Dietary fiber deficiency exacerbates intestinal inflammation via miR-6240-enriched gut extracellular vesicles.

Objective Extracellular vesicle (EV)-mediated delivery of microRNAs (miRNAs) plays a crucial role in intercellular communication between tumor cells and their microenvironment, thereby influencing the response to radiotherapy. This study aims to elucidate the effects of EVs derived from irradiated tumor cells on macrophage polarization in oral squamous cell carcinoma (OSCC) and to explore the underlying mechanisms involved. Methods The expression levels of miR-198-5p within EVs isolated from both normoxic and irradiated OSCC cells were quantified. Subsequently, we assessed the impact of these EVs on macrophage polarization by analyzing the expression profiles of M1 and M2 markers. Additionally, bioinformatics analyses were performed to predict potential targets for miR-198-5p, with dual-luciferase assays confirming its interaction with myeloid differentiation primary response 88 (MYD88). Results miR-198-5p was found to be enriched in EVs derived from irradiated OSCC cells (IR-EVs), facilitating its transfer into macrophages. IR-EVs abundant in miR-198-5p inhibited an M2 macrophage polarization phenotype. Furthermore, it was demonstrated that miR-198-5p directly targets MYD88, leading to a reduction in its expression within macrophages. Importantly, overexpression of MYD88 mitigated the inhibitory effect exerted by miR-198-5p-rich IR-EVs on M2 polarization of macrophages. Conclusions Our findings indicate that EVs rich in miR-198-5p derived from irradiated OSCC cells inhibit M2 polarization of macrophages through inhibition of MYD88 expression; thus suggesting that encapsulating miR-198-5p within EVs may represent a promising therapeutic strategy for OSCC.

The aim of this research was to investigate the impact of periplocin (PPLN) on oxaliplatin (OXA) resistance in hepatocellular carcinoma (HCC) cells and offer insights for improving clinical treatment of HCC. The IC50 value of HCC cell lines against OXA was detected by the CCK-8 assay, and an OXA-resistant HepG2 cell line (HepG2/OXA) was constructed. THP-1 cells were induced into M1 or M2 macrophages, and M2 macrophage-conditioned medium (M2-CM) was prepared. M1 and M2 macrophage polarization were detected using RT-qPCR and flow cytometry. CCK-8, EdU staining, clone formation assay, flow cytometry, and western blotting were used to assess the proliferation and apoptosis of HepG2/OXA cells treated with PPLN and M2-CM. Additionally, a nude mouse subcutaneous graft tumor model was constructed. PPLN enhanced the sensitivity of HepG2/OXA cells to OXA, reduced their clone-forming ability, and promoted their apoptosis. Notably, PPLN hindered M0 macrophage polarization to M2 macrophages, while M1 polarization remained unaffected. The proliferation-inhibiting and apoptosis-promoting effects of OXA+PPLN on HepG2/OXA cells were significantly attenuated by the addition of M2-CM, suggesting that PPLN improves the OXA sensitivity of HepG2/OXA cells by hindering M2 macrophage polarization. Furthermore, PPLN inhibited M2 macrophage polarization and improved the OXA sensitivity of HepG2/OXA cells in vivo. In conclusion, PPLN inhibited the proliferation of HepG2/OXA cells, promoted their apoptosis, and inhibited M2 macrophage polarization both in vivo and in vitro, which in turn enhanced the OXA sensitivity of HepG2/OXA cells.

BackgroundLung cancer has the highest incidence among malignant tumors, and its high degree of metastasis and invasion, tendency to metastasis, and mortality rate are the key factors leading to treatment failure and poor prognosis. Tumor-associated macrophages (TAMs), which often exhibit an M2-polarized phenotype, are known to promote tumor progression. Notably, the chemokine CXCL9 has emerged as a critical regulator that can inhibit M2 macrophage polarization, thereby potentially suppressing tumor growth. This study combined clinical sample testing and prognostic analysis with cell behaviorology and molecular biology to systematically investigate the role and regulatory mechanism of CXCL9 in the tumor microenvironment of lung cancer.MethodsTHP-1 cells were induced to differentiate into M1 and M2 macrophages. The effects of M2 macrophages on the proliferation, migration, and invasion of A549 lung adenocarcinoma cells were detected via Cell Counting Kit-8 cell viability, scratch-wound, and Transwell invasion assays. The effects of CXCL9 on M2 macrophage function and the expression of related proteins were detected via enzyme-linked immunosorbent assay, reverse transcription polymerase chain reaction, and Western blotting.ResultsCXCL9 significantly inhibited the promoting effects of M2 macrophages on the proliferation, migration, metastasis and invasion of A549 cells. Specifically, CXCL9 inhibited M2 macrophage polarization by reducing the expression of surface markers CD16, CD32, and CD206. CXCL9 also inhibited the expression of VEGF-C, MMP9, and MMP2, thereby inhibiting tumor cell invasion and metastasis. Moreover, CXCL9 inhibited the activation of the ERK and AKT signaling pathways, further inhibiting tumor cell proliferation and invasion.ConclusionsCXCL9 inhibits the proliferation, migration, metastasis and invasion of lung cancer cells by inhibiting M2 macrophage polarization and function, indicating that CXCL9 may serve as a potential therapeutic target for lung cancer.

