M2 Macrophage Markers Research Articles

BIOM-38. OPPOSING EFFECTS OF LINKED CX3CR1 GERMLINE VARIANTS ON INCIDENCE, SURVIVAL, AND IMMUNE ACTIVATION IN GLIOMA

Abstract Linkage-disequilibrium connects CX3CR1 V249I and T280M single-nucleotide polymorphisms; V249I occurs as a single-variant (SV) and T280M exclusively as a double-variant (DV) concurrent with V249I. The effect of these combined haplotypes remains unexplored in glioma. We identified CX3CR1 haplotypes in internal LGG and TCGA GBM cohorts and analyzed median overall survival (mOS). The proportion of each haplotype in glioma and normal patients was assessed via meta-analysis. Bulk RNAseq analysis was conducted in TCGA and internal GBM cohorts and scRNAseq in internal IDH mutant gliomas. In LGG, SV improved mOS (n=14, 21.03yrs) by twofold compared to WT (n=45, 9.41yrs) and DV (n=31, 10.49yrs; p=0.037). In TCGA GBM, SV (n=69, 15.65mo) improved mOS over DV (n=106, mOS 11.74mo; p=0.044). In combined meta-analysis, SV patients had increased risk for glioma development (OR 1.11, 1.03-1.19 p = 0.006) and the WT genotype was protective (OR 0.95, p=0.048). Collagen genes associated with increased immunosuppression (COL6A3: log2FC=2.33, p-adj=0.004; COL6A2: log2FC=1.55, p-adj=.059) were reduced in SV. MME, an endopeptidase associated with radiation resistance, was downregulated in SV (log2FC=3.29, p-adj=2.53e-6). MN1, associated with improved glioma survival, was upregulated in SV (log2FC=-1.76, p-adj=0.001). CCL18, an immunosuppressive chemokine associated with M2 macrophage polarization was reduced in SV (log2FC=2.36, p-adj=0.014). Thus, concomitant with its improved survival, SV is biologically distinct from DV and WT. Using scRNAseq, myeloid-derived cells (microglia/macrophages; 7758 cells) were re-clustered, identifying fourteen clusters. Cells clustered by CX3CR1 status, with 58.2% of SV cells in cluster five and 84.9% of DV cells in clusters six or seven. Cluster five over-expressed IL1B (average-log2FC 3.16), a tumor-suppressive M1 macrophage marker. Clusters six and seven were characterized by IFIT genes (IFIT3 average-log2FC 2.72 and 2.16 respectively), which corresponds to glioma associated microglia from recent scRNAseq microglial atlases. We demonstrate that CX3CR1 SV has improved survival and reduced immunosuppression over wildtype and this is lost with in the linked CX3CR1 DV genotype.

Nicotine promotes M2 macrophage polarization through α5-nAChR/SOX2/CSF-1 axis in lung adenocarcinoma

α5-nicotinic acetylcholine receptor (α5-nAChR) plays a vital part in lung adenocarcinoma (LUAD). However, it is not comprehensively understood that how the α5-nAChR affects LUAD. Through diverse bioinformatics analyses and immunohistochemistry, the expressions of α5-nAChR and SOX2 as well as their relations were dissected. α5-nAChR regulated the differentiation of monocytes into M2 macrophages by targeting the STAT3/SOX2/CSF-1 signaling in the coculture system by western blotting and ChIP. α5-nAChR-mediated macrophage-mediated LUAD cell migration via SOX2/CSF-1 signaling in the cocultured medium. Correlations of α5-nAChR, SOX2 and M2 phenotype tumor-associated macrophages (TAMs) were validated in mouse LUAD models and clinical samples. α5-nAChR expression was connected to SOX2 expression, smoking and bad prognosis of LUAD among clinical samples. Nicotine-induced SOX2 expression was mediated by α5-nAChR via STAT3. Additionally, SOX2-mediated macrophage colony-stimulating factor (CSF-1) expression contributed to LUAD progression in vitro. Furthermore, α5-nAChR expression was strongly linked to pSTAT3, SOX2 and M2 macrophage marker CD206 expression and negatively correlated with M1 macrophage marker CD86 expression in vivo. It is indicated that M2 macrophages are mediated by the new α5-nAChR /SOX2/CSF-1 axis in nicotine-related LUAD, which is a potential therapeutic strategy for cancer.

