BACKGROUND: Lung adenocarcinoma (LUAD) remains one of the leading causes of cancer morbidity and mortality worldwide, and its initiation and progression are closely associated with the tumor immune microenvironment. Increasing evidence suggests that environmental exposure is a critical factor influencing lung cancer development. Among these factors, fine particulate matter (PM2.5), a major component of air pollution, has been strongly linked to elevated lung cancer risk and unfavorable prognosis. However, the underlying immunoregulatory mechanisms by which PM2.5 drives LUAD progression remain poorly understood. Tumor-associated macrophages (TAMs), especially those polarized toward the M2 phenotype, are key components of the tumor microenvironment and play crucial roles in tumor growth, angiogenesis, and immune evasion. This study aims to investigate the effects of PM2.5 exposure on TAMs and to identify the key pro-tumorigenic factors mediating this process. METHODS: A mouse orthotopic lung cancer model under PM2.5 exposure was established to assess lung tumor growth and macrophage phenotypic alterations using in vivo imaging and flow cytometry. A subcutaneous tumor model involving co-inoculated macrophages and tumor cells was used to further verify the effects of PM2.5 on the function of TAMs and tumor malignancy. Combining in vitro experiments, flow cytometry, Western blot, reverse transcription quantitative polymerase chain reaction (RT-qPCR), cell counting kit-8 (CCK-8) assay, colony formation assay, and wound healing assay were employed to evaluate the regulatory effects of PM2.5 on the polarization of bone marrow-derived macrophages (BMDMs) as well as tumor cell proliferation, migration, and colony-forming ability. Transcriptome sequencing integrated with TISIDB (Tumor-immune System Interactions Database) and GEPIA (Gene Expression Profiling Interactive Analysis) databases was performed to identify key cytokines for further functional validation. RESULTS: In the mouse orthotopic lung cancer model, PM2.5 exposure significantly promoted tumor growth and increased the proportion of M2-type TAMs (P<0.05). Subcutaneous co-inoculation with PM2.5-treated BMDMs markedly enhanced tumor proliferation and elevated the intratumoral M2-type TAMs. PM2.5-pretreated BMDMs exhibited an immunosuppressive programmed cell death ligand 1 (PD-L1)+/arginase 1 (Arg1)+ phenotype, and their conditioned media significantly promoted proliferation, migration, and colony formation of Lewis lung carcinoma cells (LLC) and B16 melanoma cells (B16) (P<0.05). Transcriptome analysis revealed that PM2.5 substantially altered macrophage gene expression, with IL-1α identified as a key upregulated secreted cytokine enriched in immunosuppressive related signaling pathways. Clinical database analyses further indicated that IL-1α expression was positively correlated with macrophage and regulatory T cells (Treg) infiltration in the LUAD immune microenvironment, and that high IL-1α expression was associated with worse overall survival in LUAD patients (HR=1.5, P=0.0053). Western blot, RT-qPCR, and immunofluorescence confirmed that PM2.5 exposure significantly upregulated IL-1α expression and secretion in TAMs. CONCLUSIONS PM2.5 exposure facilitates LUAD progression by inducing an immunosuppressive phenotype in macrophages and enhancing the malignant behaviors of tumor cells. Mechanistically, IL-1α may serve as a key pro-tumorigenic cytokine secreted by macrophages under PM2.5 exposure. This study provides new insights into the pathogenesis of PM2.5-associated LUAD and suggests that IL-1α could serve as a potential therapeutic target.
