Microglial functions are linked to Ca²⁺ signaling, with endoplasmic reticulum (ER) calcium stores playing a crucial role. Microglial abnormality is a hallmark of Alzheimer's disease (AD), but how ER Ca²⁺ receptors regulate microglial functions under physiological and AD conditions remains unclear. We found reduced ryanodine receptor 2 (Ryr2) expression in microglia from an AD mouse model. Modulation of RyR2 using S107, a RyR-Calstabin stabilizer, blunted spontaneous Ca²⁺ transients in controls and normalized Ca²⁺ transients in AD mice. S107 enhanced ATP-induced migration and phagocytosis while reducing ramification in control microglia; however, these effects were absent in AD microglia. Our findings indicate that RyR2 stabilization promotes an activation state shift in control microglia, a mechanism impaired in AD. These results highlight the role of ER Ca²⁺ receptors in both homeostatic and AD microglia, providing insights into microglial Ca²⁺ malfunctions in AD.
Animals ; Microglia/pathology* ; Alzheimer Disease/pathology* ; Phagocytosis/drug effects* ; Ryanodine Receptor Calcium Release Channel/metabolism* ; Disease Models, Animal ; Mice ; Cell Movement/drug effects* ; Mice, Transgenic ; Calcium Signaling/physiology* ; Calcium/metabolism* ; Mice, Inbred C57BL ; Male ; Endoplasmic Reticulum/metabolism*

Triggering receptor expressed on myeloid cells 2 (TREM2)-mediated microglial phagocytosis is an energy-intensive process that plays a crucial role in amyloid beta (Aβ) clearance in Alzheimer's disease (AD). Energy metabolic reprogramming (EMR) in microglia induced by TREM2 presents therapeutic targets for cognitive impairment in AD. Jiawei Xionggui Decoction (JWXG) has demonstrated effectiveness in enhancing energy supply, protecting microglia, and mitigating cognitive impairment in APP/PS1 mice. However, the mechanism by which JWXG enhances Aβ phagocytosis through TREM2-mediated EMR in microglia remains unclear. This study investigates how JWXG facilitates microglial phagocytosis and alleviates cognitive deficits in AD through TREM2-mediated EMR. Microglial phagocytosis was evaluated through immunofluorescence staining in vitro and in vivo. The EMR level of microglia was assessed using high-performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA) kits. The TREM2/protein kinase B (Akt)/mammalian target of rapamycin (mTOR)/hypoxia-inducible factor-1α (HIF-1α) signaling pathway was analyzed using Western blotting in BV₂ cells. TREM2^-/- BV₂ cells were utilized for reverse validation experiments. The Aβ burden, neuropathological features, and cognitive ability in APP/PS1 mice were evaluated using ELISA kits, immunohistochemistry (IHC), and the Morris water maze (MWM) test. JWXG enhanced both the phagocytosis of EMR disorder-BV₂ cells (EMRD-BV₂) and increased EMR levels. Notably, these effects were significantly reversed in TREM2^-/- BV₂ cells. JWXG elevated TREM2 expression, adenosine triphosphate (ATP) levels, and microglial phagocytosis in APP/PS1 mice. Additionally, JWXG reduced Aβ-burden, neuropathological lesions, and cognitive deficits in APP/PS1 mice. In conclusion, JWXG promoted TREM2-induced EMR and enhanced microglial phagocytosis, thereby reducing Aβ deposition, improving neuropathological lesions, and alleviating cognitive deficits.
Drugs, Chinese Herbal/pharmacology* ; Microglia/drug effects* ; Phagocytosis ; Cognitive Dysfunction/drug therapy* ; Metabolic Reprogramming ; Animals ; Mice ; Cell Line ; Receptors, Immunologic/metabolism* ; Membrane Glycoproteins/metabolism* ; Signal Transduction ; Amyloid beta-Peptides/metabolism* ; Energy Metabolism