The oncogenic functions of SPARCL1 in bladder cancer.

Secreted protein, acidic and rich in cysteine-like 1 (SPARCL1) belongs to the SPARC family of matricellular proteins. However, underlying functions of SPARCL1 in bladder cancer (BCa) remain understudied. We performed an integrated search for the expression patterns of SPARCL1 in relation to various clinicopathological features of BCa. We then carried out Gene Ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and gene set enrichment analysis (GSEA). Furthermore, we investigated the correlations between SPARCL1 and immunological features, such as tumour mutation burden (TMB), immune activation processes, immune checkpoint expression, tumour immune dysfunction and exclusion (TIDE) scores, and chemotherapeutic sensitivity in BCa. Our analysis revealed that SPARCL1 was downregulated across multiple cancers. In BCa, elevated SPARCL1 was linked with advanced histopathologic stage, higher T and N stage, and poorer prognosis in the clinical cohort. Invitro experiments demonstrated that increased SPARCL1 expression inhibited cell proliferation, migration, and invasion. Additionally, highly expressed SPARCL1 was linked to elevated immune, stromal and ESTIMATE scores, as well as an increase in naive B cells, M2 macrophages, and resting mast cells. We observed a moderate correlation between SPARCL1 expression and CD163, VSIG4 and MS4A4A, which are markers of M2 macrophages. Furthermore, SPARCL1 expression was positively related to TMB, immune activation processes, TIDE scores, immune checkpoint expression, and chemotherapeutic sensitivity in BCa. Our study highlights the potential involvement of SPARCL1 in macrophage recruitment and polarization and suggests its utility as a biomarker for prognosis in BCa.

Licochalcone A loaded multifunctional chitosan hyaluronic acid hydrogel with antibacterial and inflammatory regulating effects to promote wound healing

The wound healing process is characterized by persistent infection and long-term inflammation. The licochalcone A (LicA) has the potential for skin wound healing and needs a good drug-loading platform to apply its antibacterial and anti-inflammatory effects. In this study, the LicA@chitosan (CS) -hyaluronic acid (HA) hydrogel with antibacterial and anti-inflammatory was developed for wound healing in mice. The SEM displayed that the hydrogel had an obvious porous structure and was very suitable to be used as a delivery carrier for LicA. The FTIR results suggested that the LicA can be effectively loaded in the CS-HA hydrogel. Variable strain scanning, frequency scanning and temperature scanning indicated that the LicA@CS-HA hydrogel can maintain the gel state. The LicA@CS-HA hydrogel had good biological safety, can inhibit the activity of Escherichia coli and Staphylococcus aureus, and can release LicA stably. The LicA@CS-HA hydrogel also has good adhesion and hemostatic properties. Finally, the LicA@CS-HA hydrogel significantly accelerated wound healing in mice skin injury model, and reduced inflammation and orderly collagen deposition were observed by HE and Masson staining. The immunohistochemistry indicated that the LicA@CS-HA hydrogel induced the positive expression of CD31, VEGF, and HIF-1α promoted neovascularization. The LicA@CS-HA hydrogel also down-regulated the expression of M1 macrophage markers CD86, IL-6, and TNF-α, and increased the expression of M2 macrophage markers CD206, IL-4, and IL-10 proteins. The molecular docking demonstrated that the target proteins had better binding activity to LicA. Collectively, the LicA@CS-HA hydrogel has broad application prospects in promoting wound healing.