Impeding M2 macrophage polarization has been suggested to slow the progression of endometrial cancer (EC). F-box and WD repeat domain containing 7 (FBXW7) reportedly regulates the polarization and migration of macrophages in a multitude of cancers. Our pre-existing bioinformatics predictions showed a negative association between FBXW7 and M2-TAM infiltration in EC. This study aimed to investigate the role of FBXW7 in M2 macrophage polarization in EC by regulating the MYBL2/CCL2 axis. Cancer and adjacent cancerous tissues from patients with EC were collected to detect the differential expression of each factor. CCL2 levels in the cell culture medium were examined using enzyme-linked immunosorbent assay. Immunofluorescence staining was performed to determine the localization of FBXW7 and MYBL2 in EC cells. The number of M2 macrophages marker was determined by flow cytometry. The protein levels of FBXW7, MYBL2, CCL2, CD206, CD163, Arg1, and IL-10 were assessed using western blotting. The ubiquitination level of MYBL2 and the binding relationship between FBXW7 and MYBL2 were verified using co-immunoprecipitation. The effect of FBXW7/MYBL2/CCL2 axis on the malignant progression of EC in vivo was evaluated using tumor xenografts in nude mice. FBXW7 levels were decreased, whereas MYBL2 levels were increased in EC. Overexpression of FBXW7 downregulated CCL2 secretion in EC and inhibited M2 macrophage polarization. FBXW7 promoted the degradation of MYBL2 in a ubiquitination-dependent manner. FBXW7 knockdown inhibited CCL2 secretion by EC cells to restrain M2 macrophage polarization, which was countered by MYBL2 downregulation. In vivo functional assays demonstrated that FBXW7 overexpression significantly suppressed EC xenograft growth and enhanced tumor cell apoptosis. FBXW7 enhanced the ubiquitination and degradation of MYBL2 to reduce CCL2 secretion from EC, which inhibited macrophage polarization to the M2 type.

LncRNA NRON promotes M2 macrophage polarization and alleviates atrial fibrosis through suppressing exosomal miR-23a derived from atrial myocytes

BackgroundMultiple myeloma (MM) is a malignancy where drug resistance often leads to relapse or refractory disease. Chemokine receptor 5 (CCR5) has emerged as a novel therapeutic target. However, the role of CCR5-antagonist Maraviroc (MVC) in M2 macrophage polarization and its potential to enhance Bortezomib sensitivity in MM has not been fully explored.MethodsWe used human bone marrow samples, RPMI 8226 cells, and THP-1 monocytes to investigate CCL3/CCR5 axis. ELISA measured CCL3/CCR5 levels. Knockdown/overexpression vectors modulated expression. Cell proliferation, apoptosis, and macrophage polarization were assessed using CCK8, flow cytometry, and transwell assays. QRT-PCR analyzed CCL3 expression, and western blotting examined PI3K/AKT/RhoA signaling. CCR5 was targeted via siRNAs or MVC. NOD/SCID mouse model evaluated CCL3/CCR5 effects on macrophage polarization and MVC’s impact on Bortezomib efficacy.ResultsCCL3, CCR5, and M2 macrophage markers are upregulated in MM patients, with CCL3/CCR5 expression correlating with M2 macrophage polarization. Myeloma-secreted CCL3 and paracrine CCR5 significantly promoted M2 macrophage polarization by activating PI3K/AKT/RhoA signaling, which in turn enhanced myeloma proliferation, inhibited apoptosis, and reduced Bortezomib sensitivity. MVC inhibited M2 macrophage polarization and improved Bortezomib sensitivity in vitro and xenograft mouse myeloma models.ConclusionsMVC reduced macrophage polarization and enhanced Bortezomib sensitivity in MM cells.