To develop a method for determining the antibody-dependent cell-mediated phagocytosis (ADCP) activity of human epidermal growth factor receptor 2 (HER2)-targeted antibody drug conjugate (ADC) based on the reporter gene assay, we established an ADCP activity assay with Jurkat/NFAT/FcγRIIa cells as the effector cells and BT474 as the target cells. Then, the target cell density, the ratio of effector to target cells, the target cell adhesion time, the incubation time for drug administration, and the induction time after adding effector cells were optimized by the method of design of experiment (DOE). The method showed a significant dose-response relationship, which was complied with the four-parameter equation: y=(A-D)/[1+(x/C)^B]+D. The durability ranges of the target cell density, the ratio of effector to target cells, the target cell adhesion time, the incubation time for drug administration, and the induction time after adding effector cells were (2.5-4.0)×10⁵ cells/mL, 3-5, 1.0-2.0 h, 0 h, and 5.0-6.0 h, respectively. The results of the methodological validation showed that the linear equation was y=1.106 8x-0.011 6, r=0.969 2. The established method showed the relative accuracy ranging from -6.59% to 2.98% and the geometric coefficient of variation less than 11% in the intermediate precision test. Furthermore, the method was target-specific. The method was then applied to the determination of ADCP activity of HER2-targeted ADC, demonstrating the result of (103.5±5.7)%. We developed a reporter gene assay for determining the ADCP activity of HER2-targeted ADC and the assay demonstrated high accuracy and good reproducibility, which proposes a highly efficient and approache for evaluating ADCP effect of this HER2-targeted ADC, and also provides a referable technique for characterizing the Fc effector functions of ADCs with diverse targets.
Humans ; Receptor, ErbB-2/immunology* ; Phagocytosis/drug effects* ; Immunoconjugates/immunology* ; Genes, Reporter ; Antibody-Dependent Cell Cytotoxicity ; Jurkat Cells

The study aimed to investigate the effect of the CD200R1 gene deletion on microglia activation and nigrostriatal dopamine neuron loss in the Parkinson's disease (PD) process. The CRISPR-Cas9 technology was applied to construct the CD200R1^-/- mice. The primary microglia cells of wild-type and CD200R1^-/- mice were cultured and treated with bacterial lipopolysaccharide (LPS). Microglia phagocytosis level was assessed by a fluorescent microsphere phagocytosis assay. PD mouse model was prepared by nigral stereotaxic injection of recombinant adeno-associated virus vector carrying human α-synuclein (α-syn). The changes in the motor behavior of the mice with both genotypes were evaluated by cylinder test, open field test, and rotarod test. Immunohistochemical staining was used to assess the loss of dopamine neurons in substantia nigra. Immunofluorescence staining was used to detect the expression level of CD68 (a key molecule involved in phagocytosis) in microglia. The results showed that CD200R1 deletion markedly enhanced LPS-induced phagocytosis in vitro by the microglial cells. In the mouse model of PD, CD200R1 deletion exacerbated motor behavior impairment and dopamine neuron loss in substantia nigra. Fluorescence intensity analysis results revealed a significant increase in CD68 expression in microglia located in the substantia nigra of CD200R1^-/- mice. The above results suggest that CD200R1 deletion may further activates microglia by promoting microglial phagocytosis, leading to increased loss of the nigrostriatal dopamine neurons in the PD model mice. Therefore, targeting CD200R1 could potentially serve as a novel therapeutic target for the treatment of early-stage PD.
Animals ; Microglia/physiology* ; Mice ; Phagocytosis ; Parkinson Disease/genetics* ; Disease Models, Animal ; Receptors, Cell Surface/physiology* ; Dopaminergic Neurons/pathology* ; Antigens, CD/metabolism* ; Gene Deletion ; Substantia Nigra ; Mice, Inbred C57BL ; Mice, Knockout ; Cells, Cultured ; Male ; alpha-Synuclein ; CD68 Molecule ; Orexin Receptors

