Microglia are brain immune cells that maintain homeostasis and respond to injury, changing cell morphology to drive inflammation, migration, and phagocytosis. This study examined the role of the kinesin KIF21B in microglial activation, demonstrating for the first time its expression in microglial cells in two in vivo neuroinflammatory models: TBI (focal inflammation) and LPS administration (diffuse inflammation). While TBI provoked a significant increase in KIF21B/Iba1 colocalization in the tissue around the lesion exclusively in females, LPS administration did not alter KIF21B expression in either sex. Given the importance of cytoskeleton remodeling for microglial migration and phagocytosis, this work investigates whether KIF21B contributes to these actions. Downregulating KIF21B in primary cultured mouse microglia had sex-specific effects. In females, KIF21B silencing reduced both migratory capacity and phagocytosis of E. coli-coated spheres and neuronal debris. In males, it exacerbated migration and selectively increased neuronal debris phagocytosis, while E. coli-coated sphere uptake remained unaffected. These functional differences were accompanied by sex-dependent morphological alterations, quantified through area, circularity, Feret's diameter, and perimeter: KIF21B silencing blocked the transition to amoeboid morphology in females while inducing hyperpolarized elongation in males. Finally, LPS treatment increased KIF21B colocalization with microtubules and reduced its colocalization with F-actin in females, while neither interaction was significantly altered in males. Overall, the findings suggest that KIF21B regulates microglial function in a sex-dependent manner through its effects on cytoskeletal organization.
Overcoming remyelination failure is one of the main targets in therapeutic strategies for multiple sclerosis. This process requires the differentiation of oligodendrocyte precursor cells (OPCs) to mature myelinating oligodendrocytes (OLs), a process known to be controlled by thyroid hormone, nuclear receptors, and sonic hedgehog (SHH). Retinoid X receptor gamma (RXRg) is one of the nuclear receptors acting as a positive regulator of remyelination, but little is known about its mechanisms of function. Using transcriptomic and pharmacological analysis of primary neural stem cell-derived OPCs, we show that RXRg is involved in the induction of the thyroid hormone-driven differentiation process and in refining it toward an oligodendrogenic cell fate. RXRg also emerged as an important negative modulator of SHH expression and signaling, as Shh and additional genes from this pathway were found to be strongly upregulated in Rxrg -/- OPCs. An inhibition of SHH signaling by cyclopamine or GANT61 entirely normalized the differentiation deficit of Rxrg -/- OPCs, but also myelination of newly generated Rxrg -/- OLs. Such data indicate a key role of SHH hyperactivity in the oligodendrogenesis block associated with the absence of RXRg. Importantly, hyperactivation of the SHH pathway by purmorphamine or SAG inhibited the oligodendrogenesis and myelination potential of wild-type OPCs, indicating that SHH hyperactivity can also be a sufficient factor to block OPC differentiation. These results point to RXRg as an important regulator of SHH pathway signaling and underline the need of an optimal, fine-tuning of SHH signaling to assure successful oligodendrogenesis.
Background Stroke remains a leading global cause of mortality and disability, with optimal outcomes dependent on rapid risk identification, precise acute management, tailored interventions, and sustained rehabilitation. Digital twins, which are dynamic computational replicas of individual patients integrating multimodal data and mechanistic models, represent an innovative approach to simulating disease trajectories and treatment responses before real world implementation. Aim This narrative review synthesises current evidence on digital twin applications across the stroke care continuum, examining their role in risk prediction, acute decision support, clinical trial optimisation, intensive care monitoring, and personalised neurorehabilitation. Method We explored publications from PubMed, Nature Portfolio journals, IEEE and ACM databases spanning 2021 to 2025, identifying relevant publications across technical, clinical, and implementation dimensions. Search terms combined “digital twin” with stroke-specific and enabling-technology terminology. The review integrates findings across technical, clinical, and implementation dimensions to provide a holistic perspective on this rapidly evolving field. Results Emerging evidence demonstrates feasibility and early clinical utility of digital twins across multiple stroke phases. Applications include atrial fibrillation related embolic risk stratification through patient specific left atrial modelling, imaging informed cerebrovascular hemodynamics for acute triage, disease digital twin generators for trial enrichment, and robotic rehabilitation systems with adaptive learning. However, most studies remain at preclinical or early pilot stages, with few meeting strict real-time digital twin criteria requiring bidirectional data flow and continuous updating. Conclusion Digital twins offer transformative potential for stroke care through personalised risk assessment, hyperacute decision support, and adaptive rehabilitation. Translation to routine practice requires rigorous prospective validation, standardised data models, robust governance frameworks, and demonstrated clinical utility across diverse populations. A clear translational roadmap, from current component technologies to fully closed-loop systems, is essential to guide investment and prioritise research.
