Phthalide derivative CD21 attenuates tissue plasminogen activator-induced hemorrhagic transformation in ischemic stroke by enhancing macrophage scavenger receptor 1-mediated DAMP (peroxiredoxin 1) clearance

ALPK1 signaling pathway activation by HMGB1 drives microglial pyroptosis and ferroptosis and brain injury after acute ischemic stroke

Pyroptosis and ferroptosis emerge as remarkable contributors to neuronal death and inflammation following ischemic stroke. High mobility group box 1 (HMGB1), a principal damage-associated molecular pattern (DAMP), is implicated in pyroptosis and ferroptosis post-stroke. Our previous research has demonstrated that alpha kinase 1 (ALPK1), a novel cytoplasmic pattern recognition receptor (PRR), plays an important role in mediating inflammatory damage following ischemic stroke. However, the interaction between ALPK1 and HMGB1, and their combined impact on pyroptosis and ferroptosis post-ischemic stroke remain unexplored, which is what this study aims to investigate. Initially, we observed that ALPK1 ablation attenuated ischemic brain injury of transient middle cerebral artery occlusion (tMCAO) mice. Moreover, recombinant HMGB1 (rHMGB1) stimulation induced the greatest upregulation of ALPK1 expression in microglia compared to astrocytes and neurons. Further investigation using co-immunofluorescence, co-immunoprecipitation, pull-down assay, and molecular docking revealed an interaction between HMGB1 and ALPK1. Additionally, the exacerbation of ischemic brain injury and the induction of microglial pyroptosis and ferroptosis by rHMGB1 treatment in tMCAO mice were significantly mitigated through ALPK1 deficiency by inhibiting the NLRP3/Caspase-1/GSDMD and JAK2/STAT3 signaling pathways. The inhibitory effects of ALPK1 deficiency on pyroptosis and ferroptosis induced by rHMGB1 in microglial cells were further substantiated. Finally, glycyrrhizic acid (GA), an inhibitor of HMGB1, exhibited significant neuroprotective effects in both tMCAO mice and BV2 cells subjected to oxygen-glucose deprivation/reperfusion (OGD/R) by downregulating ALPK1 expression and inhibiting microglial pyroptosis and ferroptosis. Collectively, these findings suggest that HMGB1 may interact with ALPK1 to drive microglial pyroptosis and ferroptosis via the activation of the ALPK1/NF-κB/NLRP3/GSDMD and JAK2/STAT3 signaling pathways, thereby exacerbating brain injury following acute ischemic stroke.

Alpha protein kinase 1 knockout mitigates microglial pyroptosis and cognition deficits in ADP-heptose-stimulated mice

Microglial activation and pyroptosis are central to neuroinflammation and significantly contribute to cognitive decline associated with neurodegenerative diseases. Alpha protein kinase 1 (ALPK1) is recently identified as a critical mediator of inflammatory responses in response to ADP-heptose (a pathogen-associated molecular pattern). However, its specific role in microglial pyroptosis and cognitive dysfunction remains unclear. In this study, we investigated the effects of ALPK1 on cognitive function and pyroptosis in wild-type (WT) and ALPK1 KO mice by intracerebroventricular administration of ADP-heptose to induce neuroinflammation. Cognitive performance was evaluated using behavioral tests (the Y-Maze, Morris Water Maze, and step-down passive avoidance), while Western blot, immunofluorescence, transmission electron microscopy, and enzyme-linked immunosorbent assay were used to evaluate the expression of pyroptosis markers such as NLRP3, Caspase-1, and gasdermin D (GSDMD) in vivo and in vitro. Our results reveal that the absence of ALPK1 significantly attenuated ADP-heptose-induced cognitive deficits and neuronal injury, and inhibited the NLRP3/Caspase-1/GSDMD pathway of pyroptosis and the secretion of pro-inflammatory cytokines IL-1β and IL-18. Notably, ADP-heptose-stimulated conditioned media from primary microglial cells of ALPK1 KO mice significantly enhanced neuronal cell viability, suggesting a protective role for ALPK1 deficiency in supporting neuronal health. These findings suggest the pivotal role of ALPK1 in ADP-heptose-induced microglial pyroptosis and cognitive impairment, thereby highlighting its potential as a therapeutic target in neuroinflammatory disorders.

