IFI204 in microglia mediates traumatic brain injury-induced mitochondrial dysfunction and pyroptosis via SENP7 interaction

BackgroundRadiation-induced brain injury (RIBI) is a common and severe complication during radiotherapy for head and neck tumor. Repetitive transcranial magnetic stimulation (rTMS) is a novel and non-invasive method of brain stimulation, which has been applied in various neurological diseases. rTMS has been proved to be effective for treatment of RIBI, while its mechanisms have not been well understood.MethodsRIBI mouse model was established by cranial irradiation, K252a was daily injected intraperitoneally to block BDNF pathway. Immunofluorescence staining, immunohistochemistry and western blotting were performed to examine the microglial pyroptosis and hippocampal neurogenesis. Behavioral tests were used to assess the cognitive function and emotionality of mice. Golgi staining was applied to observe the structure of dendritic spine in hippocampus.ResultsrTMS significantly promoted hippocampal neurogenesis and mitigated neuroinflammation, with ameliorating pyroptosis in microglia, as well as downregulation of the protein expression level of NLRP3 inflammasome and key pyroptosis factor Gasdermin D (GSDMD). BDNF signaling pathway might be involved in it. After blocking BDNF pathway by K252a, a specific BDNF pathway inhibitor, the neuroprotective effect of rTMS was markedly reversed. Evaluated by behavioral tests, the cognitive dysfunction and anxiety-like behavior were found aggravated with the comparison of mice in rTMS intervention group. Moreover, the level of hippocampal neurogenesis was found to be attenuated, the pyroptosis of microglia as well as the levels of GSDMD, NLRP3 inflammasome and IL-1β were upregulated.ConclusionOur study indicated that rTMS notably ameliorated RIBI-induced cognitive disorders, by mitigating pyroptosis in microglia and promoting hippocampal neurogenesis via mediating BDNF pathway.

Background Spinal cord ischemia-reperfusion injury (SCII) is a severe neurological condition marked by neuronal damage and functional impairments. The contribution of microglial pyroptosis, an inflammatory form of cell death, to SCII's development is increasingly acknowledged. Yet, the complex molecular mechanisms and potential therapeutic strategies targeting microglial pyroptosis in SCII are not fully understood. Methods Our research utilized both in vivo and in vitro models to evaluate the influence of TREM2 modulation on microglial pyroptosis and neuronal function in SCII. Principal methods included Tarlov scoring, Western blot analysis, Chromatin Immunoprecipitation (CHIP) and histological techniques, with an emphasis on proteins such as Forkhead Box O1 (FOXO1) and pyroptosis-related proteins to decipher the underlying mechanisms. Molecular docking was employed to investigate the interaction between the small molecule diosmetin and TREM2. Results We observed a marked increase in TREM2 expression following SCII, and demonstrated that TREM2 overexpression mitigated microglial pyroptosis and enhanced motor neuron functionality. Further investigation revealed that TREM2 engagement leads to the activation of Forkhead Box O1 (FOXO1) phosphorylation through the Phosphatidylinositol 3-Kinase (PI3K)/Protein Kinase B (AKT) signaling pathway. This activation sequence culminates in the downregulation of Gasdermin D (GSDMD), the primary effector of pyroptosis. Additionally, we identified diosmetin, a natural compound known for its anti-inflammatory and antioxidant effects, as a potent modulator of TREM2-mediated microglial pyroptosis. Experimental data demonstrate diosmetin's binding affinity to TREM2, conferring neuroprotection by impeding microglial pyroptosis through the TREM2/PI3K/AKT/FOXO1/GSDMD axis. Conclusion Our findings underscore the pivotal role of TREM2 in microglial pyroptosis and its therapeutic potential in SCII, positioning diosmetin as a viable pharmacological candidate for SCII prevention and therapy.

Dihydroartemisinin alleviates sepsis-associated encephalopathy by reducing microglial iron accumulation and mitochondrial dysfunction via HIF1A/HMOX1 pathway.

ABSTRACTThis study aims to identify the active components and molecular mechanisms of Ermiao San (EMS) in the treatment of osteoarthritis (OA) through network pharmacology, molecular docking, and molecular dynamics simulations. EMS compounds and their targets were retrieved from TCMSP; OA‐related targets were collected from five public databases. Potential drug‐disease target interactions were analyzed using STRING 12.0 and Cytoscape 3.10.2. Functional and pathway enrichment analyses were performed on the 90 overlapping targets. Molecular docking was performed with CB‐Dock2 and LigPlot+ v2.2.8 platforms, followed by a comprehensive evaluation of key compounds via SwissADME. We identified 46 active chemicals, 187 EMS‐specific targets, and 1718 OA‐related targets, with 90 overlapping targets. Molecular docking and molecular dynamics simulations analysis revealed a strong binding potential of key EMS compounds to target proteins. These findings suggest that EMS exerts its anti‐OA effects through multicomponent, multi‐target, and multipathway interactions.