Cortical demyelination is a critical contributor to progressive disease in multiple sclerosis (MS). The barriers to cortical remyelination following demyelination are not fully understood, and there are no remyelinating treatments for MS. We previously took advantage of the spatial and temporal resolution of longitudinal in vivo imaging to study cortical oligodendrocyte regeneration following cuprizone-induced demyelination and found that oligodendrocyte regeneration was impaired. In this study, we investigated whether cortical reactive microglia disrupt oligodendrocyte regeneration. To do so, we used a combination of in situ RNA and immunofluorescence labeling to characterize cortical microglia reactive states following cuprizone-mediated demyelination. We then depleted cortical microglia by administering a Csf1r inhibitor during the recovery period from cuprizone and quantified oligodendrocyte recovery. We found that following cortical demyelination, deep cortical microglia change morphology, downregulate homeostatic markers (P2RY12, TMEM119), and upregulate a marker (CD68) associated with activated macrophages. These reactive changes persisted through early recovery post-cuprizone but resolved by late recovery. Depleting cortical microglia post-cuprizone restored the baseline density of deep cortical ASPA+ oligodendrocytes at early and late recovery. There were also more deep cortical BCAS1+ differentiating oligodendrocytes at early recovery when microglia were depleted, suggesting that transient deep cortical reactive microglia impair oligodendrocyte differentiation following demyelinating injury. Together, we found that cortical microglia adopt spatially restricted reactive functions after demyelination and deep cortical reactive microglia transiently reduce differentiating oligodendrocytes. A potential therapeutic strategy for progressive MS could involve targeting transiently reactive microglia at the right time and place in cortical lesions to promote oligodendrocyte regeneration.
Oligodendrocytes, traditionally recognized for their role in central nervous system myelination, have emerged during the last decades as key participants maintaining brain homeostasis in response to metabolic demands and stress. In addition, injury to myelin prompts a regenerative response that leads to the formation of new myelin sheaths. However, the signals regulating effective remyelination by oligodendrocytes are still not completely understood. Here, we report that oligodendrocytes can internalize exogenous myelin both in vitro and in vivo, which leads to an increase in oligodendroglial lineage progression. RNA sequencing reveals that myelin debris alters the oligodendrocyte transcriptional profile, leading to the suppression of immune-related pathways and de novo cholesterol and fatty acid biosynthesis, while promoting lipid droplet formation for the storage and processing internalized myelin particles. In primary cultures, myelin exposure increases oligodendrocyte progenitor (OPC) proliferation and overall oligodendroglia lineage progression, accompanied by greater cellular complexity and a larger myelinated area per cell, without altering the relative OPC-to-mature oligodendrocyte ratio. Stereotaxic injection of fluorescent myelin into mouse cortex and zebrafish ventricles shows internalization by microglia and, to a lesser extent, by oligodendroglia. Notably, in the zebrafish model, ventricular injections of myelin also increase the number of ventral oligodendrocytes in the spinal cord, further supporting that myelin can promote lineage progression. These findings challenge the classical view that myelin debris intrinsically inhibits oligodendrocyte proliferation, suggesting instead that oligodendrocytes can use myelin to support self-renewal and maturation across vertebrate species, acting as a trophic factor in the absence of pathological cues.