Z-Ligustilide: A Potential Therapeutic Agent for Atherosclerosis Complicating Cerebrovascular Disease

Atherosclerosis (AS) is one of the major catalysts of ischemic cerebrovascular disease, and the death and disease burden from AS and its cerebrovascular complications are increasing. Z-ligustilide (Z-LIG) is a key active ingredient in Angelica sinensis (Oliv.) Diels and Ligusticum chuanxiong Hort. In this paper, we first introduced LIG's physicochemical properties and pharmacokinetics. Then, we reviewed Z-LIG's intervention and therapeutic mechanisms on AS and its cerebrovascular complications. The mechanisms of Z-LIG intervention in AS include improving lipid metabolism, antioxidant and anti-inflammatory effects, protecting vascular endothelium, and inhibiting vascular endothelial fibrosis, pathological thickening, and plaque calcification. In ischemic cerebrovascular diseases complicated by AS, Z-LIG exerts practical neuroprotective effects in ischemic stroke (IS), transient ischemic attack (TIA), and vascular dementia (VaD) through anti-neuroinflammatory, anti-oxidation, anti-neuronal apoptosis, protection of the blood-brain barrier, promotion of mitochondrial division and angiogenesis, improvement of cholinergic activity, inhibition of astrocyte proliferation, and endoplasmic reticulum stress. This paper aims to provide a basis for subsequent studies of Z-LIG in the prevention and treatment of AS and its cerebrovascular complications and, thus, to promote the development of interventional drugs for AS.

Multi-targeted olink proteomics analyses of cerebrospinal fluid from patients with aneurysmal subarachnoid hemorrhage

BACKGROUND

The complexity of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH) may require the simultaneous analysis of variant types of protein biomarkers to describe it more accurately. In this study, we analyzed for the first time the alterations of cerebrospinal fluid (CSF) proteins in patients with aSAH by multi-targeted Olink proteomics, aiming to reveal the pathophysiology of DCI and provide insights into the diagnosis and treatment of aSAH.

METHODS

Six aSAH patients and six control patients were selected, and CSF samples were analyzed by Olink Proteomics (including 96-neurology panel and 96-inflammation panel) based on Proximity Extension Assay (PEA). Differentially expressed proteins (DEPs) were acquired and bioinformatics analysis was performed.

RESULTS

PCA analysis revealed better intra- and inter-group reproducibility of CSF samples in the control and aSAH groups. 23 neurology-related and 31 inflammation-relevant differential proteins were identified. In the neurology panel, compared to controls, the up-regulated proteins in the CSF of SAH patients predominantly included macrophage scavenger receptor 1 (MSR1), siglec-1, siglec-9, cathepsin C (CTSC), cathepsin S (CTSS), etc. Meanwhile, in the inflammation group, the incremental proteins mainly contained interleukin-6 (IL-6), MCP-1, CXCL10, CXCL-9, TRAIL, etc. Cluster analysis exhibited significant differences in differential proteins between the two groups. GO function enrichment analysis hinted that the differential proteins pertinent to neurology in the CSF of SAH patients were mainly involved in the regulation of defense response, vesicle-mediated transport and regulation of immune response; while the differential proteins related to inflammation were largely connected with the cellular response to chemokine, response to chemokine and chemokine-mediated signaling pathway. Additionally, in the neurology panel, KEGG enrichment analysis indicated that the differential proteins were significantly enriched in the phagosome, apoptosis and microRNAs in cancer pathway. And in the inflammation panel, the differential proteins were mainly enriched in the chemokine signaling pathway, viral protein interaction with cytokine and cytokine receptor and toll-like receptor signaling pathway.

CONCLUSIONS

These identified differential proteins reveal unique pathophysiological characteristics secondary to aSAH. Further characterization of these proteins and aberrant pathways in future research could enable their application as potential therapeutic targets and biomarkers for DCI after aSAH.