Chenodeoxycholic acid suppresses AML progression through promoting lipid peroxidation via ROS/p38 MAPK/DGAT1 pathway and inhibiting M2 macrophage polarization

BackgroundNon-small cell lung carcinoma (NSCLC) is a type lung cancer with high malignant behaviors. MicroRNAs (miRNAs) are known to be involved in progression of NSCLC. In order to explore potential targets for the treatment of NSCLC, bioinformatics tool was used to analyze differential expressed miRNAs between NSCLC and adjacent normal tissues.MethodsBioinformatics tool was used to find potential targets for NSCLC. Cell proliferation was investigated by Ki67 staining. Cell apoptosis was measured by flow cytometry. mRNA and protein expression in NSCLC cells were detected by RT-qPCR and Western-blot, respectively. Transwell assay was performed to test the cell migration and invasion. In order to investigate the function of exosomal miRNA in NSCLC, in vivo model of NSCLC was constructed.ResultsMiR-770 was identified to be downregulated in NSCLC, and miR-770 agomir could significantly inhibit NSCLC cell proliferation through inducing the apoptosis. Additionally, the metastasis of NSCLC cells was decreased by miR-770 agomir. MAP3K1 was identified to be the target mRNA of miR-770. Meanwhile, tumor cell-derived exosomal miR-770 inhibited M2 macrophage polarization via downregulation of MAP3K1, which in turn suppressed NSCLC cell invasion. Besides, tumor cell-derived exosomal miR-770 markedly decreased NSCLC tumor growth in vivo through suppressing M2 macrophage polarization.ConclusionTumor cell-derived exosomal miR-770 inhibits M2 macrophage polarization to inhibit the invasion of NSCLC cells via targeting MAP3K1. Thus, this study provided a new strategy for the treatment of NSCLC.

Chelidonine-induced inhibition of FBP1 disrupts M2 macrophage polarization and attenuates breast cancer.

Gastric cancer (GC) is a frequently occurring malignancy with poor prognosis. Casein kinase 2 interacting protein-1 (CKIP-1) is a PH domain-containing protein implicated in regulating tumorigenesis and macrophage homeostasis. This study aimed to elucidate the role and potential mechanism of CKIP-1 in the progression of GC. CKIP-1 expression in GC tumor and para-carcinoma tissues was detected using RT-qPCR. Then, human monocyte cell line THP-1 was treated with PMA, interleukin (IL)-4 and IL-13 to induce M2-polarized macrophages. CD206, arginase-1 (Arg-1) and transforming growth factorβ1 (TGFβ1) expression in M2-polarized macrophages with or without CKIP-1 overexpression was evaluated. Moreover, GC cell lines (MKN45 and HGC27 cells) were co-cultured with CKIP-1-overexpressed M2-polarized macrophages, and the viability, migration and invasion of GC cells were measured. Additionally, immunoblotting assessed the expression of JAK/STAT3 signaling-related proteins and STAT3 agonist Colivelin was used to treat GC cells to perform the rescue experiments to analyze the changes of malignant phenotypes of GC cells. Results showed that CKIP-1 was downregulated in GC tissues and M2-polarized macrophages. CKIP-1 overexpression inhibited M2 macrophage polarization and decreased TGFβ1 secretion. Besides, elevated CKIP-1 expression in M2-polarized macrophages inhibited the viability, migration and invasion of GC cells. Furthermore, CKIP-1 overexpression inactivated JAK2/STAT3 signaling in GC cells by inhibiting TGFβ1 level. Specifically, Colivelin treatment abrogated the influences of CKIP-1 upregulation on the malignant phenotypes of GC cells. Collectively, CKIP-1 inhibits M2 macrophage polarization to suppress the progression of GC by inactivating JAK/STAT3 signaling pathway.

HuangLong oral liquid alleviates cough variant asthma in mice via inhibiting M2 macrophage chemotaxis and polarization by regulating the PI3K/AKT/ERK pathway.