Objective: Accurate identification of intracranial hemorrhage (ICH) subtypes on non-contrast CT is crucial for prognosis and treatment but remains challenging due to low contrast and blurred boundaries. This study evaluates the zero-shot performance of multi-modal large language models (MLLMs) versus traditional deep learning in ICH detection and subtyping. Methods: Using 192 NCCT volumes from the RSNA dataset, we compared MLLMs (GPT-4o, Gemini 2.0 Flash, Claude 3.5 Sonnet V2) with deep learning models (ResNet50, Vision Transformer). MLLMs were prompted for ICH presence, subtype, localization, and volume estimation. Results: Traditional deep learning models outperformed MLLMs in both ICH detection and subtyping. For subtyping, MLLMs showed lower accuracy, with Gemini 2.0 Flash achieving a macro-averaged precision of 0.41 and F1 score of 0.31. Conclusion: While MLLMs offer enhanced interpretability through language-based interaction, their accuracy in ICH subtyping remains inferior to deep learning networks. Further optimization is needed to improve their utility in three-dimensional medical imaging.
Hypertension is a major cause of cerebral hemorrhage. Although they are widely used in preclinical studies on cerebral hemorrhage, traditional in vivo cerebrovascular imaging techniques, such as positron emission tomography and magnetic resonance imaging, often fall short in dynamically visualizing cerebral microcirculation blood flow in rodent models. This study leveraged the high spatiotemporal resolution of multimodal ultrafast sonography microscopy (MUSM) to assess cerebrovascular hemodynamics in vivo within hypertensive mice induced by Angiotensin II (Ang II) and Nω-nitro-L-arginine methyl ester (L-NAME). Cerebrovascular hemodynamics were quantified using variations in cerebral vascular density, diameter, velocity, tortuosity, cerebral flow pulsatility, and instant flow direction. Our findings revealed a decrease in cerebral vascular density and perfusion index after blood pressure increased, particularly in the cortex and basal ganglia regions. This study not only provides a comprehensive view of cerebral dynamics in hypertension but also introduces MUSM as a novel tool for in vivo cerebrovascular hemodynamic analysis in preclinical animal research.
Objective: This systematic review and meta-analysis evaluated the efficacy and safety of robot-assisted surgery for primary brainstem hemorrhage (PBSH). Methods: Using the PICO framework, we compared robot-assisted surgery with conventional medical therapy regarding postoperative rebleeding, mortality, favourable functional outcomes, complications, and hematoma evacuation. A systematic search of PubMed, Web of Science, Embase, and the Cochrane Library was performed through July 2025, supplemented by manual citation screening. All five included studies were retrospective cohort studies. Results: Qualitative synthesis indicated that robotic approaches achieved more precise hematoma clearance, better neurological recovery, and fewer complications compared with conservative therapy. Meta-analyses demonstrated reduced postoperative rebleeding and mortality with robot-assisted interventions. However, analyses of favourable functional outcomes and length of hospital stay demonstrated substantial heterogeneity, limiting pooled estimates. Notably, many survivors after robotic evacuation had substantial disability. Conclusion: Overall, current evidence suggests that robot-assisted neurosurgery offers promising clinical benefits over conventional management in selected PBSH patients, particularly in reducing mortality. The ethical implications of life-prolonging intervention that results in substantial disability warrant discussion. Further multicentre, high-quality prospective trials are warranted to confirm these findings and refine patient selection criteria.
