RETRACTED ARTICLE: Exosomal DLX6-AS1 from hepatocellular carcinoma cells induces M2 macrophage polarization to promote migration and invasion in hepatocellular carcinoma through microRNA-15a-5p/CXCL17 axis

There is increasing evidence that exosome-mediated transmission of microRNA (miRNAs) helps to connect tumor-associated macrophages and cancer cells, including lung adenocarcinoma (LUAD) cells. To identify the role of miR-3153 in LUAD progression and M2 macrophage polarization and explore its regulatory mechanism. The relevant molecular mechanisms were analyzed and validated through mechanistic assays. In vitro functional assays followed by in vivo experiments were implemented to evaluate the role of exosomes in mediating M2 macrophage polarization and LUAD progression. LUAD cells transmitted miR-3153 through exosomes. Heterogeneous nuclear ribonucleoprotein A2B1 (HNRNPA2B1) promoted miR-3153 biosynthesis and exosomal sorting. Exosomal miR-3153 targeted zinc finger protein 91 (ZFP91) to suppress the ubiquitination and degradation of misshapen-like kinase 1 (MINK1), thereby activating the c-Jun N-terminal kinase (JNK) signaling pathway and inducing M2 macrophage polarization. M2 macrophage polarization induced by LUAD cell-derived exosomes promoted the malignant process of LUAD cells. Transmission of exosomal miR-3153 by LUAD cells activates the JNK signaling pathway and induces M2 macrophage polarization, thus promoting the progression of LUAD.

Background Hepatocellular carcinoma (HCC) cell-derived exosomes have shown effects on inducing M2 macrophage polarization and promoting HCC progression. MiR-452-5p was reported by recent studies to promote malignancy progression as an exosomal microRNA that secreted by HCC cells, of which the underlying mechanism remains unclear. Here, we further explored how miR-452-5p functions in HCC. Methods MiR-452-5p expressions in HCC cells was examined by in situ hybridization. Next, HCC cell lines were transfected with the mimics or the inhibitor of miR-452-5p. Transfected cells' biological behavior were analyzed by CCK-8, flow cytometry, and Transwell assay. Then, exosomes were purified from miR-452-5p inhibited or overexpressed HCC cells and cocultured with macrophages to examine the role of miR-452-5p in macrophage polarization. To examine the role of exosomal miR-452-5p on macrophage polarization and tumor growth. We also performed the dual-luciferase assay to explore the targeting relationship between miR-452-5p and TIMP3. Results The upregulation of miR-452-5p was identified in HCC. The effects of HCC cell-derived exosomes on accelerating HCC migration and invasion and inducing M2 macrophage polarization were confirmed, which were further enhanced after overexpressing miR-452-5p but neutralized after silencing miR-452-5p. In addition, in vivo experiments demonstrated the effect of miR-452-5p on accelerating HCC growth and metastasis. Also, we identified that TIMP3 overexpression inhibited the promoted cell invasion and migration by HCC cell-derived exosomes. Conclusion Exosomal miR-452-5p secreted from HCC cells could induce polarization of M2 macrophage and therefore stimulating HCC progression by targeting TIMP3. Thus, miR-452-5p might be a potential biomarker for HCC prognosis.

Analysis of miR-203a-3p/SOCS3-mediated induction of M2 macrophage polarization to promote diabetic wound healing based on epidermal stem cell-derived exosomes