Targeting NETosis in Acute Brain Injury: A Systematic Review of Preclinical and Clinical Evidence

Acute brain injury (ABI) remains one of the leading causes of death and disability world-wide. Its treatment is challenging due to the heterogeneity of the mechanisms involved and the variability among individuals. This systematic review aims at evaluating the impact of anti-histone treatments on outcomes in ABI patients and experimental animals and defining the trend of nucleosome levels in biological samples post injury. We performed a search in Pubmed/Medline and Embase databases for randomized controlled trials and cohort studies involving humans or experimental settings with various causes of ABI. We formulated the search using the PICO method, considering ABI patients or animal models as population (P), comparing pharmacological and non-pharmacological therapy targeting the nucleosome as Intervention (I) to standard of care or no treatment as Control (C). The outcome (O) was mortality or functional outcome in experimental animals and patients affected by ABI undergoing anti-NET treatments. We identified 28 studies from 1246 articles, of which 7 were experimental studies and 21 were human clinical studies. Among these studies, only four assessed the effect of anti-NET therapy on circulating markers. Three of them were preclinical and reported better outcome in the interventional arm compared to the control arm. All the studies observed a significant reduction in circulating NET-derived products. NETosis could be a target for new treatments. Monitoring NET markers in blood and cerebrospinal fluid might predict mortality and long-term outcomes. However, longitudinal studies and randomized controlled trials are warranted to fully evaluate their potential, as current evidence is limited.

Sepsis-induced inflammatory demyelination in medullary visceral zone and cholinergic anti-inflammatory pathway: Insights from a Rat's model study

Background

Our previous studies have demonstrated that the activated Cholinergic Anti-inflammatory Pathway (CAP) effectively suppresses systemic inflammation and immunity in early sepsis. Some parameters of Heart Rate Variability (HRV) could be used to reflect the regulatory activity of CAP. However, in the early stages of severe sepsis of some patients, the inflammatory storm can still result in multiple organs dysfunction and even death, suggesting they lose CAP's modulation ability. Since CAP is part of the vagus nerve and is directly innervated by the Medullary Visceral Zone (MVZ), we can reasonably concluded that pathological changes induced by MVZ's neuroinflammation should be responsible for CAP's dysfunction in modulating systemic inflammation in early sepsis.

Methods

We conducted two independent septic experiments, the sepsis model rats were prepared by cecum ligation and puncture (CLP) method. In the first experiment, A total of 64 adult male Sprague-Dawley rats were included. Under the condition of sepsis and CAP's pharmacological activation or blockade, we investigated the MVZ's pathological changes, the functional state of key neurons including catecholaminergic and cholinergic neurons, key genes' expression such as Oligodendrocyte Transcription Factor 2 (Olig-2) mRNA, glial fibrillary acidic protein (GFAP) mRNA, and matrix metalloprotein (MMP) -9 mRNA, and CAP's activities reflected by HRV. The second experiment involved in 56 rats, through central anti-inflammation by feeding with 10 mg/ml minocycline sucrose solution as the only water source, or right vagus transection excepting for central anti-inflammation as a mean of the CAP's functional cancel, we confirmed that the neuroinflammation in MVZ affected systemic inflammation through CAP in sepsis.

Results

In the first experiment, cholinergic and catecholaminergic neurons showed significant apoptosis with reduced expressions of TH, but the expression of CHAT remained relatively unaffected in MVZ in sepsis. HRV parameters representing the tone of the vagus nerve, such as SDNN, RMSSD, HF, SD1, and SD2, did not show significant differences among the three Septic Groups, although they all decreased significantly compared to the Control Group. The expressions of GFAP mRNA and MMP-9 mRNA were up-regulated, while the expression of Olig-2 mRNA was down-regulated in the Septic Groups. Intervention of CAP had a significant effect on cholinergic and catecholaminergic neurons' apoptosis, as well as the expressions of TH/CHAT and these key genes, but had little effect on HRV in sepsis. In the second experiment, the levels of TNF-α, IL-6, in serum and MVZ were significantly increased in sepsis. Central anti-inflammatory treatment reversed these changes. However, right vagotomy abolished the central anti-inflammatory effect.

Conclusions

Our study uncovered that MVZ's neuroinflammation may play a crucial role in the uncontrolled systemic inflammation through inflammatory demyelination in MVZ, which disrupts CAP's modulation on the systemic inflammation in early sepsis.