Neuroinflammation mediated by microglia and astrocytes is a major component of traumatic brain injury (TBI) pathophysiology. The sterile alpha and TIR motif containing 1 (SARM1) protein has been identified to play a key role in neurodegeneration and inflammatory cascades. Therefore, we hypothesized that the inhibition of SARM1 would prevent glial reactivity following TBI and could be targeted for therapeutic intervention. TBI was modeled in wild type (WT) and SARM1 knock-out (SARM1-KO) mice of both biological sexes by midline fluid percussion injury. At 7 or 28 days post-injury, brains were collected to examine glial reactivity via immunohistochemistry and compared to naïve controls. The density of microglia and glial fibrillary acidic protein (GFAP) immunoreactivity of astrocytes was significantly increased across time post-injury. Furthermore, microglial morphological changes and increased colocalization with a surrogate marker of phagocytosis (CD68) were evident at 7 days post-injury. In the absence of SARM1, microglial density and colocalization with CD68 was greater compared with WT animals, regardless of TBI. However, there were no differences in GFAP immunoreactivity with the genetic deletion of SARM1. When investigating biological sexes, the TBI-induced increase in microglial density and cell volume was greater in male mice at 7 days post-injury; however, microglia were more deramified in females. There were no significant differences in GFAP immunoreactivity between male and female mice. These results indicate that the genetic deletion of SARM1 is not sufficient to alter GFAP-labeling of astrocytes; however, SARM1 appears to impact microglial density and CD68 colocalization in the naïve and injured brain.
THY1 is a cell surface protein of mature neurons. Although the Thy1 promoter is widely used as a neuron-specific promoter for transgenic expression, the role of the endogenous THY1 protein in the brain remains largely unknown. As THY1 receptors are expressed on astrocytes, THY1 may mediate signaling between both cell types. We therefore investigated the role of THY1 signaling in neuron-astrocyte communication using a full as well as a neuron-specific Thy1-knockout mouse model. Compared to wild-type mice, aged individuals of both strains exhibited an increased expression of a subset of astrocyte activation-associated genes, such as glial fibrillary acidic protein (Gfap), vimentin (Vim), and tenascin C (Tnc), whereas others appeared unaffected. Importantly, a cortical injury caused a permanent astrocytic activation in mice with neuronal Thy1 deletion, reflected by persistent high GFAP expression. The THY1-associated modulation of gene expression was confirmed in primary astrocytes cultured with or without recombinant THY1. Moreover, functional assays indicate that THY1 inhibits astrocyte proliferation while promoting apoptosis. Interaction of neuronal THY1 with ITGB1 on astrocytes was identified to be responsible for the THY1-mediated control of astrocyte activation. These data strongly suggest that THY1-bearing neurons keep astrocytes in a quiescent state. Consequently, a depletion of THY1 supports the development of a partially activated astrocyte phenotype characterized by increased expression of intermediate filaments, increased proliferative capacity, and reduced cell death. Our findings demonstrate that neuronal THY1 is a still unrecognized novel regulator in the communication between astrocytes and neurons involved in the maintenance and restoration of tissue homeostasis in the brain.
Spinal cord injury (SCI) results in significant disruption of nerve fibers responsible for transmitting signals between the brain and body, often leading to partial or complete motor, sensory, and autonomic dysfunction below the injury site. Astrocytes are an important component in scar formation, crucial for suppression of injury propagation, effective wound healing, and the regulation of neuronal plasticity. Here, we identify the role of the actin-binding protein Drebrin (DBN) in reactive astrogliosis following SCI. SCI induces the upregulation of DBN in astrocytes, which controls immediate injury containment but also the long-term preservation of tissue integrity and healing in the spinal cord. DBN knockout results in enlarged spinal cord lesions, increased immune cell infiltration, and neurodegeneration. Mechanistically, DBN loss disrupts the polarization of scar border-forming astrocytes, leading to impaired encapsulation of the injury. In summary, DBN serves as a pivotal regulator of SCI outcome by modulating astrocytic polarity, which is essential for establishing a protective barrier confining the lesion site.