Gastric cancer (GC)-derived exosomes (Exos) have been identified to facilitate GC progression by inducing M2 macrophage polarization. This study investigated the biological function of exosomal matrilin-3 (MATN3) in M2 macrophage polarisation during GC development and its underlying mechanism. Exos were isolated from GC cells and then co-cultured with THP-1-derived macrophages. Macrophage polarisation was evaluated by measuring the levels of M1/M2 macrophage markers. Target molecule expression was evaluated by RT-qPCR, Western blotting and immunohistochemical staining. LC3II expression andthe co-localisationof MATN3 and epidermal growth factor receptor (EGFR) were determined by immunofluorescent staining. Invivo growth of GC cells was assessed in a xenograft mouse model. Molecular mechanisms were analysed by Co-IP, ChIP, dual-luciferase reporter assay and ubiquitination assay. MATN3 was highly expressed in GC and its high expression was negatively associated with the overall survival and M1 macrophage marker expression of GC patients. The invitro experiments validated that MATN3 was secreted by GC-Exos, which promoted M2 macrophage polarisation via autophagy activation. In addition, exosomal MATN3 contributed to invivo growth of GC cells via promoting M2 macrophage infiltration. Mechanistically, MATN3 interacted with EGFR to enhance its protein stability, which activated Ets-like protein-1 (ELK1) and consequently promoted ATG12-mediated autophagy. Activation of the EGFR/ELK1 pathway abolished exosomal MATN3 silencing-mediated inhibitory effect on autophagy and M2 macrophage polarisation. GC-derived exosomal MATN3 exerted an oncogenic role by inducing M2 macrophage polarisation via activation of the EGFR/ELK1/ATG12 axis-mediated autophagy, which provides potential therapeutic targets for GC.

Adenomyosis (AM), a gynecological disorder that severely affects female reproductive health. AM-associated macrophage (AAM) polarization-induced epithelial-mesenchymal transition (EMT) is a key driver of AM progression. In this study, we investigated the role and underlying mechanisms of endometrial mesenchymal stem cell (eMSC)-derived exosomes in regulating AAM polarization and the subsequent EMT of endometrial epithelial cells (EECs). In vitro coculture studies revealed that AM eutopic eMSCs markedly induced M2 macrophage polarization via exosomes and promoted EMT of EECs. Differentially expressed microRNAs (DE-miRNAs) between exosomes derived from normal eMSCs (N-eMSCs) and AM eutopic eMSCs (A-eMSCs) were identified using miRNA sequencing and miR-4669 was found to be the most significantly upregulated miRNA. Internalization of exosomal miR-4669 by macrophages induced their polarization toward the M2 phenotype and promoted the EMT of EECs. Mechanistic analysis using luciferase assay, mRNA sequencing, and rescue experiments revealed that miR-4669 induced M2 macrophage polarization via downregulation of DUSP6 and activation of MAPK/ERK signaling. The polarized M2 macrophages promoted the EMT of ISK cells via TGF-β1 secretion. In an AM xenograft mouse model, miR-4669 depletion inhibited AM progression by targeting the DUSP6/ERK1/2 pathway in macrophages. Overall, AM A-eMSC-derived exosomal miR-4669 facilitates M2 macrophage polarization by targeting the DUSP6/ERK signaling pathway, thereby promoting EMT of EECs via TGF-β1 secretion. These findings open avenues for developing novel preventive and therapeutic strategies for AM.

Norepinephrine stimulates M2 macrophage polarization via β2-adrenergic receptor-mediated IL-6 production in breast cancer cells

Oculomotor nerve injury impairs eye movement and pupil control. Intraorbital electroacupuncture (IEA) is a promising treatment, but its mechanisms remain unclear. This study investigates whether IEA promotes nerve recovery by inducing M2 macrophage polarization through the JAK1/STAT6 pathway. Sprague-Dawley (SD) rats with oculomotor nerve injury were divided into four groups: sham, control, IEA, and IEA + AS1517499 (JAK1/STAT6 inhibitor). Pupil diameter and abduction deviation were measured. Nerve structure was assessed with Luxol fast blue and Nissl staining. Western blotting analyzed JAK1/STAT6 pathway activation, and immunofluorescence quantified M1/M2 macrophages. The IEA group showed significant functional recovery in the oculomotor nerve, as evidenced by improvements in pupil diameter and abduction deviation compared to the control group. Histological analysis revealed better preservation of nerve structure in the IEA group, with reduced signs of damage. Western blot results demonstrated increased phosphorylation of STAT6 in the IEA group, indicating activation of the JAK1/STAT6 pathway. Immunofluorescence double staining revealed a higher ratio of M2 (CD206+, CD163+) macrophages relative to M1(CD86+ , iNOS+) macrophages in the IEA group. This effect was diminished in the IEA + AS1517499 group, suggesting that the therapeutic benefits of IEA are mediated through the JAK1/STAT6 pathway and M2 macrophage polarization. IEA promotes oculomotor nerve repair by inducing M2 macrophage polarization via the JAK1/STAT6 pathway, offering a potential therapeutic strategy for nerve injury.