This study employed bioinformatics to screen the feature genes related to efferocytosis in diabetic kidney disease(DKD) and explores traditional Chinese medicine(TCM) regulating these feature genes. The GSE96804 and GSE30528 datasets were integrated as the training set, and the intersection of differentially expressed genes and efferocytosis-related genes(ERGs) was identified as DKD-ERGs. Subsequently, correlation analysis, protein-protein interaction(PPI) network construction, enrichment analysis, and immune infiltration analysis were performed. Consensus clustering was conducted on DKD patients based on the expression levels of DKD-ERGs, and the expression levels, immune infiltration characteristics, and gene set variations between different subtypes were explored. Eight machine learning models were constructed and their prediction performance was evaluated. The best-performing model was evaluated by nomograms, calibration curves, and external datasets, followed by the identification of efferocytosis-related feature genes associated with DKD. Finally, potential TCMs that can regulate these feature genes were predicted. The results showed that the training set contained 640 differentially expressed genes, and after intersecting with ERGs, 12 DKD-ERGs were obtained, which demonstrated mutual regulation and immune modulation effects. Consensus clustering divided DKD into two subtypes, C1 and C2. The support vector machine(SVM) model had the best performance, predicting that growth arrest-specific protein 6(GAS6), S100 calcium-binding protein A9(S100A9), C-X3-C motif chemokine ligand 1(CX3CL1), 5'-nucleotidase(NT5E), and interleukin 33(IL33) were the feature genes of DKD. Potential TCMs with therapeutic effects included Astragali Radix, Trionycis Carapax, Sargassum, Rhei Radix et Rhizoma, Curcumae Radix, and Alismatis Rhizoma, which mainly function to clear heat, replenish deficiency, activate blood, resolve stasis, and promote urination and drain dampness. Molecular docking revealed that the key components of these TCMs, including β-sitosterol, quercetin, and sitosterol, exhibited good binding activity with the five target genes. These results indicated that efferocytosis played a crucial role in the development and progression of DKD. The feature genes closely related to both DKD and efferocytosis, such as GAS6, S100A9, CX3CL1, NT5E, and IL33, were identified. TCMs such as Astragali Radix, Trionycis Carapa, Sargassum, Rhei Radix et Rhizoma, Curcumae Radix, and Alismatis Rhizoma may provide a new therapeutic strategy for DKD by regulating efferocytosis.
Humans ; Computational Biology ; Diabetic Nephropathies/physiopathology* ; Protein Interaction Maps ; Medicine, Chinese Traditional ; Drugs, Chinese Herbal ; Phagocytosis/genetics* ; Efferocytosis

Efferocytosis refers to the process of phagocytes engulfing and clearing the cells after programmed cell death. In recent years, an increasing number of studies have shown that the mechanisms of efferocytosis are closely related to drug-induced liver injury, hepatic ischemia-reperfusion injury, viral hepatitis, cholestatic liver diseases, metabolic-associated fatty liver disease, alcoholic liver disease, and other liver disorders. This review summarized the research progress on the role of efferocytosis in liver diseases, with the hope of providing new targets for the prevention and treatment of liver diseases.
Humans ; Liver Diseases/metabolism* ; Animals ; Phagocytosis/physiology* ; Phagocytes ; Efferocytosis

Objective To investigate the effect and mechanism of Efferocytosis Relatived LncRNA (EFRL) on homocysteine-induced atherosclerosis in macrophage efferocytosis. Methods RAW264.7 cells were cultured in vitro, and the Control group (0 μmol/L Hcy) and Hcy intervention group (100 μmol/L Hcy) were set up. After GapmeR transfection of macrophages with Hcy intervention, EFRL knockdown negative control group (Hcy combined with LNA-NC) and EFRL knockdown group (Hcy combined with LNA-EFRL) were set up. High-throughput sequencing was applied for different expression of LncRNA MSTRG. 88917.16 (EFRL), UCSC was used to analyze its conservation, CPC and CPAT were used to analyze its ability to encode proteins, and GO and KEGG were used to analyze related biological functions. The localization of LncRNA EFRL in macrophages was analyzed by nucleoplasmic separation and RNA-FISH. Quantitative real-time PCR was used to detect the expression levels of LncRNA EFRL and its target gene SPAST in Hcy-treated macrophages. The apoptosis rate of Jurkat cells induced by UV was detected by flow cytometry. In vitro efferocytosis assay combined with immunofluorescence technique was used to analyze macrophage efferocytosis. ELISA was used to detect the levels of interleukin 1β(IL-1β) and IL-18. Results The new LncRNA MSTRG.88917.16 was identified and named EFRL(Efferocytosis Relatived LncRNA). UCSC, CPC and CPAT analyses showed that LncEFRL is highly conserved and does not have the ability to encode proteins. GO and KEGG analyses suggested that LncEFRL may be involved in macrophage efferocytosis. LncRNA EFRL was localized in the nucleus of macrophages as determined by nucleoplasmic separation and RNA-FISH. In comparison to the Control group, the expression levels of LncRNA EFRL and its target gene SPAST in the Hcy group were increased. In comparison to the Control group (0 min), the apoptosis rate of the experimental group (15, 30 min) Annexin V is more than 85%. Compared with Hcy combined with LNA-NC group, Hcy combined with LNA-EFRL group had enhanced macrophage efferocytosis and reduced levels of inflammatory factors. Compared with Hcy combined with LNA-NC group, the expression level of SPAST in Hcy combined with LNA-EFRL group was decreased. Conclusion Inhibition of EFRL expression can alleviate the process of Hcy inhibiting macrophage efferocytosis, and the mechanism is related to the regulation of the downstream target gene SPAST by EFRL.
RNA, Long Noncoding/physiology* ; Animals ; Homocysteine ; Mice ; Macrophages/drug effects* ; Humans ; RAW 264.7 Cells ; Atherosclerosis/chemically induced* ; Apoptosis/genetics* ; Phagocytosis/genetics* ; Jurkat Cells ; Interleukin-1beta/genetics* ; Efferocytosis