The role of cellular senescence in aortic dissection

Abstract Background Aortic dissection (AD) is a catastrophic disease with high mortality. Survived patients frequently suffer from serious complications due to progressive destruction of the aortic walls. Recently we have reported that cell proliferation precedes the inflammatory response which is important in AD development and progression. Since cell proliferation promotes cellular senescence that can induce inflammatory response through SASP (senescence-associated secretary phenotype), we hypothesized that cellular senescence plays a critical role in AD pathogenesis. Purpose To investigate if cellular senescence contributes to AD pathogenesis in mouse AD model. Methods and Results A mouse AD model was created by the continuous infusion of beta-aminopropionitrile and angiotensin II (BAPN+AngII) for 14days. BAPN+AngII infusion induced senescence markers and senescent cells in mouse AD model. Senescent cells, as demonstrated by the expression of senescence-associated beta-galactosidase, were evident in intimal endothelial cells, medial smooth muscle cells, adventitial macrophages, and fibroblasts. Rapamycin, an inhibitor of mTOR pathway, suppressed the expression of senescent cells on the aortic tissue and the senescent marker protein expression. To examine the role of cellular senescence in AD, we orally administrated ABT263 known as "senolytics" that eliminates senescent cells. ABT263 treatment prevented cellular senescence in mouse AD model. The AD mortality of ABT263 group was 35%, which was lower than that of vehicle group (66.7%, P < 0.05 by log-rank test). The severity of AD, as assessed by the lesion length in vehicle group was 33.2 ± 3.1mm, whereas that in ABT263 group was 24.6 ± 1.8mm (P < 0.05). Transcriptome analysis revealed that ABT263 treatment suppressed the immune and inflammatory response in the aorta before AD onset. Quantitative RT-PCR confirmed that ABT263 treatment prevented the induction of p21Cip1, interleukin-6, several chemokines and M1 macrophage marker CD80 and CD86. It is known that Jnk activation induces SASP and accelerates cellular senescence. Western blotting confirmed that ABT263 reduced the ratio of pJnk to total Jnk, which was induced by BAPN + AngⅡ. Moreover, aortic smooth muscle cells（SMCs）remained contractile phenotype in ABT263 group, whereas BAPN+AngII reduced that phenotype in vehicle group. Conclusions Cell proliferation via mTOR pathway causes cellular senescence in mouse AD model. Jnk activation was confirmed in mouse AD model. Cellular senescence contributes to AD progression and death associated with inflammatory responses including SASP, the differentiation to M1 macrophage, and the phenotype change of SMCs.Cellular senescence represents a potential predictor and a therapeutic target for AD.

Poly-D,L-Lactic Acid Filler Attenuates Ultraviolet B-Induced Skin Pigmentation by Reducing Destruction of the Basement Membrane.

Poly-D,L-lactic acid (PDLLA) filler, which increases volume and collagen synthesis, is used for skin rejuvenation. PDLLA filler also increases M2 macrophages and IL-10. Ultraviolet (UV) radiation induces dermal hyperpigmentation by disrupting the basement membrane (BM), allowing melanin to move into the dermis. Therefore, using UV-irradiated macrophages and animal skin, we determined whether PDLLA filler decreased M1 macrophages and skin inflammation, thereby reducing BM destruction and dermal hyperpigmentation. UV radiation increased the M1 macrophage marker CD86 and TNF-α expression, which was inhibited by the treatment of macrophages with PDLLA. In fibroblasts treated with conditioned medium from UV-irradiated macrophages, NF-κB activity, NLRP3 inflammasome components (NLRP3, ASC, and pro-caspase-1), IL-18, MMP2, and MMP9 increased, but all decreased after PDLLA treatment. Similar to the in vitro study, UV-irradiated mouse skin showed increased CD86, NLRP3, ASC, pro-caspase-1, MMP2, and MMP9, which decreased after PDLLA injection. Disruption of the lamina densa of the BM and dermal pigmentation increased after UV irradiation and decreased after PDLLA injection. In conclusion, PDLLA reduced dermal pigmentation by decreasing BM destruction in UV-irradiated skin. PDLLA has the potential to reduce dermal pigmentation by regenerating the BM.

Astragaloside IV augments anti-PD-1 therapy to suppress tumor growth in lung cancer by remodeling the tumor microenvironment.