FDA compound library screening Baicalin upregulates TREM2 for the treatment of cerebral ischemia-reperfusion injury

Acute ischemic stroke (AIS) is a leading cause of global incidence and mortality rates. Oxidative stress and inflammation are key factors in the pathogenesis of AIS neuroinjury. Therefore, it is necessary to develop drugs that target neuroinflammation and oxidative stress in AIS. The Triggering Receptor Expressed on Myeloid Cells 2 (TREM2), primarily expressed on microglial cell membranes, plays a critical role in reducing inflammation and oxidative stress in AIS. In this study, we employed a high-throughput screening (HTS) strategy to evaluate 2625 compounds from the (Food and Drug Administration) FDA library in vitro to identify compounds that upregulate the TREM2 receptor on microglia. Through this screening, we identified Baicalin as a potential drug for AIS treatment. Baicalin, a flavonoid compound extracted and isolated from the root of Scutellaria baicalensis, demonstrated promising results. Next, we established an in vivo mouse model of cerebral ischemia-reperfusion injury (MCAO/R) and an in vitro microglia cell of oxygen-glucose deprivation reperfusion (OGD/R) to investigate the role of Baicalin in inflammation injury, oxidative stress, and neuronal apoptosis. Our results showed that baicalin effectively inhibited microglia activation, reactive oxygen species (ROS) production, and inflammatory responses in vitro. Additionally, baicalin suppressed neuronal cell apoptosis. In the in vivo experiments, baicalin not only improved neurological functional deficits and reduced infarct volume but also inhibited microglia activation and inflammatory responses. Overall, our findings demonstrate the efficacy of Baicalin in treating MCAO/R by upregulating TREM2 to reduce inflammatory responses and inhibit neuronal apoptosis.

Engineered inhaled nanocatalytic therapy for ischemic cerebrovascular disease by inducing autophagy of abnormal mitochondria

Mitochondrial dysfunction and subsequent accumulation of reactive oxygen species (ROS) are key contributors to the pathology of ischemic cerebrovascular disease. Therefore, elimination of ROS and damaged mitochondria is crucial for the effective treatment of this disease. For this purpose, we designed an inhalation nanotherapeutic agent, P/D@Mn/Co3O4, to treat ischemic cerebrovascular disease. Mn/Co3O4 effectively removed excess ROS from cells, reduced acute cellular oxidative stress, and protected neural cells from apoptosis. Furthermore, it depleted the H+ surrounding mitochondria and depolarized the mitochondrial membrane potential, inducing mitophagy and eliminating abnormal mitochondria, thereby avoiding the continuous overproduction of ROS by eliminating the source of ROS regeneration. On intranasal administration, Mn/Co3O4 encapsulated by platelet membranes and 2,3-(dioxy propyl)-trimethylammonium chloride can bypass the blood-brain barrier, enter the brain through the trigeminal and olfactory pathways, and target inflammatory regions to remove ROS and damaged mitochondria from the lesion area. In rat models of stroke and vascular dementia, P/D@Mn/Co3O4 effectively inhibited the symptoms of acute and chronic cerebral ischemia by scavenging ROS and damaged mitochondria in the affected area. Our findings indicate that the nanotherapeutic agent developed in this study can be used for the effective treatment of ischemic cerebrovascular disease.

Immunomodulatory role of estrogen in ischemic stroke: neuroinflammation and effect of sex

Although estrogen is predominantly related to the maintenance of reproductive functioning in females, it mediates various physiological effects in nearly all tissues, especially the central nervous system. Clinical trials have revealed that estrogen, especially 17β-estradiol, can attenuate cerebral damage caused by an ischemic stroke. One mechanism underlying this effect of 17β-estradiol is by modulating the responses of immune cells, indicating its utility as a novel therapeutic strategy for ischemic stroke. The present review summarizes the effect of sex on ischemic stroke progression, the role of estrogen as an immunomodulator in immune reactions, and the potential clinical value of estrogen replacement therapy. The data presented here will help better understand the immunomodulatory function of estrogen and may provide a basis for its novel therapeutic use in ischemic stroke.

Zhilong Huoxue Tongyu Capsule attenuates hemorrhagic transformation through the let-7f/TLR4 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Hemorrhagic transformation after acute ischemic stroke is a life-threatening disease that currently has no effective chemotherapy. Zhilong Huoxue Tongyu Capsule (ZL) is an empirical prescription of traditional Chinese medicine that is used to prevent and treat cardiovascular and cerebrovascular diseases in China. However, only a few studies have addressed the mechanisms of ZL in treating hemorrhagic transformation.

AIM OF THE STUDY

To evaluate the anti-inflammatory effects of ZL on hemorrhagic transformation model rats and lipopolysaccharide (LPS)-induced RAW264.7 macrophages and to explore the underlying molecular mechanisms.