After high-level spinal cord injury (SCI), persistently reactive microglia drive widespread plasticity throughout the neuraxis. Plasticity in the thoracolumbar cord, a region corresponding to the spinal sympathetic reflex (SSR) circuit, contributes to the development of sympathetic dysfunction and associated immune disorders. The transcription factor NF-κB is activated after SCI, promoting a pro-inflammatory loop by driving the expression of inflammatory mediators which further activate NF-κB signaling. We hypothesize that microglial NF-κB signaling via IKKβ modulates microglial activity, impacting central and peripheral immune activity related to the SSR circuit post-SCI. We assessed the effect of deleting canonical IKKβ in CNS-resident microglia, its impact on microglial activation, polarization, central transcriptional activity, and peripheral immune activity at 1- and 4-week post-SCI (wpi). Transcriptomic analyses reveal microglial IKKβ influences immune-related pathways in the thoracolumbar cord at 1 wpi. We show that inhibition of microglial NF-κB signaling via deletion of the activator IKKβ mitigates injury-induced increases in "proinflammatory" M1 microglia in the thoracolumbar cord at 4 wpi and increases the quantity of splenocytes at 1 wpi. This study advances our understanding of how microglial IKKβ signaling shapes the neuroimmune response and a peripheral immune organ after SCI.
Chronic neuroinflammation, driven by central nervous system (CNS)-resident astrocytes and microglia, as well as infiltration of the peripheral immune system, is an important pathologic mechanism across a range of neurologic diseases. For decades, research focused almost exclusively on how neuroinflammation impacted neuronal function; however, there is accumulating evidence that injury to the oligodendrocyte lineage is an important component for both pathologic and clinical outcomes. While oligodendrocytes are able to undergo an endogenous repair process known as remyelination, this process becomes inefficient and usually fails in the presence of sustained inflammation. The present review focuses on our current knowledge regarding activation of the innate and adaptive immune systems in the chronic demyelinating disease, multiple sclerosis, and provides evidence that sustained neuroinflammation in other neurologic conditions, such as perinatal white matter injury, traumatic brain injury, and viral infections, converges on oligodendrocyte injury. Lastly, the therapeutic potential of targeting the impact of inflammation on the oligodendrocyte lineage in these diseases is discussed.
A subpopulation of astrocytes expressing WD Repeat Domain 49 (WDR49) was recently identified in frontotemporal lobar degeneration (FTLD) with GRN pathogenic variants. This is the first study to investigate their expression and relation to pathology in other FTLD subtypes and Alzheimer's disease (AD). In a postmortem cohort of TDP-43 proteinopathies (12 GRN, 11 C9orf72, 9 sporadic TDP-43), tauopathies (13 MAPT, 8 sporadic tau), 10 AD, and four controls, immunohistochemistry and immunofluorescence were performed for WDR49 and pathological inclusions on frontal, temporal, and occipital cortical sections. WDR49-positive cell counts (adjusted per mm2) were examined and related to digitally quantified percentage areas of TDP-43/tau pathology and semiquantitative scores of neurodegeneration. Quantitative colocalization analysis of WDR49 and pathological inclusions was done. WDR49-positive astrocytes were present across FTLD subtypes and AD in the brain parenchyma and (peri-)vascular space, with distinct morphological patterns, and were particularly enriched in gray matter. In controls, sporadic WDR49-positive cells were found enveloping vessels. WDR49-positive astrocytes were most abundant in the frontal cortex (FC) of GRN cases and temporal cortex in GRN, AD, and sporadic primary tauopathy. In the occipital cortex, only a few cells were found across groups. WDR49-positive astrocyte counts positively correlated with the severity of neurodegeneration and TDP-43 pathology but not tauopathy. Furthermore, in frontotemporal cortices, WDR49 partly colocalized with TDP-43 (14%-21%) and tau (31%-45%). In conclusion, WDR49 is a marker for a subset of astrocytes with different morphologies across FTLD and AD, reflecting the severity of neurodegeneration. These astrocytes may become activated in neurodegeneration in response to pathological damage and migrate from the vessel wall to the parenchyma.