Programmed cell death protein-1 (PD-1) inhibitors are increasingly utilized in the treatment of lung cancer (LC). Combination therapy has recently gained popularity in treating LC. This study aimed to assess the efficacy of combining Astragaloside IV (AS-IV) and anti-PD-1 in LC. C57BL/6J mice were subcutaneously injected with Lewis lung carcinoma (LLC) cells. After 3 weeks, the animals were sacrificed, and the tumors were harvested for analysis. Ki-67 immuno-labeling and TUNEL assay were used for evaluating cell proliferation and apoptosis in tumor tissues. In addition, anti-cleaved caspase 3 was used for immunolabelling of apoptotic cells. Immune cell infiltration (macrophages and T cells) and gene expression in tumor tissues were also investigated by using immunofluorescence staining. Compared to treatment with anti-PD-1 or AS-IV, the combination of AS-IV and anti-PD-1 notably reduced tumor volume and weight of LLC-bearing mice. Additionally, the combination treatment strongly induced the apoptosis and suppressed the proliferation in tumor tissues through inactivating PI3K/Akt and ERK signaling pathways, compared to single treatment group. Moreover, the combination treatment elevated levels of the M1 macrophage marker mCD86, reduced levels of the M2 macrophage marker mCD206, as well as upregulated levels of the T cell activation marker mCD69 in tumor tissues. Collectively, the combination treatment effectively inhibited tumor growth in LLC mice through promoting M1 macrophage polarization and T cell activation. These findings showed that combining AS-IV with anti-PD-1 therapy could be a promising therapeutic approach for LC.

Association of preoperative seizures with reduced expression of soluble CD163, an M2 macrophage marker, in the cerebrospinal fluid in isocitrate dehydrogenase wild-type glioblastoma.

To investigate the relationship between the tumor microenvironment (TME), tumor-related seizures (TRS), and cerebrospinal fluid (CSF) markers that predict preoperative seizures in patients with glioblastoma. In total, 47 patients with isocitrate dehydrogenase (IDH) wild-type glioblastoma who underwent preoperative CSF examination, 3-T magnetic resonance spectroscopy (MRS), and neurological surgery between January 2017 and December 2023 were included. We measured the concentrations of soluble CD163 (sCD163), a soluble form of the M2 macrophage marker, in the CSF, the metabolite concentration on MRS, and the number of CD163-positive M2 macrophages in the tumor tissue. Factors associated with preoperative seizures were examined. Twelve patients (25.5%) had preoperative seizures. sCD163 levels in the CSF were positively correlated with the number of CD163-positive M2 macrophages in the tumor tissue, and both were significantly lower in the preoperative seizure group than in the non-preoperative seizure group (p = 0.0124 and p < 0.0001, respectively). MRS indicated that only glutathione (GSH) concentrations were higher in the preoperative seizure group than in the non-preoperative seizure group (2.55 mM and 1.87 mM, respectively; p = 0.0171). CD163-positive M2 macrophages were inversely correlated with GSH levels. sCD163 in the CSF had a high predictive accuracy (sensitivity, 91.7%; specificity, 54.3%; and area under the receiver operator curve, 0.745) for preoperative seizures. The CSF level of sCD163 is useful for predicting the TME and preoperative seizures in IDH wild-type glioblastoma.

LPS-induced systemic inflammation is suppressed by the PDZ motif peptide of ZO-1 via regulation of macrophage M1/M2 polarization.

The gram-negative bacterium lipopolysaccharide (LPS) is frequently administered to generate models of systemic inflammation. However, there are several side effects and no effective treatment for LPS-induced systemic inflammation. PEGylated PDZ peptide based on zonula occludens-1 (ZO-1) was analyzed for its effects on systemic inflammation induced by LPS. PDZ peptide administration led to the restoration of tissue injuries (kidney, liver, and lung) and prevented alterations in biochemical plasma markers. The production of pro-inflammatory cytokines was significantly decreased in the plasma and lung BALF in the PDZ-administered mice. Flow cytometry analysis revealed the PDZ peptide significantly inhibited inflammation, mainly by decreasing the population of M1 macrophages, and neutrophils (immature and mature), and increasing M2 macrophages. Using RNA sequencing analysis, the expression levels of the NF-κB-related proteins were lower in PDZ-treated cells than in LPS-treated cells. In addition, wild-type PDZ peptide significantly increased mitochondrial membrane integrity and decreased LPS-induced mitochondria fission. Interestingly, PDZ peptide dramatically could reduce LPS-induced NF-κB signaling, ROS production, and the expression of M1 macrophage marker proteins, but increased the expression of M2 macrophage marker proteins. These results indicated that PEGylated PDZ peptide inhibits LPS-induced systemic inflammation, reducing tissue injuries and reestablishing homeostasis, and may be a therapeutic candidate against systemic inflammation.