MATERIALS AND METHODS

Murine RAW264.7 cells were treated with ZL and LPS (1 μg/mL), and cell viability was detected by cell counting kit-8 assay. RT-qPCR was used to detect the expression of inflammatory chemokines, microRNA let-7a/e/i/f, toll like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), and nuclear factor kappa-B (NF-κB) p65. The protein expression levels of TLR4, MyD88, NF-κB p65, and apoptosis related molecules were determined by Western blotting. The apoptosis rate of RAW264.7 macrophages was detected by Annexin V-FITC/PI double staining. A hemorrhagic transformation model in rats was established by intraperitoneal injection of high glucose solution combined with thread embolization. Then, the model rats were observed behaviourally, pathologically, and molecularly. The gene expression of TLR4, MyD88, and NF-κB p65 was measured by RT-qPCR and used to evaluate the protective effect of ZL against hemorrhagic transformation in rats.

RESULTS

ZL (5, 20, 40 μg/mL) was beneficial in cell proliferation. LPS (1 μg/mL) stimulated the production of inflammatory chemokines and inhibited the production of let-7a/e/i/f, with let-7f being influenced most strongly. Moreover, overexpression of let-7f decreased the gene and protein levels of TLR4, MyD88, and NF-κB p65, downregulated TLR4, and inhibited its transcriptional activity. ZL (5, 20, and 40 μg·mL-1) inhibited the production of TLR4, MyD88, and NF-κB p65 and promoted the production of let-7f in a concentration-dependent manner. Furthermore, the blockade of TLR4 antagonized the promoting effects of TLR4 pathway activation in cell inflammation and apoptosis by downregulating let-7f. Critically, it was confirmed in vivo and in vitro that ZL upregulated the expression of let-7f and inhibited the gene expression of TLR4, MyD88, and NF-κB p65 to reduce inflammatory cell infiltration, which determined the occurrence of hemorrhagic transformation.

CONCLUSIONS

ZL can reduce inflammatory response by upregulating let-7f and subsequently inhibiting the TLR4 signaling pathway, thereby decreasing the occurrence of hemorrhagic transformation.

COVID-19-induced neurological symptoms: focus on the role of metal ions

Neurological symptoms are prevalent in both the acute and post-acute phases of coronavirus disease 2019 (COVID-19), and they are becoming a major concern for the prognosis of COVID-19 patients. Accumulation evidence has suggested that metal ion disorders occur in the central nervous system (CNS) of COVID-19 patients. Metal ions participate in the development, metabolism, redox and neurotransmitter transmission in the CNS and are tightly regulated by metal ion channels. COVID-19 infection causes neurological metal disorders and metal ion channels abnormal switching, subsequently resulting in neuroinflammation, oxidative stress, excitotoxicity, neuronal cell death, and eventually eliciting a series of COVID-19-induced neurological symptoms. Therefore, metal homeostasis-related signaling pathways are emerging as promising therapeutic targets for mitigating COVID-19-induced neurological symptoms. This review provides a summary for the latest advances in research related to the physiological and pathophysiological functions of metal ions and metal ion channels, as well as their role in COVID-19-induced neurological symptoms. In addition, currently available modulators of metal ions and their channels are also discussed. Collectively, the current work offers a few recommendations according to published reports and in-depth reflections to ameliorate COVID-19-induced neurological symptoms. Further studies need to focus on the crosstalk and interactions between different metal ions and their channels. Simultaneous pharmacological intervention of two or more metal signaling pathway disorders may provide clinical advantages in treating COVID-19-induced neurological symptoms.

Predictive Value of CT Perfusion in Hemorrhagic Transformation after Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

Background: Existing studies indicate that some computed tomography perfusion (CTP) parameters may predict hemorrhagic transformation (HT) after acute ischemic stroke (AIS), but there is an inconsistency in the conclusions alongside a lack of comprehensive comparison. Objective: To comprehensively evaluate the predictive value of CTP parameters in HT after AIS. Data sources: A systematical literature review of existing studies was conducted up to 1st October 2022 in six mainstream databases that included original data on the CTP parameters of HT and non-HT groups or on the diagnostic performance of relative cerebral blood flow (rCBF), relative permeability-surface area product (rPS), or relative cerebral blood volume (rCBV) in patients with AIS that completed CTP within 24 h of onset. Data Synthesis: Eighteen observational studies were included. HT and non-HT groups had statistically significant differences in CBF, CBV, PS, rCBF, rCBV, and rPS (p < 0.05 for all). The hierarchical summary receiver operating characteristic (HSROC) revealed that rCBF (area under the curve (AUC) = 0.9), rPS (AUC = 0.89), and rCBV (AUC = 0.85) had moderate diagnostic performances in predicting HT. The pooled sensitivity and specificity of rCBF were 0.85 (95% CI, 0.75−0.91) and 0.83 (95% CI, 0.63−0.94), respectively. Conclusions: rCBF, rPS, and rCBV had moderate diagnostic performances in predicting HT, and rCBF had the best pooled sensitivity and specificity.