Circular RNAs (circRNAs) have been shown to mediate tumor-associated macrophages (TAMs) to regulate the development of many cancers, including lung adenocarcinoma (LUAD). However, whether circ_0001715 regulates LUAD progression by mediating TAMs polarization remains uncertain. Monocytes (THP-1) were treated with PMA to induce M0 macrophages. M0 macrophages were incubated with LUAD cells-derived exosomes and then cocultured with LUAD cells. The levels of circ_0001715, M2 macrophage markers, microRNA (miR)-205-5p, and triggering receptor expressed on myeloid cells-2 (TREM2) were examined using quantitative real-time PCR. Flow cytometry was performed to assess M2 macrophage surface marker CD206. Cell proliferation, migration and invasion were determined using cell counting kit 8, EdU, colony formation and transwell assays. Dual-luciferase reporter assay was used to investigate the interactions between miR-205-5p and circ_0001715 or TREM2. Circ_0001715 knockdown inhibited M2 macrophage polarization and its overexpression had an opposite effect. After M0 macrophages transfected with si-circ_0001715 were cocultured with LUAD cells, the proliferation and metastasis of LUAD cells were markedly reduced. Exosomes transferred circ_0001715 between M0 macrophages and LUAD cells. Exosomal circ_0001715 promoted M2 macrophage polarization to increase LUAD cell proliferation and metastasis. In terms of mechanism, circ_0001715 sponged miR-205-5p to positively regulate TREM2. TREM2 upregulation also could promote LUAD cell proliferation and metastasis via increasing M2 macrophage polarization. In addition, TREM2 knockdown reversed the effect of exosomal circ_0001715 on M2 macrophage polarization and LUAD cell progression. Exosomal circ_0001715 led to LUAD cell proliferation and metastasis by promoting M2 macrophage polarization via the miR-205-5p/TREM2 axis.

During an immune response, macrophages undergo systematic metabolic rewiring tailored to support their functions. Branched-chain amino acid (BCAA) metabolism has been reported to modulate macrophage function; however, its role in macrophage alternative activation remain unclear. We aimed to investigate the role of BCAA metabolism in macrophage alternative activation. The metabolomics of BMDM-derived M0 and M2 macrophages were analyzed using LC-MS. BCAAs were supplemented and genes involved in BCAA catabolism were inhibited during M2 macrophage polarization. The expression of M2 marker genes was assessed through RT-qPCR, immunofluorescence, and flow cytometry. Metabolomic analysis identified increased BCAA metabolism as one of the most significantly rewired pathways upon alternative activation. M2 macrophages had significantly lower BCAA levels compared to controls. BCAA supplementation promoted M2 macrophage polarization both in vitro and in vivo and increased oxidative phosphorylation in M2 macrophages. Blocking BCAA entry into mitochondria by knockdown of SLC25A44 inhibited M2 macrophage polarization. Furthermore, M2 macrophages polarization was suppressed by knockdown of Branched-chain amino-acid transaminase 2 (BCAT2) and branched chain keto acid dehydrogenase E1 subunit alpha (BCKDHA), both of which are key enzymes involved in BCAA oxidation. Overall, our findings suggest that BCAA catabolism plays an important role in polarization toward M2 macrophages.

MBD2 deficiency attenuates CCl4-induced hepatic fibrosis by inhibiting M2 macrophage polarization.

Background: Asthma, the most common chronic respiratory disorder affecting individuals of all ages, is driven by inflammation that leads to airway hyperresponsiveness, airway wall remodeling, and mucus production. While inhaled corticosteroids remain the primary treatment despite their limitations, further research into the molecular mechanisms of asthma is needed to identify new therapeutic targets. Methods: A mouse model of asthma was created by treating mice with OVA. HE and PAS staining were used to detect histopathology. Gene and protein expression levels were assessed using qPCR, Western blot, and ELISA. The relationship between USP4 and SRC-1 was examined using Co-IP assay. The ubiquitination levels of SRC-1 were detected using IP assay while macrophage polarization was analyzed by flow cytometry. Results: The ovalbumin-induced mouse model of asthma exhibited a large quantity of inflammatory cell infiltration, proliferation of goblet cells, and increased mucus secretion. SRC-1 expression was upregulated in an OVA-induced mouse model of asthma. Downregulation of SRC-1 reduced macrophage polarization to the M1 phenotype, protecting against OVA-induced asthma, whereas SRC-1 overexpression inhibited M2 macrophage polarization by suppressing the NF-kB signaling pathway. Furthermore, USP4 was found to deubiquitinate SRC-1, enhancing its protein stability. The regulatory axis between USP4 and SRC-1 was validated in vivo. Conclusion: This study demonstrates that USP4 regulates the deubiquitination of SRC-1, which inhibits M2 macrophage polarization and aggravates asthma-related inflammation. These findings suggest that USP4 and SRC-1 may serve as potential therapeutic targets for asthma treatment. Highlights SRC-1 is upregulated in OVA-induced asthma and correlated to macrophage. SRC-1 knockdown reduces M1 macrophage polarization and airway inflammation in the asthma model. SRC-1 overexpression or USP4 overexpression suppresses IL-4-induced M2 polarization via the NF-κB pathway. USP4 regulates the deubiquitination of SRC-1, influencing macrophage polarization and inflammation.