Lipids are small molecule immunomodulators that play critical roles in maintaining cellular health and function. Microglia, the resident immune cells of the central nervous system, regulate lipid metabolism both in the extracellular environment and within intracellular compartments through various mechanisms. For instance, glycerophospholipids and fatty acids interact with protein receptors on the microglial surface, such as the Triggering Receptor Expressed on Myeloid Cells 2, influencing cellular functions like phagocytosis and migration. Moreover, cholesterol is essential not only for microglial survival but, along with other lipids such as fatty acids, is crucial for the formation, function, and accumulation of lipid droplets, which modulate microglial activity in inflammatory diseases. Other lipids, including acylcarnitines and ceramides, participate in various signaling pathways within microglia. Despite the complexity of the microglial lipidome, only a few studies have investigated the effects of specific lipid classes on microglial biology. In this review, we focus on major lipid classes and their roles in modulating microglial function. We also discuss novel analytical techniques for characterizing the microglial lipidome and highlight gaps in current knowledge, suggesting new directions for future research on microglial lipid biology.
B cell-directed CAR T cell therapy has fundamentally changed the treatment of haematological malignancies,and its scope of application is rapidly expanding to include other diseases such as solid tumours or autoimmune disorders.Therapy-refractoriness remains an important challenge in various inflammatory and non-inflammatory disorders of the CNS.The reasons for therapy failure are diverse and include the limited access current therapies have to the CNS,as well as enormous inter-and intra-individual disease heterogeneity.The tissue-penetrating properties of CAR T cells make them a promising option for overcoming this problem and tackling pathologies directly within the CNS.First application of B cell-directed CAR T cells in neuromyelitis optica spectrum disorder and multiple sclerosis patients has recently revealed promising outcomes,expanding the potential of CAR T cell therapy to encompass CNS diseases.Additionally,the optimization of CAR T cells for the therapy of gliomas is a growing field.As a further prospect,preclinical data reveal the potential benefits of CAR T cell therapy in the treatment of primary neurodegenerative diseases such as Alzheimer's disease.Considering the biotechnological optimizations in the field of T cell engineering,such as extension to target different antigens or variation of the modified T cell subtype,new and promising fields of CAR T cell application are rapidly opening up.These innovations offer the potential to address the complex pathophysiological properties of CNS diseases.To use CAR T cell therapy optimally to treat CNS diseases in the future while minimizing therapy risks,further mechanistic research and prospective controlled trials are needed to assess seriously the disease and patient-specific risk-benefit ratio.
The integration of bioinformatics analysis into intracerebral hemorrhage (ICH)research represents a paradigm shift in our approach to understanding, diagnosing, and treating this complex neurological disorder. By leveraging the power of bioinformatics, the scientific community is poised to make significant strides in combating this devastating condition, ultimately improving patient outcomes and quality of life. This study provides a comprehensive overview of the application of bioinformatics tools and techniques in elucidating the genetic, molecular, and environmental underpinnings of ICH. Through a detailed examination of genomic sequencing, transcriptomics, proteomics, and machine learning, we explore how these bioinformatics approaches have contributed to identifying genetic variants, understanding molecular pathways, and discovering biomarkers related to ICH. Challenges such as data complexity, integration of multi-omics data, and the translation of bioinformatics findings into clinical practice are discussed, alongside ethical considerations surrounding data privacy and patient consent. This study underscores the critical role of bioinformatics in advancing our understanding of ICH, offering insights into its pathophysiology, and paving the way for personalized medicine and targeted therapeutic interventions.