Animals ; Mice ; Tumor-Associated Macrophages/immunology* ; Particulate Matter/toxicity* ; Adenocarcinoma of Lung/metabolism* ; Lung Neoplasms/genetics* ; Humans ; Disease Progression ; Tumor Microenvironment/drug effects* ; Cell Proliferation/drug effects* ; Cell Line, Tumor

OBJECTIVE: To investigate the inhibitory effect of Tanreqing Injection (TRQ) on the activation of nucleotide-binding oligomerization domain-like receptor pyrin domain containing 3 (NLRP3) inflammasome in macrophages infected with influenza A virus and the underlying mechanism based on mitophagy pathway. METHODS: The inflammatory model of murine macrophage J774A.1 induced by influenza A virus [strain A/Puerto Rico/8/1934 (H1N1), PR8] was constructed and treated by TRQ, while the mitochondria-targeted antioxidant Mito-TEMPO and autophagy specific inhibitor 3-methyladenine (3-MA) were used as controls to intensively study the anti-inflammatory mechanism of TRQ based on mitophagy-mitochondrial reactive oxygen species (mtROS)-NLRP3 inflammasome pathway. The levels of NLRP3, Caspase-1 p20, microtubule-associated protein 1 light chain 3 II (LC3II) and P62 proteins were measured by Western blot. The release of interleukin-1β (IL-1β) was tested by enzyme linked immunosorbent assay, the mtROS level was detected by flow cytometry, and the immunofluorescence and co-localization of LC3 and mitochondria were observed under confocal laser scanning microscopy. RESULTS: Similar to the effect of Mito-TEMPO and contrary to the results of 3-MA treatment, TRQ could significantly reduce the expressions of NLRP3, Caspase-1 p20, and autophagy adaptor P62, promote the expression of autophagy marker LC3II, enhance the mitochondrial fluorescence intensity, and inhibit the release of mtROS and IL-1β (all P<0.01). Moreover, LC3 was co-localized with mitochondria, confirming the type of mitophagy. CONCLUSION TRQ could reduce the level of mtROS by promoting mitophagy in macrophages infected with influenza A virus, thus inhibiting the activation of NLRP3 inflammasome and the release of IL-1β, and attenuating the inflammatory response.
Mitophagy/drug effects* ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Animals ; Macrophages/virology* ; Inflammasomes/drug effects* ; Drugs, Chinese Herbal/pharmacology* ; Mice ; Mitochondria/metabolism* ; Reactive Oxygen Species/metabolism* ; Influenza A virus/physiology* ; Interleukin-1beta/metabolism* ; Cell Line ; Injections

OBJECTIVE: To identify the underlying mechanism by which quercetin (Que) alleviates sepsis-related acute respiratory distress syndrome (ARDS). METHODS: In vivo, C57BL/6 mice were assigned to sham, cecal ligation and puncture (CLP), and CLP+Que (50 mg/kg) groups (n=15 per group) by using a random number table. The sepsisrelated ARDS mouse model was established using the CLP method. In vitro, the murine alveolar macrophages (MH-S) cells were classified into control, lipopolysaccharide (LPS), LPS+Que (10 μmol/L), and LPS+Que+acetylcysteine (NAC, 5 mmol/L) groups. The effect of Que on oxidative stress, inflammation, and apoptosis in mice lungs and MH-S cells was determined, and the mechanism with reactive oxygen species (ROS)/p38 mitogen-activated protein kinase (MAPK) pathway was also explored both in vivo and in vitro. RESULTS: Que alleviated lung injury in mice, as reflected by a reversal of pulmonary histopathologic changes as well as a reduction in lung wet/dry weight ratio and neutrophil infiltration (P<0.05 or P<0.01). Additionally, Que improved the survival rate and relieved gas exchange impairment in mice (P<0.01). Que treatment also remarkedly reduced malondialdehyde formation, superoxide dismutase and catalase depletion, and cell apoptosis both in vivo and in vitro (P<0.05 or P<0.01). Moreover, Que treatment diminished the release of inflammatory factors interleukin (IL)-1β, tumor necrosis factor-α, and IL-6 both in vivo and in vitro (P<0.05 or P<0.01). Mechanistic investigation clarifified that Que administration led to a decline in the phosphorylation of p38 MAPK in addition to the suppression of ROS expression (P<0.01). Furthermore, in LPS-induced MH-S cells, ROS inhibitor NAC further inhibited ROS/p38 MAPK pathway, as well as oxidative stress, inflammation, and cell apoptosis on the basis of Que treatment (P<0.05 or P<0.01). CONCLUSION Que was found to exert anti-oxidative, anti-inflammatory, and anti-apoptotic effects by suppressing the ROS/p38 MAPK pathway, thereby conferring protection for mice against sepsis-related ARDS.
