Induced M2 Macrophage Polarization Research Articles

Extracellular vesicle-packaged miR-4253 secreted by cancer-associated fibroblasts facilitates cell proliferation in gastric cancer by inducing macrophage M2 polarization

ABSTRACT Cancer-associated fibroblasts (CAFs) can interact with macrophages in the tumor microenvironment by secreting extracellular vesicles (EVs), thereby affecting tumor progression. However, the mechanisms of CAF-secreted EVs in gastric cancer (GC) remain not well understood. Here, we investigated the effect of CAF-EVs on macrophage polarization in GC and the underlying mechanisms. Macrophage polarization was evaluated using flow cytometry and quantitative real-time polymerase chain reaction. GC cell proliferation was determined using cell counting kit-8, EdU, and colony formation assays. The molecular mechanism was explored using microarray analysis, dual-luciferase reporter assay, and RNA pull-down analysis. The results showed that CAFs secreted EVs that inhibit macrophage M1 polarization and promote M2 polarization. Moreover, miR-4253 expression was increased in CAF-EVs, and inhibition of miR-4253 reversed the macrophage polarization induced by EVs. IL6R was identified as the target of miR-4253. Additionally, macrophages treated with EVs that encapsulated miR-4253 promote GC cell proliferation. In conclusion, CAF-secreted EVs packaging miR-4253 facilitate macrophage polarization from M1 to M2 phenotype by targeting IL6R, thereby accelerating GC cell proliferation. The findings suggest that EV-encapsulated miR-4253 may be a promising therapeutic target of GC.

Paricalcitol ameliorates diabetic nephropathy by promoting EETs and M2 macrophage polarization and inhibiting inflammation by regulating VDR/CYP2J2 axis.

Previous studies have shown that paricalcitol (PA) has a protective effect on the kidneys. However, the exact molecular mechanism by which PA affects diabetic nephropathy (DN) progression remains uncertain. PBMCs of patients with DN were isolated, and CYP2J2 and VDR levels were detected by qPCR. Pearson correlation analysis was utilized to detect the relationship between uACR and CYP2J2 and VDR and between CYP2J2 and VDR. The protective effects of PA on DN have been examined by TUNEL, HE staining, ELISA, and Flow cytometry assays in STZ-induced mice. Moreover, THP-1 cells were stimulated with HG/LPS for invitro studies. ELISA, qPCR, western blot, and Flow cytometry assays were utilized to assess the effects of PA on DN progression by regulating CYP2J2. The interaction between CYP2J2 and VDR was analyzed by CHIP-qPCR and luciferase experiments. CYP2J2 and VDR levels were downregulated and uACR level was upregulated in DN patients. CYP2J2 and VDR were positively correlated in PBMCs. Both CYP2J2 and VDR are inversely correlated with uACR. Moreover, after PA treatment, 11, 12-EET levels increased, inflammatory factor levels decreased, and M2 macrophage polarization was promoted in STZ-induced mice and HG/LPS-triggered THP-1 cells. Depletion of CYP2J2 and VDR decreased 11, 12-EET level, enhanced inflammatory factor levels, and inhibited M2 macrophage polarization, which were reversed by CYP2J2 overexpression in HG/LPS-treated cells. Furthermore, VDR bound to the CYP2J2 promoter and promoted CYP2J2 transcriptional expression. The present work pointed out a new use for PA to inhibit DN progression by increasing EET level, inhibiting inflammatory response, and inducing M2 macrophage polarization via regulating the VDR/CYP2J2 axis.

IL-17RA/CTSK axis mediates H. pylori-induced castration-resistant prostate cancer growth.

In this investigation, we explored the molecular dynamics guiding the progression of castration-resistant prostate cancer (CRPC) influenced by Helicobacter pylori (H. pylori)-mediated M2 polarization of macrophages through the IL-17RA/CTSK/EMT axis. An 830-patient clinical trial categorized subjects into hormone-sensitive prostate cancer (HSPC) and CRPC groups. H. pylori infection, evaluated by ELISA, exhibited a higher incidence in CRPC patients, impacting overall survival (OS) and progression-free survival. In-depth in vitro and in vivo experiments, including 16S rDNA sequencing, immunohistochemical tests, and transcriptome analysis, unveiled that H. pylori promotes CRPC growth and metastasis by upregulating IL-17RA and CTSK, leading to enhanced EMT. Notably, M2 macrophages emerged as pivotal immune cells influencing CRPC progression. This study uncovers a novel pathway wherein H. pylori enrichment exacerbates CRPC by inducing macrophage M2 polarization, IL-17RA/CTSK expression, and EMT activation, shedding light on a previously unrecognized mechanism contributing to the growth and metastasis of CRPC.