Glioblastoma (GBM) cell-derived extracellular vesicles (EVs) have been demonstrated to modulate tumor microenvironment. In the present study, we attempted to discuss the role of hsa-microRNA-27a-3p (miR-27a-3p) delivered by GBM-EVs in M2 macrophage polarization. The isolated GBM-EVs were co-cultured with macrophages. After co-culture under normoxia/hypoxia, the effect of EV-derived hsa-miR-27a-3p on GBM cell biological processes was analyzed. Additionally, the target genes of hsa-miR-27a-3p were predicted. Moreover, the binding of enhancer of zeste homologue 1 (EZH1) to lysine-specific demethylase 3A (KDM3A) promoter region and the interaction between KDM3A and connective tissue growth factor (CTGF) were analyzed. GBM mouse models were established to verify the functions of EV-derived hsa-miR-27a-3p in vivo. We found increased hsa-miR-27a-3p in GBM tissues as well as GBM-EVs, which induced M2 polarization, thus promoting proliferative, migrative and invasive potentials of GBM cells. hsa-miR-27a-3p targeted EZH1 and promoted KDM3A expression to elevate the CTGF expression. GBM-EV-delivered hsa-miR-27a-3p promoted the KDM3A-upregulated CTGF by downregulating EZH1, thereby promoting M2 macrophage polarization and development of GBM in vivo. We demonstrated that EV-derived hsa-miR-27a-3p may promote M2 macrophage polarization to induce GBM.

We tried to unveil the clinical significance of miR-146a as a biomarker in M2 macrophage polarization in diabetic wound healing. Initially, we found reduced miR-146a in macrophages of diabetic patients. Next, dual-luciferase assay verified that toll-like receptor 4 (TLR4) was a target gene of miR-146 and was negatively regulated by miR-146. Moreover, after ectopic expression and depletion experiments of miR-146 and/or TLR4, lipopolysaccharide-induced inflammatory response of macrophages was detected. The results revealed that overexpression of miR-146a promoted the M2 macrophage polarization by suppressing the TLR4/nuclear factor-kappaB (NF-κB) axis, so as to enhance wound healing in diabetic ulcers. Further, mouse models with diabetic ulcers were established to investigate the effects of miR-146a on diabetic wound healing in vivo, which revealed that miR-146a promoted wound healing in diabetic ulcers by inhibiting the TLR4/NF-κB axis. In conclusion, we demonstrate that miR-146a can induce M2 macrophage polarization to enhance wound healing in diabetic ulcers by inhibiting the TLR4/NF-κB axis.

As a common digestive disease, acute pancreatitis (AP) often threatens the life of patients. Bone marrow mesenchymal stem cells (BMSCs) derived exosomes have exhibited some benefits for AP. However, the mechanism remains unclear and deserves to be further investigated. The characteristics of BMSCs-exosomes (BMSCs-Exos) were identified. The abundance of genes and proteins was evaluated using quantitative real-time PCR (RT-qPCR), western blot, enzyme-linked immunosorbent assay (ELISA) and IF assay. Cell apoptosis and CD206-positive cells were measured by flow cytometry. The interactions among miR-181a-5p, Zinc finger E-box binding homeobox2 (ZEB2) and Receptor for Activated C Kinase 1 (RACK1) were verified using dual luciferase reporter assay, RNA immunoprecipitation (RIP), coimmunoprecipitation (Co-IP). BMSCs-Exos effectively improved AP injury through restraining AR42J cell apoptosis and promoting M2 macrophage polarization, which was realized due to BMSCs-Exos harboring an abundance of miR-181a-5p. Further experiments validated miR-181a-5p silenced ZEB2 and ZEB2 reduced RACK1 expression through mediating RACK1 ubiquitination. ZEB2 knockdown decreased AR42J cell apoptosis and induced M2 macrophage polarization to alleviate AP injury, whereas RACK1 downregulation abolished these phenomena. BMSCs-Exos harboring miR-181a-5p suppressed AR42J cell apoptosis and promoted M2 macrophage polarization to delay AP progression through ZEB2-mediated RACK1 ubiquitination.