Animals ; Sepsis/drug therapy* ; Quercetin/therapeutic use* ; Respiratory Distress Syndrome/enzymology* ; p38 Mitogen-Activated Protein Kinases/metabolism* ; Mice, Inbred C57BL ; Reactive Oxygen Species/metabolism* ; Apoptosis/drug effects* ; Male ; Oxidative Stress/drug effects* ; MAP Kinase Signaling System/drug effects* ; Lung/drug effects* ; Mice ; Lipopolysaccharides ; Macrophages, Alveolar/pathology* ; Inflammation/pathology* ; Protective Agents/therapeutic use*

OBJECTIVES: Sepsis-associated acute lung injury (S-ALI) is one of the major causes of death in intensive care unit (ICU) patients, yet its mechanisms remain incompletely understood and effective therapies are lacking. Lytic cell death of macrophages is a key driver of the inflammatory cascade in S-ALI. PANoptosis, a newly recognized form of lytic cell death characterized by PANoptosome assembly and activation, involves plasma membrane rupture (PMR) mediated by ninjurin-1 (NINJ1), a recently identified pore-forming protein. Itaconic acid is known for its anti-inflammatory effects, but its role in macrophage PANoptosis during S-ALI is unclear. This study aims to investigate the protective effect of itaconic acid on macrophage PANoptosis in S-ALI to provide new therapeutic insights. METHODS: Male specific-pathogen-free C57BL/6J mice (6-8 weeks, 18-20 g) received intraperitoneal lipopolysaccharide (LPS) to establish a classical S-ALI model. Western blotting was used to assess PANoptosome-related proteins and enzymes involved in the itaconic acid metabolic pathway, while real-time reverse transcription polymerase chain reaction and metabolomics quantified itaconic acid levels. Primary peritoneal macrophages (PMs) were pretreated with the itaconate derivative 4-octyl itaconate (4-OI) and then exposed to tumor necrosis factor alpha (TNF-α) plus interferon gamma (IFN-γ) to induce PANoptosis. Cell viability was evaluated by cell counting kit-8 (CCK-8) assay. Western blotting was employed to quantify enzymes of the itaconate-metabolic pathway in PANoptotic macrophages, to evaluate the impact of 4-OI on PANoptosome-associated proteins, and to determine NINJ1 abundance in lung tissues from S-ALI mice and in PANoptotic macrophages. Fluorescent dye FM_4-64 was used to visualize 4-OI-mediated changes in PMR, whereas immunofluorescence staining mapped the effect of 4-OI on both the expression level and membrane localization of NINJ1 in PANoptotic macrophages. The effect of 4-OI on lactate dehydrogenase (LDH) release in culture supernatants and peripheal blood serum was assessed using a LDH assay kit, and non-denataring polyacylamide gel electrophoresis was used to assess the expression of NINJ1 in S-ALI mouse lung tissues and the impact of 4-OI on the expression of PANoptosis-associated NINJ1 multimeric reflected protein in macropahges. RESULTS: In S-ALI mouse lungs, PANoptosome components [NOD-like receptor thermal protein domain associated protein 3 (NLRP3), Gasdermin D (GSDMD), Caspase-1, Z-DNA binding protein (ZBP1), and Caspase-3] and phosphorylated mixed lineage kinase domain-like protein (MLKL) S345 were significantly upregulated (all P<0.05), while metabolomics showed compensatory increases in itaconic acid and its key enzymes [aconitate decarboxylase 1 (ACOD1)/immunoresponsive gene 1 (IRG1)]. In macrophages, 4-OI obviously suppressed PANoptosome protein expression, reduced LDH release, restored plasma membrane integrity, and inhibited NINJ1 expression and oligomerization at the membrane (P<0.05). CONCLUSIONS Itaconic acid may alleviate macrophage PANoptosis in S-ALI by inhibiting NINJ1-mediated plasma membrane rupture. Targeting NINJ1 or enhancing itaconate pathways may offer a novel therapeutic strategy for S-ALI.