Exosomal miR-106a-5p from highly metastatic colorectal cancer cells drives liver metastasis by inducing macrophage M2 polarization in the tumor microenvironment

BackgroundThe tumor microenvironment (TME) is a dynamic system orchestrated by intricate cell-to-cell crosstalk. Specifically, macrophages within the TME play a crucial role in driving tumor progression. Exosomes are key mediators of communication between tumor cells and the TME. However, the mechanisms underlying exosome-driven crosstalk between tumor cells and macrophages during colorectal cancer (CRC) progression remain incompletely elucidated.MethodsSingle-cell RNA sequencing were analyzed using the Seurat package. Exosomes were isolated using ultracentrifugation and characterized by transmission electron microscopy, nanoparticle tracking analysis, and western blot. miRNAs differentially expressed in exosomes were analyzed using the limma package. CD206 expression in CRC tissues, exosomes tracing, and exosomal miR-106a-5p transport were observed through immunofluorescence. Macrophage polarization was assessed via qRT-PCR, ELISA, and flow cytometry. The interactions between miR-106a-5p, hnRNPA1, and SOCS6 were evaluated using miRNA pull-down, RIP, and dual-luciferase reporter assays. Transwell assays and liver metastasis model explored the role of exosomal miR-106a-5p-induced M2 macrophages in promoting CRC liver metastasis.ResultThe proportion of M2 macrophages is increased in CRC with liver metastasis compared to those without. Highly metastatic CRC cells release exosomes enriched with miR-106a-5p, which promote macrophages M2 polarization by suppressing SOCS6 and activating JAK2/STAT3 pathway. These M2 macrophages reciprocally enhance CRC liver metastasis. hnRNPA1 regulate the transport of miR-106a-5p into exosomes. Clinically, elevated miR-106a-5p in plasma exosomes correlated with liver metastasis and poor prognosis.ConclusionCRC-derived exosomal miR-106a-5p plays a critical role in promoting liver metastasis and is a potential biomarker for the prevention and treatment of CRC liver metastasis.

Immune-response gene 1 deficiency aggravates inflammation-triggered cardiac dysfunction by inducing M1 macrophage polarization and aggravating Ly6Chigh monocyte recruitment

The immune response gene 1 (IRG1) and its metabolite itaconate are implicated in modulating inflammation and oxidative stress, with potential relevance to sepsis-induced myocardial dysfunction (SIMD). This study investigates their roles in SIMD using both in vivo and in vitro models. Mice were subjected to lipopolysaccharide (LPS)-induced sepsis, and cardiac function was assessed in IRG1 knockout (IRG1-/-) and wild-type mice. Exogenous 4-octyl itaconate (4-OI) supplementation was also examined for its protective effects. In vitro, bone marrow-derived macrophages and RAW264.7 cells were treated with 4-OI following Nuclear factor, erythroid 2 like 2 (NRF2)–small interfering RNA administration to elucidate the underlying mechanisms. Our results indicate that IRG1 deficiency exacerbates myocardial injury during sepsis, while 4-OI administration preserves cardiac function and reduces inflammation. Mechanistic insights reveal that 4-OI activates the NRF2/HO-1 pathway, promoting macrophage polarization and attenuating inflammation. These findings underscore the protective role of the IRG1/itaconate axis in SIMD and suggest a therapeutic potential for 4-OI in modulating macrophage responses.