Invasive fungal infections (IFIs) are a group of diseases caused by fungal pathogens, primarily Candida, Aspergillus, and Cryptococcus, which invade the body, proliferate in deep tissues, organs, or the bloodstream, and lead to localized or systemic severe infections. These infections impose significantclinical and economic burdens due to their high mortality rates, the high cost and limited availability of antifungal drugs, and the frequent adverse effects. Invasive fungal pathogens invade the host through hyphae, spores, and secreted adhesive proteins, primarily triggering disease via signal cascades resulting from the binding of fungal membrane ligands to host receptors, as well as through secreted substances and intrinsic toxins. Macrophages, as the first line of defense against invasive fungal pathogens, play a crucial role in combating IFIs. They combat fungal pathogens through mechanisms such as antigen recognition, phagocytosis, oxidative killing, polarization, and the regulation of various bioactive substances. This article reviews recent research progress on the mechanisms by which macrophages contribute to innate immunity against invasive fungal infections. Additionally, it discusses the immune evasion strategies employed by invasive fungal pathogens to counteract macrophages, aiming to provide new insights for the prevention and treatment of invasive fungal infections.
Humans ; Immunity, Innate ; Macrophages/immunology* ; Invasive Fungal Infections/microbiology* ; Animals ; Phagocytosis/immunology*

Asthma is a chronic inflammatory disease of the airway involving various cellular players. Among the different phenotypes of asthma, neutrophilic asthma is often associated with severe airway inflammation and a notable resistance to corticosteroid treatment. Macrophages, as innate immune cells, play a crucial role in the pathogenesis of neutrophilic asthma. They regulate neutrophil recruitment and activation to promote the progression of airway inflammation. During this process, macrophages also undergo changes in aspects such as efferocytosis. We reviewed the recent research progresses regarding the role of macrophages in the pathogenesis of neutrophilic asthma, aiming to provide valuable insights for future studies in this area.
Humans ; Asthma/pathology* ; Neutrophils/pathology* ; Macrophages/immunology* ; Animals ; Phagocytosis

Neutrophils, as the most abundant immune cells in the human body, possess the inherent ability to rapidly migrate to sites of inflammation and infection. Novel drug delivery systems leveraging neutrophils capitalize on their natural targeting and phagocytic capabilities to achieve precise drug delivery. Efficient drug loading into neutrophils within neutrophil-based delivery systems can be achieved through physical adsorption, chemical conjugation, and phagocytosis. Design strategies emphasize carrier selection and targeting ligand design to enhance delivery precision. Compared to traditional drug delivery systems, neutrophil-based systems offer significant advantages, including excellent biocompatibility and strong tissue penetration. These properties can significantly improve drug bioavailability and reduce adverse reactions associated with non-target tissue accumulation. However, these systems also face several challenges that require resolution, such as difficulties in cell collection and preservation, the need for stability optimization, challenges in large-scale production, and a lengthy clinical translation cycle. In disease treatment applications, neutrophil-based drug delivery systems enable precise delivery of anti-cancer drugs to tumor sites, potentially disrupting immunosuppression of the tumor microenvironment and enhancing therapeutic efficacy. For brain diseases, their unique ability to cross the blood-brain barrier facilitates effective drug delivery. In chronic inflammatory diseases, neutrophil-based systems can precisely deliver anti-inflammatory agents to mitigate inflammation. Performance enhancements for neutrophil-based systems can be achieved by the development of novel nanomaterials and optimization of targeting ligand affinity, thereby improving the accuracy and efficiency of drug delivery. This review comprehensively explores the design strategies, advantages, challenges, and future directions of neutrophil-based drug delivery systems. It summarizes research progress in disease treatment applica-tions, aiming to offer key insights for the development of novel drug delivery systems and advance precision medicine and targeted therapy.
Humans ; Drug Delivery Systems/methods* ; Neutrophils ; Phagocytosis ; Drug Carriers ; Blood-Brain Barrier ; Neoplasms/drug therapy*