LPS-induced systemic inflammation is suppressed by the PDZ motif peptide of ZO-1 via regulation of macrophage M1/M2 polarization

The gram-negative bacterium lipopolysaccharide (LPS) is frequently administered to generate models of systemic inflammation. However, there are several side effects and no effective treatment for LPS-induced systemic inflammation. PEGylated PDZ peptide based on zonula occludens-1 (ZO-1) was analyzed for its effects on systemic inflammation induced by LPS. PDZ peptide administration led to the restoration of tissue injuries (kidney, liver, and lung) and prevented alterations in biochemical plasma markers. The production of pro-inflammatory cytokines was significantly decreased in the plasma and lung BALF in the PDZ-administered mice. Flow cytometry analysis revealed the PDZ peptide significantly inhibited inflammation, mainly by decreasing the population of M1 macrophages, and neutrophils (immature and mature), and increasing M2 macrophages. Using RNA sequencing analysis, the expression levels of the NF-κB-related proteins were lower in PDZ-treated cells than in LPS-treated cells. In addition, wild-type PDZ peptide significantly increased mitochondrial membrane integrity and decreased LPS-induced mitochondria fission. Interestingly, PDZ peptide dramatically could reduce LPS-induced NF-κB signaling, ROS production, and the expression of M1 macrophage marker proteins, but increased the expression of M2 macrophage marker proteins. These results indicated that PEGylated PDZ peptide inhibits LPS-induced systemic inflammation, reducing tissue injuries and reestablishing homeostasis, and may be a therapeutic candidate against systemic inflammation.

Establishment of mouse alveolar macrophage extraction standard and its application in the evaluation of efficacy in lung metastasis of colorectal cancer

Introduction: Alveolar macrophages (AM) are involved in the development and progression of a variety of lung diseases. It is of great significance to explore the pathogenesis of diseases and evaluate the efficacy of drugs. However, there is no standard process for extracting primary AM. Nitidine chloride is an alkaloid extracted from Zanthoxylum nitidum (Roxb.) DC., which has an anti-tumour pharmacological effect. However, there is no evidence that nitidine chloride has a direct effect on CRC cell lung metastasis. The purpose of this study was to establish a standard for the extraction of primary AM from mice and to investigate the pharmacodynamics of nitidine chloride in mice with lung metastases to colorectal cancer. Methods: The standard for the extraction of mouse primary AM by lavage was established. Western blot and PCR were used to detect the regulatory mechanism of nitidine chloride in the treatment of lung metastasis in mice by macrophage phenotype and glycolysis level. Results: The results showed that sufficient quantity and quality of primary AM could be obtained by optimising extraction steps, and AM obtained by this method could accurately reflect disease progression. At the same time, nitidine chloride can effectively reduce colorectal cancer lung metastasis in mice. From the mechanism, nitidine chloride can inhibit the expression of M2 macrophage markers and the levels of mRNA and proteins of the glycolysis-limiting enzyme. Conclusions: Our results show that primary AM that accurately reflect disease and assess pharmacological effects can be obtained using our established criteria. The inhibitory effect of nitidine chloride on colorectal cancer lung metastasis may be attributed to its regulation of macrophage phenotype and glycolysis.

N6‑methyladenosine methyltransferase METTL14 is associated with macrophage polarization in rheumatoid arthritis.