The magnesium-doped CSH/BCP promotes alveolar bone regeneration by mediating M2 macrophage polarization via miR-21–5p/Smad2 axis

The repair of alveolar bone defects is a complex biological process that involves the interplay between implant materials, bone marrow mesenchymal stem cells (BMSCs), and the immune cells present in the surrounding area. Moreover, the polarization of macrophages induced by implant materials has been shown to play a crucial role in regulating bone regeneration. Recent studies have discovered that M2 macrophages promote the osteogenic differentiation of BMSCs by activating the TGF-β/BMP signaling pathway. However, the molecular mechanisms underlying the regulation of bone regeneration in BMSCs by macrophages remain unclear. Our in vivo study demonstrated that a 10 % magnesium (Mg2+)-doped calcium sulfate hemihydrate -biphasic calcium phosphate (CSH/BCP) composite ceramic material was effective in repairing alveolar bone defects in rabbits. In our in vitro study, we observed that this ceramic material could induce M2 macrophage polarization and reduce inflammation. Moreover, the conditioned media obtained from M2 macrophages promoted the osteogenic differentiation of BMSCs. Additionally, our research showed that overexpression of miR-21–5p inhibited M2 macrophage polarization and reduced the osteogenic differentiation capacity of BMSCs. Co-overexpression of miR-21–5p and Smad2 in macrophages partially reversed the effects of miR-21–5p on the osteogenic differentiation of BMSCs and macrophage polarization. These findings suggested that Mg2+-doped CSH/BCP composite ceramic materials could enhance M2 macrophage polarization through the miR-21–5p/Smad2 axis, and the microenvironment of M2 macrophages could further promote the osteogenic differentiation of BMSCs. The findings presented in this work offer valuable insights into the molecular mechanisms that regulate bone regeneration in BMSCs and the role of macrophages in this process.

Anti-inflammatory effects of MerTK by inducing M2 macrophage polarization via PI3K/Akt/GSK-3β pathway in gout

Mer tyrosine kinase (MerTK) has been found to regulate the secretion of inflammatory factors and exert immunosuppressive effects, but its role in gout remains unclear. In this study, we aimed to clarify the immnue effects of MerTK in gout. MerTK in synovium or serum of gout patients was determined by immunohistochemistry, enzyme-linked immunosorbent assay (ELISA), and real-time quantitative polymerase chain reaction (RT-qPCR). In monosodium urate (MSU)-induced gout mice, the effect of MerTK inhibitor (UNC2250) on inflammation and polarization was also assessed. After inhibition, knockdown or overexpression of MerTK, inflammatory response and polarization level in THP1-derived macrophages were evaluated by RT-qPCR and flow cytometry. Regulation of MerTK inhibitors on mitochondrial function and downstream pathway in THP1-derived macrophages were detected. MerTK in synovium and serum of gout patients were increased. MerTK inhibitor stimulated the inflammation and M1 polarization in MSU-induced gout mice. MerTK inhibition, knock-down, or overexpression affected inflammatory response, polarization and mitochondrial function in vitro in gout model. The PI3K/Akt/GSK-3β pathway was identified to reduce after MerTK inhibition and the relevant results were as expected, validated by knock-down or overexpressing MerTK. In conclusion, MerTK was detected to increase in both gout patients and model. MerTK influenced inflammatory response and polarization markers through PI3K/Akt/GSK-3β pathway. Interfering MerTK/PI3K/Akt/GSK-3β axis may provide a new therapeutic target for gout.

The Nf1-Q181X point mutation induces M2 macrophage polarization via the AKT/STAT pathway to promote smooth muscle cell proliferation and migration.

Increased case reports have shown that patients with NF1 have an increased risk of extensive vascular vasculopathy. Previous studies demonstrated the presence of macrophages and smooth muscle cells in the neoplastic intima of carotid arteries after injury in Nf1+/- mice. However, whether NF1 gene mutations affect macrophage polarization and macrophage-smooth muscle cell interactions remains to be elucidated. Scratch assay and transwell assay were utilized to detect cell migration ability. The dye 2',7'dichlorofluorescin diacetate and neutral red stain were used to assess intracellular ROS production and cell phagocytosis function, respectively. Proteins and mRNA expression were determined by western blot, RT-qPCR, and immunofluorescence. Finally, the macrophage (MAC) and vascular smooth muscle cell (VSMC) co-culture system was used to detect cellular crosstalk. Cell function assays confirmed that the Nf1-Q181X point mutation attenuated the phagocytosis of bone marrow-derived macrophages (BMDMs) and promoted the migration and ROS production of BMDMs. Moreover, we found that the Nf1-Q181X point mutation inhibited M1 but promoted M2 macrophage polarization by down-regulating p38, ERK, and JNK and up-regulating the Akt/STAT3 signaling pathway, respectively. Furthermore, in the MAC-VSMC co-culture system, we demonstrated that Nf1-Q181X point mutation-activated M2 BMDMs promoted proliferation and migration of VSMCs and induced the transformation of VSMCs from contractile phenotype to synthetic phenotype. The findings suggest that the Nf1-Q181X point mutation can mediate macrophage polarization and promote smooth muscle cell proliferation and migration, providing clinical clues for the treatment of NF1-complicated vasculopathy.