Objective:To systematically evaluate the impact of repeated transcranial magnetic stimulation(rTMS)on the rehabilitation outcomes of patients with spinal cord injury(SCI).Methods:Computerized searches were conducted in electronic databases including PubMed,Web of Science,Embase,Cochrane Library,CNKI,Wanfang,VIP,and China Biology Medicine for randomized controlled trials(RCTs)on rTMS treatment for SCI.The search period covered from the inception of each database to September 21,2023.Outcome indicators included the Spinal Cord Independence Measure(SCIM),Functional Independence Measure(FIM),Barthel Index(BI),Resting Motor Threshold(RMT),Motor Evoked Potential(MEP)amplitude,Lower Extremity Motor Score(LEMS),Walking Index for Spinal Cord Injury Ⅱ(WISCI-Ⅱ),Modified Ashworth Scale(MAS),and Visual Analog Scale(VAS)for pain.Risk of bias was assessed using tools recommended by the Cochrane Handbook for Systematic Reviews of Interventions,and Meta-analysis was performed using RevMan 5.4 software.Results:A total of 23 RCTs involving 1 478 patients were enrolled.Meta-analysis results showed significant improvements in the rTMS treatment group compared to the control group in SCIM score[MD=6.93,95％CI(5.48,8.37),P＜0.00001],FIM[MD=16.17,95％CI(11.66,20.69),P＜0.00001],BI score[MD=10.43,95％CI(5.17,15.69),P＜0.00001],RMT[MD=-3.99,95％CI(-4.88,-3.09),P＜0.00001],MEP amplitude[MD=0.33,95％CI(0.23,0.43),P＜0.00001],LEMS[MD=5.47,95％CI(3.80,7.14),P＜0.00001],WISCI-Ⅱ[MD=1.79,95％CI(1.41,2.18),P＜0.00001],MAS score[MD=-0.15,95％CI(-0.20,-0.10),P＜0.0000l],and VAS pain score[MD=-1.37,95％CI(-1.66,-1.08),P＜0.00001].Conclusion:rTMS treatment is beneficial for SCI patients in improving functional independence and activities of daily living,ameliorating lower extremity motor dysfunction,and alleviating neuropathic pain and spasms.
Efficient clearance of hematomas is crucial for improving clinical outcomes in patients with intracerebral hemorrhage(ICH).The glymphatic system,facilitated by aquaporin-4(AQP4),plays a crucial role in cerebrospinal fluid(CSF)entry and metabolic waste clearance.This study examined the role of the glymphatic system in ICH pa-thology,with a focus on AQP4.Collagenase-induced ICH models were established,with AQP4 expression regulated through mifepristone as an agonist,TGN-020 as an inhibitor,and Aqp4 gene knockout.Fluorescence tracing and multimodal magnetic resonance imaging(MRI)were employed to observe glymphatic system functionality,hemato-ma,and edema volumes.Neurological deficit scoring was performed using the modified Garcia Scale.AQP4 expres-sion was quantified using RT-qPCR and Western blotting,and cellular localization was explored using immunofluo-rescence.The brain tissue sections were examined for neuronal morphology,degenerative changes,and iron deposi-tion.Three days post-ICH,the AQP4 agonist group showed increased AQP4 protein expression and perivascular po-larization,decreased hemoglobin levels,and reduced iron deposition.Conversely,the inhibition group exhibited con-trasting trends.AQP4 activation improved glymphatic system function,leading to a wider distribution,improved neurological function,and reduced hematoma.Pharmacological inhibition and genetic knockout of AQP4 have op-posing effects.The glymphatic system,facilitated by AQP4,plays a crucial role in hematoma clearance following ce-rebral hemorrhage.Upregulation of AQP4 improves glymphatic system function,facilitates hematoma clearance,and promotes brain tissue recovery.
The medial prefrontal cortex (mPFC) is involved in cognitive functions such as working memory. Astrocytic cannabinoid type 1 receptor (CB1R) induces cytosolic calcium (Ca2+) concentration changes with an impact on neuronal function. mPFC astrocytes also express adenosine A1 and A2A receptors (A1R, A2AR), being unknown the crosstalk between CB1R and adenosine receptors in these cells. We show here that a further level of regulation of astrocyte Ca2+ signaling occurs through CB1R-A2AR or CB1R-A1R heteromers that ultimately impact mPFC synaptic plasticity. CB1R-mediated Ca2+ transients increased and decreased when A1R and A2AR were activated, respectively, unveiling adenosine receptors as modulators of astrocytic CB1R. CB1R activation leads to an enhancement of long-term potentiation (LTP) in the mPFC, under the control of A1R but not of A2AR. Notably, in IP3R2KO mice, that do not show astrocytic Ca2+ level elevations, CB1R activation decreases LTP, which is not modified by A1R or A2AR. The present work suggests that CB1R has a homeostatic role on mPFC LTP, under the control of A1R, probably due to physical crosstalk between these receptors in astrocytes that ultimately alters CB1R Ca2+ signaling.