AimTo explore, using network pharmacology and RNA-seq technologies, potential active targets and mechanisms underpinning Radix Bupleuri’s effectiveness during sepsis treatment.MethodsFollowing the Sepsis-3.0 criteria, the research cohort, comprising 23 sepsis patients and 10 healthy participants, was obtained from public databases. Peripheral blood samples were collected and subjected to RNA-seq analysis. Active ingredients and potential targets of Radix Bupleuri were identified using the Bioinformatics Analysis Tool for Molecular mechANism of Traditional Chinese Medicine 2.0 (BATMAN-TCM 2.0) database and TCMSP database. Subsequently, protein-protein interaction (PPI) network construction, Gene Ontology (GO) analysis, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were conducted to explore cross-targets between disease and drugs. Survival analysis of key targets was performed using the GSE65682 dataset, and single-cell RNA-seq was employed for cellular localization analysis of key genes. Finally, molecular docking and Molecular dynamics simulation of the core target was conducted.ResultsDifferential expression analysis revealed 4253 genes associated with sepsis. Seventy-six active components and 1030 potential targets of Radix Bupleuri were identified. PPI, GO, and pathway enrichment analyses indicated involvement in the regulation of transmembrane transport, monatomic ion transport, and MAPK signaling. Survival curve analysis identified PIK3CD, ARRB2, SUCLG1, and SPI1 as key targets associated with lower mortality in the high expression group, while higher mortality was observed in the high PNP and FURIN expression groups. Single-cell RNA sequencing unveiled the cellular localization of PIK3CD, PNP, SPI1, and FURIN within macrophages, while ARRB2 and SUCLG1 exhibited localization in both macrophages and T-cells. Subsequent molecular docking and Molecular dynamics simulation indicated a potential binding interaction for Carvone-PIK3CD, Encecalin-ARRB2, Lauric Acid-SUCLG1, Pulegone-FURIN, Nootkatone-SPI1, and Saikogenin F-PNP.ConclusionRadix Bupleuri could modulate immune function by affecting PIK3CD, ARRB2, SUCLG1, FURIN, SPI1, and PNP, thereby potentially improving the prognosis of sepsis.

Neuroprotection in spinal cord ischemia-reperfusion injury: Diosmetin's role via TREM2-mediated microglial pyroptosis.

Xiaoqinglong Decoction (XQLD) is a traditional Chinese medicinal formula commonly used to treat chronic urticaria (CU). However, its underlying therapeutic mechanisms remain incompletely characterized. This study employed an integrated approach combining network pharmacology, bioinformatics, molecular docking, and molecular dynamics simulations to identify the active components, potential targets, and related signaling pathways involved in XQLD's therapeutic action against CU, thereby providing a mechanistic foundation for its clinical application. The active components of XQLD and their corresponding targets were identified using the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database. CU-related targets were retrieved from the OMIM and GeneCards databases. Subsequently, core components and targets were determined via protein-protein interaction (PPI) network analysis and component-target-pathway network construction. Topological analyses were performed using Cytoscape software to prioritize core nodes within these networks. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted via the DAVID database to identify enriched biological processes and signaling pathways. Molecular docking was performed to evaluate binding interactions between key components and core targets, while molecular dynamics (MD) simulations were employed to assess the stability of the component-target complexes with the lowest binding energy. Finally, CU-related targets of XQLD were validated using datasets from the Gene Expression Omnibus (GEO) database. A total of 135 active components and 249 potential targets of XQLD were identified, alongside 1,711 CU-related targets. Core components, such as quercetin, kaempferol, beta-sitosterol, naringenin, stigmasterol, and luteolin, exhibited high degree values in the constructed networks. The core targets identified included AKT1, TNF, IL6, TP53, PTGS2, CASP3, BCL2, ESR1, PPARG, and MAPK3. GO and KEGG pathway enrichment analyses revealed the PI3K-Akt signaling pathway as a central regulatory mechanism. Molecular docking studies demonstrated strong binding affinities between active components and core targets, with the stigmasterol-AKT1 complex exhibiting the lowest binding energy (-11.4 kcal/mol) and high stability in MD simulations. Validation using GEO datasets identified 12 core genes shared between CU-related targets and XQLD-associated targets, including PTGS2 and IL6, which were also prioritized as core targets in the network pharmacology analyses. This study comprehensively integrates multidisciplinary approaches to clarify the potential molecular mechanisms of XQLD in treating CU, highlighting its multitarget and multipathway synergistic effects. Molecular docking and dynamics simulations confirm the stable interaction between stigmasterol and the core target AKT1. Additionally, GEO dataset analysis verifies the pathogenic relevance of targets such as PTGS2 and IL6, significantly enhancing the credibility of our findings. These results provide a modern scientific basis for the traditional therapeutic effects of XQLD on CU and have important implications for developing multitarget treatments for this condition. However, this study mainly relies on database mining and computational simulations. Further in vitro and in vivo experimental validations are needed to confirm the predicted component-target-pathway interactions. This study identifies the active components, potential targets, and pathways through which XQLD exerts therapeutic effects on CU. These findings provide a theoretical foundation for further mechanistic studies and support their clinical application in the treatment of CU.