Exosomal LINC00958 maintains ovarian cancer cell stemness and induces M2 macrophage polarization via Hedgehog signaling pathway and GLI1 protein

Long non-coding RNA (lncRNA) LINC00958 has been reported to promote many gynecological cancers, but its detailed function in OC remains unclear. Cancer stem cells (CSCs) and tumor-associated macrophages (TAMs) have been reported to participate in the occurrence and metastasis of cancers. We want to explore the effects of exosomal LINC00958 on cell stemness and macrophage polarization in OC. LINC00958 expression was first verified in OC cells and its function on cell stemness was verified by subcellular fractionation analysis, sphere formation assay and so on. Exosomal LINC00958 was secreted from OC cells and the model of M2 macrophage polarization was established to further verify the impact of exosomal LINC00958 on the cell stemness and macrophage polarization of OC cells using several mechanism experiments including flow cytometry, RNA pulldown, luciferase reporter assays and so on. LINC00958 was up-regulated in OC cells and exosomal LINC00958 enhanced the stem cell-like properties of OC cells and M2 macrophage polarization. Furthermore, LINC00958 combined with glioma-associated oncogene homolog 1 (GLI1) to activate Hedgehog pathway, thereby promoting M2 polarization. Exosomal LINC00958 maintained OC cell stemness and induced M2 polarization via the Hedgehog signaling pathway.

Sciatic nerve stimulation alleviates neuropathic pain and associated neuroinflammation in the dorsal root ganglia in a rodent model

BackgroundSatellite glial cells (SGCs) in the dorsal root ganglia (DRG) play a pivotal role in the formation of neuropathic pain (NP). Sciatic nerve stimulation (SNS) neuromodulation was reported to alleviate NP and reduce neuroinflammation. However, the mechanisms underlying SNS in the DRG remain unclear. This study aimed to elucidate the mechanism of electric stimulation in reducing NP, focusing on the DRG.MethodsL5 nerve root ligation (NRL) NP rat model was studied. Ipsilateral SNS performed 1 day after NRL. Behavioral tests were performed to assess pain phenotypes. NanoString Ncounter technology was used to explore the differentially expressed genes and cellular pathways. Activated SGCs were characterized in vivo and in vitro. The histochemical alterations of SGCs, macrophages, and neurons in DRG were examined in vivo on post-injury day 8.ResultsNRL induced NP behaviors including decreased pain threshold and latency on von Frey and Hargreaves tests. We found that following nerve injury, SGCs were hyperactivated, neurotoxic and had increased expression of NP-related ion channels including TRPA1, Cx43, and SGC-neuron gap junctions. Mechanistically, nerve injury induced reciprocal activation of SGCs and M1 macrophages via cytokines including IL-6, CCL3, and TNF-α mediated by the HIF-1α-NF-κB pathways. SNS suppressed SGC hyperactivation, reduced the expression of NP-related ion channels, and induced M2 macrophage polarization, thereby alleviating NP and associated neuroinflammation in the DRG.ConclusionsNRL induced hyperactivation of SGCs, which had increased expression of NP-related ion channels. Reciprocal activation of SGCs and M1 macrophages surrounding the primary sensory neurons was mediated by the HIF-1α and NF-κB pathways. SNS suppressed SGC hyperactivation and skewed M1 macrophage towards M2. Our findings establish SGC activation as a crucial pathomechanism in the gliopathic alterations in NP, which can be modulated by SNS neuromodulation.

