their mutual communication and cooperation in the NVU and build a cascaded immune network of amplification.
Subject(s)
Astrocytes/immunology , Brain/physiology , Microglia/immunology , Neurogenic Inflammation/immunology , Neurons/physiology , Neurovascular Coupling/physiology , Animals , Humans , Inflammation Mediators/metabolismABSTRACT
BACKGROUND: Hematoma is the chief culprit in brain injury following intracranial cerebral hemorrhage (ICH). Noninvasive hematoma clearance could be an option to prevent and alleviate early brain injury after ICH. Peroxisome proliferator-activated receptor γ (PPAR-γ) and nuclear factor-erythroid 2 related factor-2 (Nrf2) facilitate removal of hematoma in ICH. Monascin acts as the natural Nrf2 activator with PPAR-γ agonist, and the long-term effects of monascin following ICH have not been elucidated. METHODS: ICH in rats was induced by stereotactic, intrastriatal injection of type IV collagenase. Monascin was administered twice daily by gastric perfusion for 14 days after ICH induction. Long-term neurological scores (T maze, Garcia scales, rotor rod test, and Morris water maze), hematoma volume, as well as iron overload around hematoma and brain atrophy were evaluated at 7, 14, and 28 days after ICH. RESULTS: The results showed that monascin improved long-term neurological deficits, spatial memory performance, learning ability, and brain shrinkage after ICH. Monascin also reduced hematoma volume at 7 days and iron content at 7 and 14 days after ICH. CONCLUSION: PPAR γ and Nrf2 play a crucial role in hematoma clearance after ICH in rat. As a dual agonist of PPAR γ and Nrf2, monascin improved long-term outcomes by facilitating hematoma clearance, and by attenuating iron overload and brain atrophy after experimental ICH.
ABSTRACT
Early brain injury (EBI) mainly leads to the poor outcome of subarachnoid hemorrhage (SAH), with which inflammation is closely associated. It was reported that triggering receptor expressed on myeloid cells-1 (TREM-1), a critical inflammatory amplifier, increased in cerebrospinal fluid of SAH patients in our recent research. This study was conducted to examine the effects of TREM-1 inhibition on EBI after experimental SAH (eSAH). The endovascular perforation model of SAH was produced and 120 rats were randomly divided into four groups as sham, SAHâ¯+â¯vehicle and SAHâ¯+â¯LP17 (1.0â¯mg/kg and 3.5â¯mg/kg). The LP17, a selective inhibitor of TREM-1, or vehicle was administered by an intraperitoneal injection 1â¯h post-modeling. Western blot analysis for TREM-1, p38 mitogen-activated protein kinase (p38MAPK), matrix metalloproteinase-9 (MMP-9) and zonula occludens-1 (ZO-1) was conducted at 24â¯h post-modeling. EBI was assessed in terms of mortality, neuroscore, brain edema, blood-brain barrier (BBB) disruption in 24 and 72â¯h. The results showed that TREM-1 was induced in brain after eSAH. Both high dose (3.5â¯mg/kg) and low dose (1.0â¯mg/kg) of Lp17 significantly inhibited the induction of TREM-1, but only high dose of LP17 improved neuroscore, brain edema, and BBB disruption which are associated with downregulation of p38MAPK/MMP-9 and subsequent preservation of ZO-1. Overall, the current study provides new evidence that TREM-1 may participate in the pathogenesis of SAH-induced EBI via promoting p38MAPK/MMP-9 activation and ZO-1 degradation, while TREM-1 inhibition attenuated the EBI severity obviously, providing a novel approach for the treatment of EBI.