Colorectal cancer (CRC) is prone to metastasis, leading to a poor prognosis. miR-411-3p exhibits a tumor-suppressive function in CRC, but its exact mechanism is unclear. The malignant biological properties of CRC cells were detected by Carboxyfluorescein diacetate succinimidyl ester (CFSE) staining, scratch-wound and transwell assay. Levels of markers associated with macrophage polarization were evaluated by flow cytometry and ELISA kits. Bioinformatics analysis to screen whether the downstream target mRNA of miR-411-3p is matrix metalloproteinase 7 (MMP7), and Dual-Luciferase reporter assay verified the targeting relationship between the two. qRT-PCR tested miR-411-3p and MMP7 levels. MMP7 level was quantified by Western blot. Additionally, a nude mouse subcutaneous graft tumor model was constructed, Ki-67 expression was detected by immunohistochemistry, and the impact of miR-411-3p/MMP7 on the polarization of M2 macrophages was explored. miR-411-3p expression is downregulated in CRC. Knockdown of miR-411-3p elevated the amount of CFSE-positive, migrating, and invading cells, decreased apoptosis, and elevated the levels of M2 macrophage polarization markers. After overexpression of miR-411-3p, all of the above metrics were reversed in CRC cells. miR-411-3p targeted negative regulation of MMP7 expression, and MMP7 overexpression further enhanced the promotional effect of knockdown of miR-411-3p on the malignant progression of CRC and M2 macrophage polarization. Furthermore, knockdown of miR-411-3p upregulated the MMP7 level, elevated Ki-67-positive cells count, and induced M2 macrophage polarization in vivo. Knockdown of miR-411-3p upregulates MMP7 and induces M2 macrophage polarization, which in turn promotes malignant biological progression of CRC.

Introduction: Intermittent hypoxia (IH), an important feature of obstructive sleep apnea, enhances the function of lung cancer cell-derived extracellular vesicles (EVs) to exacerbate the immunosuppressive properties of macrophages. Herein, we investigated the effects of EVs obtained from lung adenocarcinoma cells cultured under IH on macrophage polarization. Methods: The M1-type and M2-type tumor-associated macrophages (TAMs) in tissues from lung adenocarcinoma cases with (n = 10) or without (n = 12) OSA were assessed by immunohistochemical studies. EVs obtained from A549 cells grown under normoxia (EV-NA) or IH (EV-IH) were isolated and cocultured with macrophages. MicroRNA sequencing was used to determine discrepant miRNAs in EVs, selecting miR-20a-5p for subsequent experiments. Next, reverse transcription-quantitative polymerase chain reaction, flow cytometry, luciferase reporter assay, western blotting assay, and gain- and loss-of-function assays were used to explore the mechanism by which miR-20a-5p promotes M2 macrophage polarization by targeting phosphatase and Tensin homolog gene (PTEN). Results: Stromal M2 TAMs were highly abundant in patients with lung adenocarcinoma and obstructive sleep apnea. Macrophages treated with EV-IH that highly expressed miR-20a-5p showed the M2 phenotype. Luciferase reporter assay confirmed PTEN as a target of miR-20a-5p. Transfection of miR-20a-5p mimics decreased PTEN expression, upregulated M2 polarization markers, and promoted Akt phosphorylation in macrophages, while transfection with a miR-20a-5p inhibitor had the opposite effects. Furthermore, miR-20a-5p inhibition in macrophages eliminated the PTEN downregulation, Akt phosphorylation, and upregulation of M2 polarization markers induced by EV-IH transfection.Conclusion: These findings indicate that EVs obtained from lung adenocarcinoma cells cultured under IH deliver miR-20a-5p to promote M2 macrophage polarization by targeting PTEN.