Animals ; Acute Lung Injury/pathology* ; Succinates/pharmacology* ; Sepsis/complications* ; Mice, Inbred C57BL ; Male ; Mice ; Macrophages/pathology* ; Cell Membrane/metabolism* ; Lipopolysaccharides ; Hydro-Lyases

Bone is a highly calcified and vascularized tissue. The vascular system plays a vital role in supporting bone growth and repair, such as the provision of nutrients, growth factors, and metabolic waste transfer. Moreover, the additional functions of the bone vasculature, such as the secretion of various factors and the regulation of bone-related signaling pathways, are essential for maintaining bone health. In the bone microenvironment, bone tissue cells play a critical role in regulating angiogenesis, including osteoblasts, bone marrow mesenchymal stem cells (BMSCs), and osteoclasts. Osteogenesis and bone angiogenesis are closely linked. The decrease in osteogenesis and bone angiogenesis caused by aging leads to osteoporosis. Long noncoding RNAs (lncRNAs) are involved in various physiological processes, including osteogenesis and angiogenesis. Recent studies have shown that lncRNAs could mediate the crosstalk between angiogenesis and osteogenesis. However, the mechanism by which lncRNAs regulate angiogenesis‒osteogenesis crosstalk remains unclear. In this review, we describe in detail the ways in which lncRNAs regulate the crosstalk between osteogenesis and angiogenesis to promote bone health, aiming to provide new directions for the study of the mechanism by which lncRNAs regulate bone metabolism.
RNA, Long Noncoding/physiology* ; Osteogenesis/physiology* ; Humans ; Neovascularization, Physiologic/genetics* ; Bone and Bones/metabolism* ; Animals ; Mesenchymal Stem Cells ; Signal Transduction ; Osteoblasts ; Osteoclasts ; Angiogenesis

Macrophages derived from the human THP-1 cell line have been widely used as substitutes for primary macrophages in various macrophage-related studies. However, difficulties still exist in establishing THP-1 macrophage models. This research presents techniques for generating different phenotypes of activated macrophages derived from THP-1 cells by introducing specific stimuli and provides some potential markers to confirm each type of activated macrophage. It is hoped to provide novel and useful methods for scientific research and to help researchers explore this field more intuitively and effectively.
Humans ; Macrophages/physiology* ; THP-1 Cells ; Cell Culture Techniques/methods* ; Macrophage Activation ; Cell Polarity ; Cell Differentiation ; Phenotype ; Cell Line

OBJECTIVES: To investigate the effect of high glucose on macrophage polarization and the role of immune-responsive gene 1 (IRG1) in mediating its effect. METHODS: RAW264.7 cells were transfected with IRG1-overexpressing plasmid or IRG1 siRNA via electroporation and cultured in either normal or high glucose for 72 h to observe the changes in cell viability and morphology using CCK-8 assay and phase contrast microscopy. The protein levels of IRG1, iNOS, Arg-1, IL-1β and IL-10 in the treated cells were detected with Western blotting, and the fluorescence intensities of iNOS and Arg-1 were detected using immunofluorescence assay. The protein levels of IL-1β and IL-10 in the culture medium were determined with ELISA. RESULTS: High glucose exposure significantly reduced IRG1 and Arg-1 expressions, increased iNOS and IL-1β expressions and IL-1β secretion, and decreased IL-10 level in RAW264.7 cells. Transfection with the IRG1-overexpressing plasmid provided the cells with obvious resistance to high glucose-induced changes in iNOS, Arg-1, IL-1β and IL-10, whereas IRG1 knockdown further enhanced the effects of high glucose exposure on Arg-1 expression and the expression and secretion of IL-10. CONCLUSIONS High glucose promotes M1 polarization of the macrophages possibly through a mechanism to inhibit the expression of IRG1 protein, thus leading to chronic inflammatory response.