Phthalide derivative CD21 regulates the platelet- neutrophil extracellular trap-thrombin axis and protects against ischemic brain injury in rodents

Prothrombotic and proinflammatory properties of neutrophil extracellular traps (NETs) contribute to brain damage after ischemic stroke. CD21 is a novel phthalide neuroprotectant against cerebral ischemia in rodents. This study investigated effects of CD21 on the platelet-NET-thrombin axis and ischemic brain injury and the underlying mechanism. CD21 exerteddose-dependent neuroprotectionin rats that were subjected to2 h middle cerebral artery occlusion,dose-dependentlyinhibited adenosine diphosphate-mediatedplatelet aggregationin rats, and dose-dependentlyexertedanti-thrombotic activityin rodents that received a collagen-epinephrine combination, ferric chloride, or an arteriovenous shunt. Equimolar CD21 doses exerted stronger efficacy than 3-N-butylphthalide (NBP, natural phthalide for the treatment of ischemic stroke). CD21 dose-dependently improved regional cerebral blood flow, neurobehavioral deficits, and infarct volume in mice that were subjected to photothrombotic stroke (PTS). CD21 (13.79 mg/kg, i.v.) significantly decreased NET components (plasma dsDNA concentrations; mRNA levels of elastase, myeloperoxidase, and neutrophil gelatinase-associated lipocalin and protein level of citrullinated histone H3 in ischemic brain tissues), mRNA and protein levels of peptidyl-arginine deiminase 4 (PDA4, NET formation enzyme), and mRNA levels of NET-related inflammatory mediators (interleukin-1β, interleukin-17A, matrix metalloproteinase 8, and matrix metalloproteinase 9) in ischemic brain tissues, despite no effect on mRNA levels of deoxyribonuclease I (NET elimination enzyme). Pretreatment with compound C (inhibitor of adenosine monophosphate-activated protein kinase [AMPK]) significantly reversed the inhibitory effects of CD21 on NETs, PDA4, and inflammatory mediators in PTS mice. These results suggest that CD21 might regulate the platelet-NET-thrombin axis and protect against ischemic brain injury partly through the induction of AMPK activation.

Recent advances in natural phthalides: Distribution, chemistry, and biological activities

Phthalides, an important class of bioactive natural products, are widely distributed in plants, fungi, lichens, and liverworts. Amon them, n-butylphthalide, a phthalide monomer, has been approved to cure ischemic stroke. Owing to their good bioactivities in anti-microbial, anti-inflammatory, anti-tumor, anti-diabetic, and other aspects, a large number of researches have been conducted on phthalides from nature materials. In recent years, hundreds of novel natural phthalides were obtained. This review provides profiles of the advances in the distribution, chemistry, and biological activities of natural phthalides in 2016-2022.

Efferocytosis in the Central Nervous System

The effective clearance of apoptotic cells is essential for maintaining central nervous system (CNS) homeostasis and restoring homeostasis after injury. In most cases of physiological apoptotic cell death, efferocytosis prevents inflammation and other pathological conditions. When apoptotic cells are not effectively cleared, destruction of the integrity of the apoptotic cell membrane integrity, leakage of intracellular contents, and secondary necrosis may occur. Efferocytosis is the mechanism by which efferocytes quickly remove apoptotic cells from tissues before they undergo secondary necrosis. Cells with efferocytosis functions, mainly microglia, help to eliminate apoptotic cells from the CNS. Here, we discuss the impacts of efferocytosis on homeostasis, the mechanism of efferocytosis, the associations of efferocytosis failure and CNS diseases, and the current clinical applications of efferocytosis. We also identify efferocytosis as a novel potential target for exploring the causes and treatments of CNS diseases.