Upregulation of MELK promotes chemoresistance and induces macrophage M2 polarization via CSF-1/JAK2/STAT3 pathway in gastric cancer

BackgroundGastric cancer (GC) stands out as one of the most prevalent malignancies affecting the digestive system, characterized by a substantial incidence rate and mortality. Maternal embryonic leucine zipper kinase (MELK) has been implicated in the advancement of various cancer types and the modulation of the tumor microenvironment. This study aims to delve into the involvement of MELK in chemoresistance and the tumor microenvironment of GC.MethodsThe MELK expression was detected using quantitative real-time polymerase chain reaction (qRT-PCR), western blotting and immunohistochemistry. Lentiviral transfection was employed to establish stable cell lines with either overexpressed or silenced MELK. The impact of MELK on the chemoresistance of GC cells and the polarization of macrophages was investigated through in vitro and in vivo functional assays. Additionally, the correlation between MELK and the cytokines colony-stimulating factor 1 (CSF-1), as well as stromal macrophages, was analysed. The prognostic significance of MELK, CSF-1, and CD206 expression levels in clinical samples was further investigated.ResultsMELK was found to be highly expressed in chemoresistant GC cells and tissues. Furthermore, both in vitro and in vivo assays indicated that MELK overexpression conferred chemoresistance in GC cells. Additionally, MELK overexpression was observed to induce M2 macrophage polarization via the CSF-1/JAK2/STAT3 pathway, thereby contributing to chemoresistance within the tumor microenvironment. The expression of MELK in GC tissues from neoadjuvant chemotherapy patients correlated positively with CSF-1 and CD206. Moreover, patients with higher expression levels of MELK, CSF-1, or CD206 exhibited significantly shorter OS and DFS rates.ConclusionsOur investigation underscores the critical role of MELK in promoting chemoresistance and inducing M2 macrophage polarization in GC. It proposes novel targets and methods for the treatment of GC, as well as prognostic factors for neoadjuvant chemotherapy.

Gastric cancer cell-derived exosomal miR-541-5p induces M2 macrophage polarization through DUSP3/JAK2/STAT3 pathway

PurposeExosomal microRNAs have been identified as important mediators of communication between tumor cells and macrophages in the microenvironment. miR-541-5p was reported to be involved in hepatocellular carcinoma progression, but its role in gastric cancer (GC) and in GC cell-macrophage crosstalk is unknown.MethodsCell proliferation, migration and invasion were respectively assessed by CCK-8 assay, scratch and Transwell assays. RT-qPCR was used to detect the level of miR-541-5p, macrophage markers and DUSP3. The percentage of CD11b+CD206+ cell population was analyzed by flow cytometry. Western blotting was employed to evaluate DUSP3-JAK2/STAT3 pathway proteins and exosome markers. The interaction between miR-541-5p and DUSP3 was verified by luciferase assay.ResultsThe results showed that miR-541-5p was upregulated in GC tissues and cells, and stimulated GC cell growth, migration and invasion in vitro. GC cells induce M2 macrophage polarization by secreting the exosomal miR-541-5p. Exosomal miR-541-5p maintained JAK2/STAT3 pathway activation in macrophages by targeting negative regulation of DUSP3. Inhibiting miR-541-5p significantly limited tumor growth in vivo.ConclusionIn conclusion, miR-541-5p promotes GC cell progression. GC cells may induce macrophage M2 polarization through the exosomal miR-541-5p-mediated DUSP3/JAK2/STAT3 pathway. miR-541-5p may be a potential therapeutic target for GC.

Depletion of essential mycobacterial gene glmM reduces pathogen survival and induces host-protective immune responses against tuberculosis

The limitations of TB treatment are the long duration and immune-dampening effects of anti-tuberculosis therapy. The Cell wall plays a crucial role in survival and virulence; hence, enzymes involved in its biosynthesis are good therapeutic targets. Here, we identify Mycobacterium tuberculosis (Mtb) GlmM, (GlmMMtb) engaged in the UDP-GlcNAc synthesis pathway as an essential enzyme. We generated a conditional knockdown strain, Rv-glmMkD using the CRISPR interference-mediated gene silencing approach. Depletion of GlmMMtb affects the morphology and thickness of the cell wall. The Rv-glmMkD strain attenuated Mtb survival in vitro, in the host macrophages (ex vivo), and in a murine mice infection model (in vivo). Results suggest that the depletion of GlmMMtb induces M1 macrophage polarization, prompting a pro-inflammatory cytokine response, apparent from the upregulation of activation markers, including IFNɣ and IL-17 that resists the growth of Mtb. These observations provide a rationale for exploring GlmMMtb as a potential therapeutic target.

