Interactions between brain-resident and peripheral infiltrated immune cells are thought to contribute to neuroplasticity after cerebral ischemia. However, conventional bulk sequencing makes it challenging to depict this complex immune network. Using single-cell RNA sequencing, we mapped compositional and transcriptional features of peri-infarct immune cells. Microglia were the predominant cell type in the peri-infarct region, displaying a more diverse activation pattern than the typical pro- and anti-inflammatory state, with axon tract-associated microglia (ATMs) being associated with neuronal regeneration. Trajectory inference suggested that infiltrated monocyte-derived macrophages (MDMs) exhibited a gradual fate trajectory transition to activated MDMs. Inter-cellular crosstalk between MDMs and microglia orchestrated anti-inflammatory and repair-promoting microglia phenotypes and promoted post-stroke neurogenesis, with SOX2 and related Akt/CREB signaling as the underlying mechanisms. This description of the brain's immune landscape and its relationship with neurogenesis provides new insight into promoting neural repair by regulating neuroinflammatory responses.
Humans ; Ischemic Stroke ; Brain/metabolism* ; Macrophages ; Brain Ischemia/metabolism* ; Microglia/metabolism* ; Gene Expression Profiling ; Anti-Inflammatory Agents ; Neuronal Plasticity/physiology* ; Infarction/metabolism*

OBJECTIVE: To summarize the research progress on the role of macrophage-mediated osteoimmune in osteonecrosis of the femoral head (ONFH) and its mechanisms. METHODS: Recent studies on the role and mechanism of macrophage-mediated osteoimmune in ONFH at home and abroad were extensively reviewed. The classification and function of macrophages were summarized, the osteoimmune regulation of macrophages on chronic inflammation in ONFH was summarized, and the pathophysiological mechanism of osteonecrosis was expounded from the perspective of osteoimmune, which provided new ideas for the treatment of ONFH. RESULTS: Macrophages are important immune cells involved in inflammatory response, which can differentiate into classically activated type (M1) and alternatively activated type (M2), and play specific functions to participate in and regulate the physiological and pathological processes of the body. Studies have shown that bone immune imbalance mediated by macrophages can cause local chronic inflammation and lead to the occurrence and development of ONFH. Therefore, regulating macrophage polarization is a potential ONFH treatment strategy. In chronic inflammatory microenvironment, inhibiting macrophage polarization to M1 can promote local inflammatory dissipation and effectively delay the progression of ONFH; regulating macrophage polarization to M2 can build a local osteoimmune microenvironment conducive to bone repair, which is helpful to necrotic tissue regeneration and repair to a certain extent. CONCLUSION At present, it has been confirmed that macrophage-mediated chronic inflammatory immune microenvironment is an important mechanism for the occurrence and development of ONFH. It is necessary to study the subtypes of immune cells in ONFH, the interaction between immune cells and macrophages, and the interaction between various immune cells and macrophages, which is beneficial to the development of potential therapeutic methods for ONFH.
Humans ; Femur Head/pathology* ; Osteonecrosis/therapy* ; Macrophages/pathology* ; Inflammation ; Femur Head Necrosis/pathology*

Objective To investigate the effect of interleukin-6 (IL-6) on the phagocytosis of MH-S alveolar macrophages and its related mechanisms. Methods A mouse acute lung injury (ALI) model was constructed by instilling lipopolysaccharide (LPS) into the airway. ELISA was used to detect the content of IL-6 in bronchoalveolar lavage fluid (BALF). In vitro cultured MH-S cells, in the presence or absence of signal transducer and activator 3 of transcription(STAT3) inhibitor Stattic (5 μmol/L), IL-6 (10 ng/mL~500 ng/mL) was added to stimulate for 6 hours, and then incubated with fluorescent microspheres for 2 hours. The phagocytosis of MH-S cells was detected by flow cytometry. Western blot analysis was used to detect the expression levels of phosphorylated Janus kinase 2 (p-JAK2), phosphorylated STAT3 (p-STAT3), actin-related protein 2 (Arp2) and filamentous actin (F-actin). Results The content of IL-6 in BALF was significantly increased after the mice were injected with LPS through the airway. With the increase of IL-6 stimulation concentration, the phagocytic function of MH-S cells was enhanced, and the expression levels of Arp2 and F-actin proteins in MH-S cells were increased. The expression levels of p-JAK2 and p-STAT3 proteins increased in MH-S cells stimulated with IL-6(100 ng/mL). After blocking STAT3 signaling, the effect of IL-6 in promoting phagocytosis of MH-S cells disappeared completely, and the increased expression of Arp2 and F-actin proteins in MH-S cells induced by IL-6 was also inhibited. Conclusion IL-6 promotes the expression of Arp2 and F-actin proteins by activating the JAK2/STAT3 signaling pathway, thereby enhancing the phagocytic function of MH-S cells.
Animals ; Mice ; Actins ; Disease Models, Animal ; Interleukin-6 ; Janus Kinase 2 ; Lipopolysaccharides ; Macrophages, Alveolar ; Signal Transduction