Subject(s)
Brain Injuries/metabolism , Matrix Metalloproteinase 9/metabolism , Subarachnoid Hemorrhage/metabolism , Tight Junctions/metabolism , Triggering Receptor Expressed on Myeloid Cells-1/metabolism , p38 Mitogen-Activated Protein Kinases/metabolism , Animals , Brain Injuries/prevention & control , Down-Regulation/drug effects , Down-Regulation/physiology , Male , Random Allocation , Rats , Rats, Sprague-Dawley , Subarachnoid Hemorrhage/prevention & control , Tight Junctions/drug effects , Triggering Receptor Expressed on Myeloid Cells-1/antagonists & inhibitors , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitorsABSTRACT
The role of vitamin D3 (VitD3) in the upregulation of osteopontin (OPN) and eNOS in the endothelium of cerebral arteries after subarachnoid hemorrhage (SAH) is investigated. The endovascular perforation SAH model in Sprague-Dawley rats ( n = 103) was used. The VitD3 pretreatment (30 ng/kg) increased endogenous OPN and eNOS expression in cerebral arteries compared with naïve rats ( n = 5 per group). Neurobehavioral scores were significantly improved in Pre-SAH+VitD3 group compared with the SAH group. The effects of VitD3 were attenuated by intracerebroventricular (i.c.v) injections of siRNA for the vitamin D receptor (VDR) and OPN in Pre-SAH+VitD3+VDR siRNA and Pre-SAH+VitD3+OPN siRNA rats, respectively ( n = 5 per group). The significant increase of VDR, OPN and decrease of C44 splicing in the cerebral arteries of Pre-SAH+VitD3 rats lead to an increase in basilar artery lumen. The increase in VDR expression led to an upregulation and phosphorylation of AMPK and eNOS, especially dimer form, in endothelium of cerebral artery. The results provide that VitD3 pretreatment attenuates cerebral artery remodeling and vasospasm through the upregulation of OPN and phosphorylation of AMPK (p-AMPK) and eNOS (p-eNOS) at Ser1177-Dimer in the cerebral arteries. Vitamin D may be a useful new preventive and therapeutic strategy against cerebral artery remodeling in stroke patients.
Subject(s)
AMP-Activated Protein Kinases/metabolism , Cerebral Arteries/metabolism , Cholecalciferol/pharmacology , Nitric Oxide Synthase Type III/metabolism , Protein Multimerization/drug effects , Receptors, Calcitriol/biosynthesis , Subarachnoid Hemorrhage/metabolism , Vascular Remodeling/drug effects , Animals , Cerebral Arteries/pathology , Cerebral Arteries/physiopathology , Male , Osteopontin/metabolism , Phosphorylation/drug effects , Rats , Rats, Sprague-Dawley , Subarachnoid Hemorrhage/pathology , Subarachnoid Hemorrhage/physiopathology , Up-Regulation/drug effects , Vasospasm, Intracranial/metabolism , Vasospasm, Intracranial/pathology , Vasospasm, Intracranial/physiopathologyABSTRACT
Background and Purpose- Heme and iron are considered to be key factors responsible for secondary insults after intracerebral hemorrhage (ICH). Our previous study showed that LRP1 (low-density lipoprotein receptor-related protein-1)-Hx (hemopexin) facilitates removal of heme. The TLR7 (Toll-like receptor 7)-BTK (Bruton tyrosine kinase)-CRT (calreticulin) pathway regulates the expression of LRP1-Hx. This study is designed to clarify whether TLR7 activation facilitates heme scavenging and to establish the potential role of the BTK-CRT-LRP1-Hx signaling pathway in the pathophysiology of ICH. Methods- ICH was induced by stereotactic, intrastriatal injection of type VII collagenase. Mice received TLR7 agonist (imiquimod) via intraperitoneal injection after ICH induction. TLR7 inhibitor (ODN2088), BTK inhibitor (LFM-A13), and CRT agonist (thapsigargin) were given in different groups to further evaluate the underlying pathway. Mice were randomly divided into sham, ICH+vehicle (normal saline), ICH+Imiquimod (2.5, 5, and 10 µg/g), ICH+ODN2088, ICH+LFM-A13, ICH+thapsigargin, and ICH+ODN2088+thapsigargin. Imiquimod was administered twice daily starting at 6 hours after ICH; ODN2088 was administered by intracerebroventricular injection at 30 minutes, and LFM-A13 or thapsigargin was administered by intraperitoneal injection at 3 hours after ICH induction. Neurological scores, cognitive abilities, as well as brain edema, blood-brain barrier permeability, hemoglobin level, brain expression of TLR7/BTK/CRT/LRP1/Hx were analyzed. Results- Low dosage imiquimod significantly attenuated hematoma volume, brain edema, BBB permeability, and neurological deficits after ICH. Imiquimod also increased protein expressions of TLR7, BTK, CRT, LRP1, and Hx; ODN2088 reduced TLR7, BTK, CRT, LRP1, and Hx expressions. Conclusions- TLR7 plays an important role in heme scavenging after ICH by modulating the BTK-CRT-LRP1-Hx pathway. TLR7 may offer protective effects by promoting heme resolution and reduction of brain edema after ICH.