Animals ; Mice ; Macrophages/drug effects* ; Glucose/pharmacology* ; Interleukin-10/metabolism* ; Nitric Oxide Synthase Type II/metabolism* ; RAW 264.7 Cells ; Interleukin-1beta/metabolism* ; Arginase/metabolism* ; RNA, Small Interfering/genetics* ; Transfection ; Inflammation

OBJECTIVES: To explore the active components that mediate the therapeutic effect of Centella asiatica on psoriasis and their therapeutic mechanisms. METHODS: TCMSP, TCMIP, PharmMapper, Swiss Target Prediction, GeneCards, OMIM and TTD databases were searched for the compounds in Centella asiatica and their targets and the disease targets of psoriasis. A drug-active component-target network and the protein-protein interaction network were constructed, and DAVID database was used for pathway enrichment analysis. In a RAW264.7 macrophage model of LPS-induced inflammation, the anti-inflammatory effect of 7.5, 15, 30, and 60 μmol/L quercetin, asiaticoside, and asiatic acid, which were identified as the main active components in Centella asiatica, were tested by measuring cellular production of NO, TNF‑α and IL-6 using Griess method and ELISA and by detecting mRNA expressions of IL-23, IL-17A, TNF-α and IL-6 and protein expressions of p-STAT3 (Tyr705) and p-STAT3 (Ser727) with RT-qPCR and Western blotting. RESULTS: A total of 139 targets of Centella asiatica and 4604 targets of psoriasis were obtained, and among them CASP3, EGFR, PTGS2, and ESR1 were identified as the core targets. KEGG analysis suggested that quercetin, asiaticoside, and asiatic acid in Centella asiatica were involved in cancer and IL-17 and MAPK signaling pathways. In the RAW264.7 macrophage model of inflammation, treatment with quercetin significantly reduced cellular production of NO, TNF‑α and IL-6, and lowered mRNA expressions of IL-23, IL-17A, TNF‑α and IL-6 and protein expressions of p-STAT3 (Tyr705) and p-STAT3 (Ser727). CONCLUSIONS Quercetin, asiaticoside and asiatic acid are the main active components in Centella asiatica to mediate the therapeutic effect against psoriasis, and quercetin in particular is capable of suppressing cellular production of NO, TNF‑α and IL-6 and regulating the IL-23/IL-17A inflammatory axis by mediating STAT3 phosphorylation to inhibit inflammatory response.
Quercetin/pharmacology* ; Psoriasis/metabolism* ; STAT3 Transcription Factor/metabolism* ; Mice ; Animals ; Centella/chemistry* ; Triterpenes/pharmacology* ; Phosphorylation ; Interleukin-17/metabolism* ; Interleukin-23/metabolism* ; RAW 264.7 Cells ; Pentacyclic Triterpenes/pharmacology* ; Macrophages/drug effects* ; Signal Transduction ; Plant Extracts

OBJECTIVES: To investigate the clinical significance of SLC1A5 overexpression in pan-cancer and its mechanism for promoting hepatocellular carcinoma (HCC) progression. METHODS: We analyzed the correlation of SLC1A5 expression with clinical stage, lymph node metastasis and prognosis in pan-cancer using TCGA and ICGC datasets and explored its association with immune cell infiltration using EPIC, CIBERSORT, and TIMER algorithms. In HCC cell lines, the effects of lentivirus-mediated SLC1A5 overexpression or RNA interference on cell proliferation were examined using CCK-8 assay, and the growth of HCC cell xenografts overexpressing SLC1A5 was observed in nude mice. The effects of SLC1A5 overexpression or silencing in HCC cells on macrophage polarization were evaluated in a cell co-culture system. RESULTS: SLC1A5 was mainly localized on cell membrane and was highly expressed in most cancers in association with clinical stage, lymph node metastasis and poor prognosis. SLC1A5 expression was positively correlated with immunity score in 13 cancer types, especially in low-grade glioma (LGG), LIHC and thyroid