Prostate cancer–induced endothelial-cell-to-osteoblast transition drives immunosuppression in the bone–tumor microenvironment through Wnt pathway–induced M2 macrophage polarization

Immune checkpoint therapy has limited efficacy for patients with bone-metastatic castration-resistant prostate cancer (bmCRPC). To improve immunotherapy for bmCRPC, we aimed to identify the mechanism of bmCRPC-induced changes in the immune microenvironment. Among bmCRPC patients, higher levels of a 32-gene M2-like macrophage signature in bone metastasis samples correlated with shorter overall survival. Immunohistochemistry showed that CD206-positive (CD206+) macrophages were enriched in bmCRPC bone biopsy specimens compared with primary tumors or lymph node metastases. In preclinical osteogenic prostate cancer (Pca) xenograft models, CD206+ macrophages were recruited to areas with tumor-induced bone. RNA sequencing (RNAseq) analysis showed higher expression of an M2-like gene signature, with activated canonical and noncanonical Wnt pathways, in tumor-associated macrophages isolated from osteogenic tumors (bone-TAMs) than in TAMs isolated from nonosteogenic tumors (ctrl-TAMs). Mechanistic studies showed that endothelial cells (ECs) that had undergone EC-to-osteoblast (EC-to-OSB) transition, the precursors of tumor-induced OSBs, produced paracrine factors, including Wnts, CXCL14, and lysyl oxidase, which induced M2 polarization and recruited M2-like TAMs to the bone-tumor microenvironment (bone-TME). Bone-TAMs suppressed CD8+ T cells' proliferation and cytolytic activity, and these effects were partially reversed by treating bone-TAMs with Wnt inhibitors. Genetic or pharmacological inhibition of Pca-induced EC-to-OSB transition reduced the levels of M2-like macrophages in osteogenic tumors. Our study demonstrates that Pca-induced EC-to-OSB transition drives immunosuppression in the bone-TME, suggesting that therapies that reduce Pca-induced bone formation may improve immunotherapeutic outcomes for bmCRPC.

Implantable Zinc Ion Battery and Osteogenesis-Immunoregulation Bifunction of Its Catabolite.

Biocompatible batteries can power implantable electronic devices and have broad applications in medicine. However, the controlled degradation of implantable batteries, the impact of battery catabolites on surrounding tissues, and wireless charging designs are often overlooked. Here, we designed an implantable zinc ion battery (ZIB) using a gelatin/polycaprolactone-based composite gel electrolyte. The prepared ZIBs deliver a high specific capacity of 244.0 mA h g-1 (0.5C) and long cycling stability of 300 cycles (4C). ZIBs were completely degraded within 8 weeks in rats and 30 days in a phosphate-buffered saline lipase solution, demonstrating good biocompatibility and degradability. ZIBs catabolites induced macrophage M2 polarization and exhibited anti-inflammatory properties, with mRNA levels of the M2 markers Arg-1 and CD206 up-regulated 15.8-fold and 13.4-fold, respectively, compared to the blank control group. Meanwhile, the expressions of two typical osteogenic markers, osteopontin and osteocalcin, were up-regulated by 3.6-fold and 5.6-fold, respectively, demonstrating that designed ZIBs promoted osteogenic differentiation of bone marrow mesenchymal stem cells. Additionally, a wireless energy transmission module was designed using 3D printing technology to realize real-time charging of the ZIB in rats. The designed ZIB is a promising power source for implantable medical electronic devices and also serves as a functional material to accelerate bone repair.

Zhiqiao Gancao decoction regulated JAK2/STAT3/ macrophage M1 polarization to ameliorate intervertebral disc degeneration