Rheumatoid arthritis (RA) is largely caused by the inflammatory response triggered by macrophage polarization. Through epigenetic reprogramming, the inflammatory state of macrophages can be modified. Macrophage polarization is associated with the RNA epigenetic alteration N6-methyladenosine (m6A) RNA methylation. However, the specific function and underlying mechanisms of m6A methylation in the role of macrophage polarization in RA remain to be elucidated. The mRNA expression levels of m6A methylase genes and signaling pathway components associated with RA macrophages were determined in the present study using reverse-transcription quantitative PCR. Methyltransferase 14 (METTL14) protein expression levels were determined using western blot analysis, and the levels of specific cellular secretion factors were determined using ELISA and flow cytometry. The results of the present study demonstrated that elevated METTL14 expression was associated with joint tenderness, and METTL14 expression was positively correlated with both C-reactive protein and rheumatoid factor expression levels. Moreover, METTL14 exhibited potential in the prediction of visual analogue scale. Pro-inflammatory cytokines (TNF-α) and M1 macrophage markers (CD68+CD86+) were also positively associated with METTL14 expression. The results of the Kyoto Encyclopedia of Genes and Genomes analysis revealed that METTL14 was strongly associated with the MAPK signaling pathway. Notably, JNK and ERK2 exhibited a positive correlation with the M1 macrophage marker, CD68+CD86+, which was positively associated with the pro-inflammatory factor, TNF-α. JNK and ERK2 expression levels were markedly increased in the METTL14 high-expression group, compared with in the low-expression group; however, p38 and ERK1 expression levels were not significantly different between these groups. Collectively, the results of the present study demonstrated that METTL14 expression was significantly increased in the peripheral blood and synovial tissue of patients with RA, highlighting the potential association with both immunoinflammatory markers and clinical symptoms. In addition, it was suggested that METTL14 may exacerbate the downstream inflammatory response, through mediating macrophage polarization via the MAPK pathway.

The Role of Macrophages in Airway Disease Focusing on Porcine Reproductive and Respiratory Syndrome Virus and the Treatment with Antioxidant Nanoparticles.

Lung macrophage cells play a critical role in various lung diseases, and their state can change depending on the progression of the disease by inducing either an inflammatory or anti-inflammatory state. In this review, the potential therapeutic effects of treatment with antioxidant nanoparticles in air-borne diseases focusing on porcine reproductive and respiratory virus (PRRSV), considering reactive oxygen species (ROS) as one of the factors that regulate M1 and M2 macrophages in the inflammatory and anti-inflammatory states, respectively, was described. In addition, the author examines the status of protein structure research on CD163 (one of the markers of anti-inflammatory M2 macrophages) in human and veterinary lung diseases.

Germacrone ameliorates acute lung injury induced by intestinal ischemia-reperfusion by regulating macrophage M1 polarization and mitochondrial defects.

Intestinal ischemia-reperfusion (I/R) injury severely affects the lungs. Germacrone (Ger) possesses anti-inflammatory and antioxidant properties. However, it is unclear whether it protects the lungs from I/R injury. In this study, we elucidate the mechanisms by which Ger protects lungs from I/R injury. C57BLKS/J male mice are subjected to I/R injury via complete clamping of the superior mesenteric artery. Ger is administered before intestinal I/R. Mitochondrial morphology is observed via electron microscopy. The histopathology of the lung tissues is monitored via hematoxylin-eosin and immunofluorescence staining. The mitochondrial oxygen consumption rate is measured via an XF96 extracellular flux analyzer. In the I/R mouse model, lung specimens present significant lung damage accompanied by increases in the levels of collagen III, vimentin, and α-SMA in lung tissues. After treatment with Ger, lung impairment and fibrosis in I/R-induced acute lung injury (ALI) model mice are restored, suggesting that Ger improves I/R-ALI. In addition, Ger administration decreases the release of inflammatory factors such as IL-1β, IL-6, and COX2, as well as the expressions of M1 macrophage markers, facilitating cell survival in the I/R-ALI model. Additionally, Ger (EC50: 47.16 μM) ameliorates mitochondrial dysfunction by increasing I/R-ALI-induced apoptosis, increasing the expression of SIRT1, and reducing the levels of HIF1-α, Nrf2, and OGG1 in MLE-12 cells. Ger may affect macrophage polarization and improve subsequent mitochondrial defects through the SIRT1-HIF1α-Nrf2 signaling pathway in MLE-12 cells, which ultimately improves lung function and lung inflammation in the I/R-ALI model.

Vitamin D3 reduces the expression of M1 and M2 macrophage markers in breast cancer patients.