TREM-1, a pro-inflammatory factor, aggravates neuroinflammation following intracerebral hemorrhage (ICH). Both pyroptosis and mitochondrial dysfunction play a vital role in the further injury of ICH. However, whether TREM-1 regulates microglial pyroptosis and mitochondrial fission, and the potential mechanisms underlying these processes, remains unclear. A mouse model of ICH was established via stereotactic injection of collagenase VII-S. To knock down TREM-1 invivo, AAV9-Iba1-TREM-1 was injected into the right basal ganglia. Additionally, the TREM-1-specific inhibitor LP17 was administered intranasally. Neurological function was assessed using behavioral assessments. Invitro, BV2 was stimulated with hemin to mimic ICH. LP17, NLRP3 inhibitor MCC950, TREM-1 agonist antibody Mab1187, and phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 were used to investigate the mechanisms underlying TREM-1-mediated microglial pyroptosis and mitochondrial fission. Immunofluorescence staining, Western blot, RT-qPCR, and transmission electron microscopy were employed to evaluate microglial pyroptosis and mitochondrial fission. Both pharmacological inhibition and AAV-mediated knockdown of TREM-1 significantly improved neurological function, attenuated microglial pyroptosis and mitochondrial fission in ICH mice. TREM-1 was shown to drive microglial pyroptosis through the NLRP3 inflammasome. Furthermore, the PI3K/AKT signaling pathway was demonstrated to regulate TREM-1-induced microglial pyroptosis and mitochondrial fission. This study provides the first evidence that TREM-1 promotes microglial pyroptosis and mitochondrial fission following ICH via the PI3K/AKT signaling pathway. These findings highlight TREM-1 as a potential therapeutic target for mitigating neuroinflammation and neuronal damage in ICH.

Inflammation plays a key role in driving the secondary brain injury that follows ischemic stroke. Melatonin is an endogenous neuroendocrine hormone that regulates mitochondrial homeostasis. However, the role and mechanisms by which melatonin regulates microglial pyroptosis and the inflammatory cascade through double-stranded DNA (dsDNA)-sensing cyclic GMP-AMP synthase (cGAS) signaling warrant further study. Using middle cerebral artery occlusion mice, we investigated the effects of melatonin on cGAS-mediated pyroptosis and neuroinflammation. Middle cerebral artery occlusion model mice exhibited significantly increased DNA damage and cytoplasmic dsDNA release, as reflected by γH2AX staining, as well as heightened activation of the cytosolic dsDNA-sensing cGASSTING pathway, both of which were notably suppressed by melatonin treatment. Melatonin also mitigated NOD-like receptor family, pyrin domain-containing protein 3 (NLRP3) inflammasome activation and nuclear factor (NF)-κB/gasdermin D-mediated pyroptosis in microglia following ischemic stroke, while exhibiting the capacity to attenuate the immune response to ischemia in mice. This led to reduced infiltration of peripheral neutrophils and monocytes/macrophages in the ischemic brain. Specifically, melatonin administration resulted in reductions in the numbers of ionized calcium-binding adapter molecule 1-positive cells and production of interleukin-6 and tumor necrosis factor-α by microglia. Regarding neurological outcomes, melatonin significantly reduced cerebral infarct volume and ameliorated neurological deficits in mice. Notably, the neuroprotective effect of melatonin was correlated with the inhibition of cGAS activity. We also developed and tested melatonin co-loaded macrophage membrane-biomimetic reactive oxygen species-responsive nanoparticles (Mϕ-MLT@FNGs), which exhibited therapeutic properties in middle cerebral artery occlusion mice. Our findings suggest that melatonin acts on microglial pyroptosis to inhibit neuroinflammation and reshape the immune microenvironment through regulation of the cGAS-STING-NF-κB signaling pathway. By doing so, melatonin rescues damaged brain tissue and protects neurological function, highlighting its potential as a neuroprotective treatment for ischemic stroke.