BackgroundZhiqiao Gancao decoction (ZQGCD) was created by Professor Gong Zhengfeng, a renowned Chinese medicine expert. Clinical studies have shown its efficacy in alleviating pain and enhancing lumbar function in intervertebral disc degeneration (IDD) patients. However, the precise mechanism of ZQGCD in treating IDD remains unclear. MethodsThe active components of ZQGCD were identified using Liquid chromatography-tandem mass spectrometry (LC-MS/MS). A rat model of intervertebral disc degeneration was established, and rats in each group received ZQGCD for three weeks. Assessment parameters included hyperalgesia status, observation of intervertebral disc tissue degeneration and macrophage infiltration, and analysis of JAK2/STAT3 pathway protein expression in the intervertebral disc. Primary macrophage M1 polarization was induced using LPS, with cells treated using the JAK2 inhibitor (AZD1480) and ZQGCD to evaluate macrophage polarization, cellular supernatant inflammatory factors, and JAK2/STAT3 pathway expression. Macrophage supernatant served as a conditioned medium to observe its effects on the proliferation of nucleus pulposus cells (NPCs) and the expression of collagen II and MMP3 proteins. ResultsA total of 81 active components were identified in ZQGCD. Following ZQGCD treatment, infiltrating macrophages in intervertebral disc tissues of model rats decreased, the content of M1 macrophages decreased, while the content of M2 macrophages increased, the expression of proinflammatory factors and pain-inducing factors in serum decreased, and the expression of substance P in intervertebral disc tissue decreased. Consequently, the intervertebral disc degeneration and hyperalgesia of rats were improved. In vitro studies revealed that LPS induced M1 macrophage polarization. By inhibiting the JAK2/STAT3 pathway, both JAK2 inhibitors and ZQGCD effectively suppressed M1 polarization, resulting in decreased levels of IL-1β, IL-6, TNF-α, and various other inflammatory factors. Consequently, this inhibition led to a delay in the degeneration of NPCs. ConclusionThere is macrophage infiltration in the intervertebral disc tissue of IDD rats, and JAK2/STAT3 pathway is activated, macrophages are polarized to M1 type, resulting in inflammatory microenvironment, leading to intervertebral disc degeneration and hyperalgesia. ZQGCD exhibited a delaying effect on IDD and improved hyperalgesia by inhibiting the JAK2/STAT3/macrophage M1 polarization pathway.

Hypoxia conduces the glioma progression by inducing M2 macrophage polarization via elevating TNFSF9 level in a histone-lactylation-dependent manner.

Hypoxia is a critical factor contributing to a poor prognosis and challenging glioma therapy. Previous studies have indicated that hypoxia drives M2 polarization of macrophages and promotes cancer progression in various solid tumors. However, the more complex and diverse mechanisms underlying this process remain to be elucidated. Here, we aimed to examine the functions of hypoxia in gliomas and preliminarily investigate the underlying mechanisms of M2 macrophage polarization caused by hypoxia. We found that hypoxia significantly enhances the malignant phenotypes of U87 and U251 cells by regulating glycolysis. In addition, hypoxia mediated accumulation of the glycolysis product [lactic acid (LA)], which is subsequently absorbed by macrophages to induce its M2 polarization, and this process is reverted by both the glycolysis inhibitor and silenced monocarboxylate transporter (MCT-1) in macrophages, indicating that M2 macrophage polarization is associated with the promotion of glycolysis by hypoxia. Interestingly, we also found that hypoxia mediated LA accumulation in glioma cells upon uptake by macrophages upregulates H3K18La expression and promotes tumor necrosis factor superfamily member 9 (TNFSF9) expression in a histone-lactylation-dependent manner based on the results of chromatin immunoprecipitation sequencing (ChIP seq) enrichment analysis. Subsequent in vitro and in vivo experiments further indicated that TNFSF9 facilitated glioma progression. Mechanistically, hypoxia-mediated LA accumulation in glioma cells is taken up by macrophages and then induces its M2 macrophage polarization by regulating TNFSF9 expression via MCT-1/H3K18La signaling, thus facilitating the malignant progression of gliomas.NEW & NOTEWORTHY Our study revealed that hypoxia induces the production of LA accumulation through glycolysis in glioma cells, which is subsequently absorbed by macrophages and leads to its M2 polarization via the MCT-1/H3K18La/TNFSF9 axis, ultimately significantly promoting the malignant progression of glioma cells. These findings are novel and noteworthy as they provide insights into the connection between energy metabolism and epigenetics in gliomas.

Rab11b promotes M1-like macrophage polarization by restraining autophagic degradation of NLRP3 in alcohol-associated liver disease.