Liver metastasis is the primary cause of mortality in colorectal cancer (CRC) patients. To decipher the underlying mechanisms, we performed single-cell RNA sequencing (scRNA-seq) on paired primary colorectal tumors, adjacent tissues and liver metastases from three CRC liver metastasis (CRLM) patients, alongside colorectal tumors and adjacent tissues from three non-metastatic CRC patients. Our analysis revealed a significant enrichment of Enolase 2-expressing (ENO2⁺) cancer cells in CRLM patients compared to their non-metastatic counterparts. Functional characterization, supported by bioinformatics and murine models, demonstrated that ENO2⁺ cancer cells exhibit enhanced epithelial-mesenchymal transition (EMT) and are critical drivers of CRLM. Mechanistically, the ENO2 protein directly binds to macrophage migration inhibitory factor (MIF) within cancer cells, stabilizing MIF by inhibiting its C-terminus of Hsc70-Interacting Protein (CHIP)-mediated ubiquitination and degradation. This ENO2-MIF interaction activates MIF signaling, fostering robust tumor cell-macrophage crosstalk that promotes M2 macrophage polarization, which is validated by spatial transcriptomics showing the colocalization of ENO2⁺ cancer cells and M2 macrophages. Crucially, both organoid and in vivo models confirmed that ENO2 in CRC cells is essential for inducing M2 macrophage polarization via the MIF pathway, thereby facilitating liver metastasis. Knockout of ENO2 significantly suppressed tumor growth and liver metastasis in mouse models. An inhibitor of the ENO2-MIF interaction, pyrithioxin, can effectively reduce the burden of liver metastasis in mice. Collectively, our findings identify ENO2 as a key driver of CRLM by stabilizing MIF to orchestrate M2 macrophage polarization, highlighting the ENO2-MIF axis as a promising therapeutic strategy for CRLM.

Tumor-associated macrophages play a critical role in regulating the progression of lung adenocarcinoma (LUAD). Platelet-derived protein thrombospondin-2 (THBS2) has been identified as a tumor marker and is known to be overexpressed in LUAD. However, the specific role of THBS2 in M2 macrophage polarization within LUAD remains unclear. We conducted bioinformatics analyses to assess the clinical significance of THBS2 expression in LUAD, which was subsequently validated using quantitative PCR. We examined the relationship between THBS2 expression and M2 macrophage infiltration. A coculture system of LUAD cells and M0 macrophages was established to investigate the influence of THBS2 on macrophage infiltration and polarization through immunofluorescence and ELISA. We explored the impact of THBS2 on fatty acid metabolism (FAM) using oil red O staining and relevant kits and elucidated the role of THBS2 in regulating M2 macrophage polarization and LUAD proliferation through cell counting kit-8 (CCK-8) and colony formation assays. Western blot was employed to assess expression changes of Bax and Bcl-2. THBS2 was highly expressed in LUAD and was associated with poor prognosis in patients. In-vitro experiments demonstrated that silencing THBS2 significantly inhibited macrophage infiltration and polarization. THBS2 primarily activated FAM pathways, inducing M2 macrophage polarization and promoting LUAD cell proliferation. THBS2 enhanced LUAD proliferation by regulating FAM to induce M2 macrophage polarization. These findings provide a theoretical basis for targeting THBS2 as a novel therapeutic strategy in LUAD.

Ischemia-reperfusion injury (IRI) remains an unavoidable challenge in liver surgery, with macrophages playing a critical role in its pathogenesis. However, the mechanisms by which macrophages regulate the pathogenesis of IRI are not well understood. Through a target-guided screening approach, we identified a small 3 kDa peptide (SjDX5-271) from various schistosome egg-derived peptides that induced M2 macrophage polarization. SjDX5-271 treatment protected mice against liver IRI by promoting M2 macrophage polarization, and this protective effect was abrogated when the macrophages were depleted. Transcriptomic sequencing showed that the TLR signaling pathway was significantly inhibited in macrophages from the SjDX5-271 treatment group. We further identified that SjDX5-271 promoted M2 macrophage polarization by inhibiting the TLR4/MyD88/NF-κB signaling pathway and alleviated hepatic inflammation in liver IRI. Collectively, SjDX5-271 exhibited some promising therapeutic effects in IRI and represented a novel therapeutic approach, potentially applicable to other immune-related diseases. The current study demonstrates the potential of new biologics from the parasite, enhances our understanding of host-parasite interplay, and provides a blueprint for future therapies for immune-related diseases.