Vitamin D3 (VD) is known for its immunomodulatory and anticancer effects. This study aimed to characterize tumor-associated macrophages (TAMs) in breast cancer (BC) and assess the influence of VD and its active metabolite, calcitriol, on their polarization. TAMs were isolated from BC patients and characterized. Monocytes were differentiated into macrophage classes (M0, M1, M2a, M2c) and treated ex vivo with calcitriol. The expression of VD-related proteins in tumor tissue was correlated with TAMs and monocyte-derived macrophages (MDMs) characteristics. TAM expression of CD200R, CD204, CD80, HLA-DR, and CD44 was negatively correlated with CYP27B1 in selected patient groups. Patients with high CYP27B1 tumor expression showed significantly lower CD200R, CD204, and CD44 expression. In patients with normal VD levels and premenopausal, CD80 expression in M2a and M2c MDMs (control, untreated ex vivo with calcitriol) was negatively correlated with plasma VD. Calcitriol reduced HLA-DR during MDM differentiation in all patients; CD80 decrease significantly except in patients with normal VD levels or metastasis. Calcitriol also decreased CD163 expression. The decrease in both M1 and M2 macrophage markers by calcitriol or their negative correlation with CYP27B1 indicate the modulatory, but rather anticancer activity of VD. The intensity of these effects was the strongest in postmenopausal patients and those without metastases.

Distinct activation of M1 and M2 macrophages in the primary pterygium lymphangiogenesis

The precise role and innate immunological mechanisms underlying lymphangiogenesis in pterygium remain unclear. This study aimed to investigate the presence of M1 and M2 macrophages and their correlation with pro-lymphangiogenic activation and lymphatic endothelial expression in human pterygium stromal tissues. We analyzed human pterygium and subject-matched normal conjunctival tissues for the expression of these factors and conducted in vitro experiments to assess interactions between macrophages and pterygium fibroblasts. Myeloid and M1 macrophage markers were upregulated in pterygium. M1 macrophages were associated with the upregulation of pro-lymphangiogenic vascular endothelial growth factor C (Vegfc) in pterygium tissues and induced inflammatory signals in pterygium fibroblasts. In contrast, lymphatic vessel endothelial hyaluronan receptor 1 (Lyve1) expression was associated with M2 markers but not with M1 markers. Notably, the clinical severity of pterygium was inversely correlated with the expression of the M2 marker Cd163. These findings suggest that M1 and M2 macrophages play distinct roles in the pathogenesis of pterygium, with M1 macrophages enhancing lymphangiogenic stimulation and inflammatory responses, while M2 macrophages are associated with Lyve1 expression and reduced severity of pterygium. Understanding these mechanisms may advance our current understanding of lymphatic biology in pterygium.

SGLT2 inhibitors ameliorate NAFLD in mice via downregulating PFKFB3, suppressing glycolysis and modulating macrophage polarization.

Sodium-glucose co-transporter 2 (SGLT2) inhibitor (SGLT2i) is a novel class of anti-diabetic drug, which has displayed a promising benefit for non-alcoholic fatty liver disease (NAFLD). In this study, we investigated the protective effects of SGLT2i against NAFLD and the underlying mechanisms. The db/db mice and western diet-induced NAFLD mice were treated with dapagliflozin (1 mg·kg-1·d-1, i.g.) or canagliflozin (10 mg·kg-1·d-1, i.g.) for 8 weeks. We showed that the SGLT2i significantly improved NAFLD-associated metabolic indexes, and attenuated hepatic steatosis and fibrosis. Notably, SGLT2i reduced the levels of pro-inflammatory cytokines and chemokines, downregulated M1 macrophage marker expression and upregulated M2 macrophage marker expression in liver tissues. In cultured mouse bone marrow-derived macrophages and human peripheral blood mononuclear cell-derived macrophages, the SGLT2i (10, 20 and 40 μmol/L) significantly promoted macrophage polarization from M1 to M2 phenotype. RNA sequencing, Seahorse analysis and liquid chromatography-tandem mass spectrometry analysis revealed that the SGLT2i suppressed glycolysis and triggered metabolic reprogramming in macrophages. By using genetic manipulation and pharmacological inhibition, we identified that the SGLT2i targeted PFKFB3, a key enzyme of glycolysis, to modulate the macrophage polarization of M1 to M2 phenotype. Using a co-culture of macrophages with hepatocytes, we demonstrated that the SGLT2i inhibited lipogenesis in hepatocytes via crosstalk with macrophages. In conclusion, this study highlights a potential therapeutic application for repurposing SGLT2i and identifying a potential target PFKFB3 for NAFLD treatment.