Macrophage polarization is vital to mounting a host defense or repairing tissue in various liver diseases. Excessive activation of the NLR family pyrin domain containing 3 (NLRP3) inflammasome is related to the orchestration of inflammation and alcohol-associated liver disease (ALD) pathology. Rab GTPases play critical roles in regulating vesicular transport. In this study we investigated the role of Rab11b in ALD, aiming to identify effective therapeutic targets. Here, we first demonstrated a decreased expression of Rab11b in macrophages from ALD mice. Knockdown of Rab11b by macrophage-specific adeno-associated virus can alleviate alcohol induced liver inflammation, injury and steatosis. We found that LPS and alcohol stimulation promoted Rab11b transferring from the nucleus to the cytoplasm in bone marrow-derived macrophages (BMDM) cells. Rab11b specifically activated the NLRP3 inflammasome in BMDMs and RAW264.7 cells to induce M1 macrophage polarization. Rab11b overexpression in BMDMs inhibited autophagic flux, leading to the suppression of LC3B-mediated NLRP3 degradation. We conclude that impaired Rab11b could alleviate alcohol-induced liver injury via autophagy-mediated NLRP3 degradation.

A Janus Microsphere Delivery System Orchestrates Immunomodulation and Osteoinduction by Fine-tuning Release Profiles.

Bone regeneration is a well-orchestrated process synergistically involving inflammation, angiogenesis, and osteogenesis. Therefore, an effective bone graft should be designed to target multiple molecular events and biological demands during the bone healing process. In this study, a biodegradable gelatin methacryloyl (GelMA)-based Janus microsphere delivery system containing calcium phosphate oligomer (CPO) and bone morphogenetic protein-2 (BMP-2) is developed based on natural biological events. The exceptional adjustability of GelMA facilitates the controlled release and on-demand application of biomolecules, and optimized delivery profiles of CPO and BMP-2 are explored. The sustained release of CPO during the initial healing stages contributes to early immunomodulation and promotes mineralization in the late stage. Meanwhile, the administration of BMP-2 at a relatively high concentration within the therapeutic range enhances the osteoinductive property. This delivery system, with fine-tuned release patterns, induces M2 macrophage polarization and creates a conducive immuno-microenvironment, which in turn facilitates effective bone regeneration in vivo. Collectively, this study proposes a bottom-up concept, aiming to develop a user-friendly and easily controlled delivery system targeting individual biological events, which may offer a new perspective on developing function-optimized biomaterials for clinical use.

MiR-455/GREM1 axis promotes colorectal cancer progression and liver metastasis by affecting PI3K/AKT pathway and inducing M2 macrophage polarization

BackgroundColorectal cancer is among the most common malignant tumors affecting the gastrointestinal tract. Liver metastases, a complication present in approximately 50% of colorectal cancer patients, are a considerable concern. Recently, studies have revealed the crucial role of miR-455 in tumor pathogenesis. However, the effect of miR-455 on the progression of liver metastases in colorectal cancer remains controversial. As an antagonist of bone morphogenetic protein(BMP), Gremlin 1 (GREM1) may impact organogenesis, body patterning, and tissue differentiation. Nevertheless, the role of miR-455 in regulating GREM1 in colorectal cancer liver metastases and how miR-455/GREM1 axis influences tumour immune microenvironment is unclear.MethodsBioinformatics analysis shows that miR-455/GREM1 axis plays crucial role in liver metastasis of intestinal cancer and predicts its possible mechanism. To investigate the impact of miR-455/GREM1 axis on the proliferation, invasion, and migration of colorectal cancer cells, colony formation assay, wound healing and transwell assay were examined in vitro. The Dual-Luciferase reporter gene assay and RNA pull-down assay confirmed a possible regulatory effect between miR-455 and GREM1. In vivo, colorectal cancer liver metastasis(CRLM) model mice was established to inquiry the effect of miR-455/GREM1 axis on tumor growth and macrophage polarization. The marker of macrophage polarization was tested using immunofluorescence(IF) and quantitative real-time polymerase chain reaction(qRT-PCR). By enzyme-linked immunosorbent assay (ELISA), cytokines were detected in culture medium supernatants.ResultsWe found that miR-455 and BMP6 expression was increased and GREM1 expression was decreased in liver metastase compared with primary tumor. miR-455/GREM1 axis promotes colorectal cancer cells proliferation, migration, invasion via affected PI3K/AKT pathway. Moreover, downregulating GREM1 augmented BMP6 expression in MC38 cell lines, inducing M2 polarization of macrophages, and promoting liver metastasis growth in CRLM model mice.ConclusionThese data suggest that miR-455/GREM1 axis promotes colorectal cancer progression and liver metastasis by affecting PI3K/AKT pathway and inducing M2 macrophage polarization. These results offer valuable insights and direction for future research and treatment of CRLM.