cancer. SLC1A5 was positively correlated with macrophage infiltration level in LGG and LIHC but negatively correlated with macrophage infiltration in 5 cancers including lung squamous carcinoma, pancreatic carcinoma, and gastric carcinoma. Patients with SLC1A5 overexpression and high level of M2 macrophage infiltration had the worst survival outcomes. SLC1A5 was correlated with immunosuppression-related genes, cytokines, and cytokine receptors, which was the most obvious in LGG and LIHC. SLC1A5 was highly expressed in different HCC cell lines, and its overexpression promoted HCC cell proliferation both in vitro and in nude mice. In the cell co-culture experiment, SLC1A5 was positively correlated with the molecular markers of M2 polarization of macrophages, and its overexpression strongly promoted M2 polarization of the macrophages and inhibited T cell secretion of IFN-γ. CONCLUSIONS SLC1A5 expression level is correlated with clinical stage, lymph node metastasis, prognosis, and immune cell infiltration in most cancers, and its overexpression promotes HCC progression by inhibiting T-cell function via promoting M2 polarization of macrophages.
Humans ; Carcinoma, Hepatocellular/metabolism* ; Liver Neoplasms/metabolism* ; Animals ; Macrophages/cytology* ; Disease Progression ; Cell Line, Tumor ; Mice ; Amino Acid Transport System ASC/genetics* ; Cell Proliferation ; Lymphatic Metastasis ; Mice, Nude ; Prognosis ; Minor Histocompatibility Antigens

OBJECTIVES: To investigate the core targets and immunomodulatory mechanisms of Huoluo Xiaoling Pellet (HLXLP) for promoting tissue repair. METHODS: Network pharmacology and protein-protein interaction network were used to screen active components in HLXLP, the disease-related targets and the core targets, followed by GO and KEGG enrichment analyses and molecular docking to predict the pharmacological mechanisms. The toxicity of HLXLP was evaluated in zebrafish, and in a tissue regeneration model established in 3 dpf zebrafish larvae by amputating 95% of the tail fin, the effects of a formulated zebrafish embryo culture medium and 10, 20, and 40 μg/mL of aqueous extract of HLXLP on tissue regeneration was evaluated; RT-qPCR was performed to detect mRNA expressions of tissue regeneration marker genes and the core target genes. Transgenic zebrafish with fluorescently labeled macrophages and neutrophils were used to observe immune cell migration during tissue regeneration, and macrophage polarization at different stages was assessed with RT-qPCR. RESULTS: We identified a total of 149 intersected targets between HLXLP active components and tissue repair and 5 core targets (AKT1, IL-6, TNF-α, EGFR and STAT3). GO and KEGG analyses suggested that the effects of HLXLP were mediated primarily through the JAK-STAT pathway, adhesion junctions and positive regulation of cell migration. HLXLP was minimally toxic below 40 μg/mL and lethal at 320 μg/mL in zebrafish, and caused renal and pericardial edema and vascular defects above 80 μg/mL. In zebrafish with tail fin amputation, HLXLP significantly promoted tissue regeneration, reduced IL-6 and TNF-α and enhanced AKT1, EGFR and STAT3 mRNA expressions, modulated neutrophil and macrophage recruitment to the injury sites, and regulated M1/M2 macrophage polarization during tissue regeneration. CONCLUSIONS HLXLP promotes zebrafish tail fin regeneration through multiple active components, targets and pathways for immunomodulation of immune cell migration and macrophage polarization to suppress inflammation and accelerate healing.
Animals ; Zebrafish/physiology* ; Animal Fins/drug effects* ; Drugs, Chinese Herbal/pharmacology* ; Regeneration/drug effects* ; Network Pharmacology ; Signal Transduction ; Macrophages