Acetylation of TIR domains in the TLR4-Mal-MyD88 complex regulates immune responses in sepsis

Activation of the Toll-like receptor 4 (TLR4) by bacterial endotoxins in macrophages plays a crucial role in the pathogenesis of sepsis. However, the mechanism underlying TLR4 activation in macrophages is still not fully understood. Here, we reveal that upon lipopolysaccharide (LPS) stimulation, lysine acetyltransferase CBP is recruited to the TLR4 signalosome complex leading to increased acetylation of the TIR domains of the TLR4 signalosome. Acetylation of the TLR4 signalosome TIR domains significantly enhances signaling activation via NF-κB rather than IRF3 pathways. Induction of NF-κB signaling is responsible for gene expression changes leading to M1 macrophage polarization. In sepsis patients, significantly elevated TLR4-TIR acetylation is observed in CD16+ monocytes combined with elevated expression of M1 macrophage markers. Pharmacological inhibition of HDAC1, which deacetylates the TIR domains, or CBP play opposite roles in sepsis. Our findings highlight the important role of TLR4-TIR domain acetylation in the regulation of the immune responses in sepsis, and we propose this reversible acetylation of TLR4 signalosomes as a potential therapeutic target for M1 macrophages during the progression of sepsis.

Accelerated BDNF expression in visceral white adipose tissues following high-fat diet feeding in mice.

Brain-derived neurotrophic factor (BDNF) is expressed in the white adipose tissues (WATs), and the expression increases during high-fat diet (HFD) feeding, implicating its role in obesity. Here, we focused on BDNF expression in epididymal WAT (eWAT), a visceral adipose tissue, in mice. During 2 weeks of HFD feeding, Bdnf mRNA expression in eWAT slightly increased, but a robust increase was observed after 8 weeks of HFD feeding. This upregulation of Bdnf mRNA was correlated with significant induction of hypoxia-inducible factor 1α (Hif1α) and platelet-derived growth factor subunit B (Pdgfb) mRNA in eWAT following 8 weeks of HFD feeding. Furthermore, the increased expression of the M1 macrophage markers was strongly correlated with the elevation of Bdnf mRNA in the eWAT. Notably, 8 weeks of HFD feeding significantly elevated Tnfα mRNA expression in eWAT, while no such induction was observed in inguinal WAT (iWAT). In contrast, the expression of Adipoq (adiponectin), implicated in improved insulin sensitivity and anti-inflammatory effects, was significantly upregulated in iWAT, but not in eWAT. Thus, our study may show the role of BDNF in eWAT in obesity models, potentially contributing to the pathological state of visceral adipose tissues.

Reveal the pharmacodynamic substances and mechanism of an edible medicinal plant Platycodonis radix inhibits tumor

Accumulating evidence suggests that M2-polarized tumor-associated macrophages (TAMs) play a crucial role in cancer progression, making them a promising target for therapy. This study explored the molecular mechanisms by which Platycodon grandiflorum regulates M2 polarization of TAMs to exert anti-tumor effects. UPLC-MS identified the chemical composition and blood-absorbed components. Immunohistochemistry and Western blot detected TAM infiltration and proliferation pathways, while q-RT-PCR measured M2 macrophage marker expression. Our findings showed that PR reduces melanoma weight, inhibits the mTOR pathway, and suppresses M2-polarized macrophages. PR downregulates JAK2 and p-STAT3, promotes JAK2 degradation, and enhances ubiquitination. Molecular docking indicated strong affinities between Platycodin D components and JAK2/STAT3, highlighting PR’s potential in regulating TAMs and offering new clinical insights.