While the α7 nicotinic acetylcholine receptor (α7 nAChR) is implicated in sepsis-associated encephalopathy (SAE), its pathophysiological contributions require further investigation. SAE was induced in mice via cecal ligation and puncture (CLP), and microglia were treated with lipopolysaccharide (LPS). PHA-543613 (an α7 nAChR agonist) was used to activate α7 nAChR. To study the role of α7 nAChR in mitophagy and pyroptosis, caspase-1-deficient mice and PTEN-induced kinase 1 (PINK1) small interfering RNA (siRNA) were used. Cognitive function, cerebral oxygen extraction ratio (CERO2), and brain tissue oxygen pressure (PbtO2) were measured. Blood-brain barrier (BBB) integrity was evaluated via Evan's blue staining. Mitophagy, pyroptosis, and cytokine levels were analyzed via Western blotting and immunofluorescence. CLP or LPS treatment significantly down-regulated α7 nAChR protein expression in microglia. The administration of PHA-543613 to activate α7 nAChR not only restored its expression post-sepsis, but also notably decreased BBB permeability and mitigated cognitive deficits. Both α7 nAChR activation and caspase-1 knockout effectively suppressed microglial pyroptosis. The activation of α7 nAChR also promoted mitophagy in microglia. This led to an amelioration of brain tissue hypoxia, as shown by elevated PbtO2 and reduced CERO2 levels. The suppression of microglial pyroptosis by α7 nAChR was counteracted when mitophagy was inhibited through the siRNA-mediated silencing of PINK1. The activation of α7 nAChR reduces pyroptosis by enhancing microglial mitophagy, thereby mitigating SAE.

Methane-rich saline protects against sepsis-associated cognitive deficits in mice

Qianyang yuyin granule ameliorates mitochondrial dysfunction of hypertensive myocardial remodeling

Molecular mechanism of Yi-Qi-Yang-Yin-Ye against obesity in rats using network pharmacology, molecular docking, and molecular dynamics simulations

A novel brain-derived peptide inhibits microglial pyroptosis through MBTPS1 in neonatal hypoxic-ischemic brain damage.

IntroductionLiver dysfunction contributes to Alzheimer’s disease (AD) pathogenesis, and evidence suggests that the liver is involved in amyloid β (Aβ) clearance, and regulates Aβ deposition in the brain. However, the specific regulatory mechanism remains elusive.ObjectivesAngiopoietin-like protein 8 (ANGPTL8), a high expression of liver-specific secreted proinflammatory factor, crosses the blood‒brain barrier from the bloodstream to abnormally activate microglia and promote AD progression.MethodsThe ANGPTL8−/− mice and 5 × FAD mice were crossed mutated and subjected to the Morris water maze test and novel object recognition test to assess cognitive ability in different cohorts. Thioflavin-S, NeuN, and Nissl staining were used to assess Aβ deposition and neuron loss. The number of phagocytic microglia was evaluated with Fitc latex beads. Adeno-associated virus 8 (AAV8) hydrodynamically injected restored the liver ANGPTL8 levels of ANGPTL8−/− 5 × FAD mice for further experiments. Single-cell RNA sequencing, bulk RNA sequencing and transmission electron microscopy were used to explore the role of ANGPTL8 in regulating AD progression, and drug screening was carried out to identify an effective inhibitor of ANGPTL8.ResultsANGPTL8 knockout improved cognitive function and reduced Aβ deposition by reducing microgliosis and microglial activation in 5xFAD mice. Mechanistically, ANGPTL8 crossed the blood‒brain barrier and interacted with the microglial membrane receptor PirB/LILRB2. This interaction subsequently activated the downstream NLRP3 inflammasome, leading to microglial pyroptosis and exacerbating the Aβ-induced release of inflammatory factors, thereby accelerating AD progression. Furthermore, the administration of metformin, an ANGPTL8 inhibitor, improved learning and memory deficits in 5 × FAD mice by negating microglial pyroptosis and neuroinflammation.ConclusionsANGPTL8 aggravates microglial pyroptosis via the PirB/NLRP3 pathway to accelerate the pathogenesis of AD. Targeting high expression of ANGPTL8 in the liver may hold potential for developing therapies for AD.