Humans ; Animals ; Mice ; NF-kappa B/metabolism* ; Crohn Disease/drug therapy* ; Dextran Sulfate ; Colitis/metabolism* ; Macrophages/metabolism* ; Adenosine Triphosphate/metabolism* ; Mice, Inbred C57BL ; Disease Models, Animal ; Colon/metabolism*

Humans ; Tumor-Associated Macrophages/pathology* ; Neuroblastoma/pathology*

Humans ; Trained Immunity ; Atherosclerosis ; Macrophages

Objective: To investigate the effect of microRNA (miR-148b) targeting decoy receptor 3 (DcR3) on macrophage polarization in sepsis. Methods: Experimental study. From December 2019 to December 2022, serum microRNA expression was detected in 3 patients with sepsis and 3 healthy controls in the clinical laboratory of Songjiang Hospital Affiliated to Shanghai Jiao Tong University School of Medicine. Phorbol 12-myristate 13-acetate (PMA) was used to induce the differentiation of human acute monocytic leukemia cells THP-1 into macrophages, and then lipopolysaccharide (LPS) was added to stimulate the establishment of a sepsis cell model, and the expression changes of miR-148b and DcR3 were detected by RT-PCR and Western blot. Overexpression of DcR3 was used to detect the expression levels of TNF-α, CD163 and IL-10 in macrophages stimulated by LPS (100 ng/ml). Overexpression of miR-148b was used to observe the changes of molecular markers of macrophage polarization. The targeting regulation effect of miR-148b on DcR3 was determined by dual-luciferase reporter assay. t test was used to analyze whether there were statistical differences among the groups. Results: The expression of miR-148b was down-regulated (P<0.05) and the expression of DcR3 was up-regulated (P<0.01) in THP-1 macrophages stimulated by LPS. Overexpression of DcR3 inhibited the expression of TNF-α (P<0.05) and promoted the expression of CD163 (P<0.01) and IL-10 (P<0.01). When miR-148b mimics was added, the opposite effect was observed. The dual-luciferase reporter assay confirmed that miR-148b targets and binds to DcR3, inhibiting its transcription and expression. The results of flow cytometry showed that DcR3 could reverse the promoting effect of miR-148b on the CD86/CD163 ratio of macrophages (P<0.05). Conclusion: miR-148b inhibits the expression of DcR3, thereby inhibiting M2 polarization in LPS-stimulated macrophage cells.
Humans ; Interleukin-10 ; Lipopolysaccharides/pharmacology* ; Macrophages ; MicroRNAs/genetics* ; Receptors, Tumor Necrosis Factor, Member 6b/metabolism* ; Tumor Necrosis Factor-alpha

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal interstitial lung disease, the cause is not yet clear. Pathological manifestations are abnormal repair changes resulting from sustained lung injury. Macrophages have been identified as playing a key role in IPF pathogenesis. In different local microenvironments, macrophages can exhibit either classically activated (M1) or alternately activated (M2) phenotypes. M1 plays a key role in promoting inflammatory response and is involved in the process of causing alveolar tissue injury. M2 is involved in wound healing and stopping lung inflammation. Previous studies have shown that activation of 5-hydroxytryptamine (5-HT) signaling is enhanced in pulmonary fibrosis and that 5-HT receptors play an important role in the observed pro-fibrotic effects. As a multifunctional signaling molecule, 5-HT is closely related to lung macrophage polarization, early lung tissue injury, abnormal proliferation and repair, and late extracellular matrix (ECM) deposition. This article reviewed the role of 5-HT and M2 macrophages in the pathogenesis of IPF and the possible regulatory mechanism of 5-HT, in order to provide a reference for further research.
Humans ; Serotonin ; Macrophages ; Lung Diseases, Interstitial/pathology* ; Lung/pathology* ; Idiopathic Pulmonary Fibrosis ; Fibrosis

Humans ; Nitric Oxide ; Carcinoma, Non-Small-Cell Lung/drug therapy* ; Lung Neoplasms ; Lung ; Nitric Oxide Synthase ; Macrophages, Alveolar ; Pulmonary Alveoli

Cancer is a major threat to human health and causes death worldwide. Research on the role of radiotherapy (RT) in the treatment of cancer is progressing; however, RT not only causes fatal DNA damage to tumor cells, but also affects the interactions between tumor cells and different components of the tumor microenvironment (TME), including immune cells, fibroblasts, macrophages, extracellular matrix, and some soluble products. Some cancer cells can survive radiation and have shown strong resistance to radiation through interaction with the TME. Currently, the complex relationships between the tumor cells and cellular components that play major roles in various TMEs are poorly understood. This review explores the relationship between RT and cell-cell communication in the TME from the perspective of immunity and hypoxia and aims to identify new RT biomarkers and treatment methods in lung cancer to improve the current status of unstable RT effect and provide a theoretical basis for further lung cancer RT sensitization research in the future.
Humans ; Neoplasms/pathology* ; Lung Neoplasms/complications* ; Fibroblasts/pathology* ; Biomarkers ; Macrophages/pathology* ; Hypoxia ; Tumor Microenvironment