Promoting M2 Macrophage Polarization Research Articles

Lycopene promoted M2 macrophage polarization via inhibition of NOTCH1-PI3K-mTOR-NF-κB-JMJD3-IRF4 pathway in response to Escherichia coli infection in J744A.1 cells.

Escherichia coli (E. coli) can induce severe clinical bovine mastitis, which is to blame for large losses experienced by dairy farms. Macrophage polarization into various states is in response to pathogen infections. Lycopene, a naturally occurring hydrocarbon carotenoid, relieved inflammation by controlling M1/M2 status of macrophages. Thus, we wanted to explore the effect of lycopene on polarization states of macrophages in E. coli-induced mastitis. Macrophages were cultivated with lycopene for 24, before E. coli inoculation for 6h. Lycopene (0.5μmol/L) significantly enhanced cell viabilities and significantly reduced lactic dehydrogenase (LDH) levels in macrophages, whereas 2 and 3μmol/L lycopene significantly enhanced LDH activities. Lycopene treatment significantly reduced the increase in LDH release, iNOS, CD86, TNF-α, IL-1β and phosphatase and tensin homolog (PTEN) expressions in E. coli group. 0.5μmol/L lycopene significantly increased E. coli-induced downregulation of CD206, arginase I (ARG1), indoleamine 2,3-dioxygenase (IDO), chitinase 3-like 3 (YM1), PI3K, AKT, p-AKT, mammalian target of rapamycin (mTOR), p-mTOR, jumonji domain-containing protein-3 (JMJD3) and interferon regulatory factor 4 (IRF4) levels. Moreover, Ginkgolic acid C17:1 (a specific PTEN inhibitor), 740YPDGFR (a specific PI3K activator), SC79 (a specific AKT activator) or CHPG sodium salt (a specific NF-κB activator) significantly decreased CD206, AGR1, IDO and YM1 expressions in lycopene and E. coli-treated macrophages. Therefore, lycopene increased M2 macrophages via inhibiting NOTCH1-PI3K-mTOR-NF-κB-JMJD3-IRF4 pathway in response to E. coli infection in macrophages. These results contribute to revealing the pathogenesis of E. coli-caused bovine mastitis, providing the new angle of the prevention and management of mastitis.

An Immune-Regulating Polysaccharide Hybrid Hydrogel with Mild Photothermal Effect and Anti-Inflammatory for Accelerating Infected Wound Healing.

Bacterial infections and excessive inflammation present substantial challenges for clinical wound healing. Hydrogels with mild photothermal (PTT) effects have emerged as promising agents owing to their dual actions: positive effects on cells and negative effects on bacteria. Here, an injectable self-healing hydrogel of oxidized konjac glucomannan/arginine-modified chitosan (OKGM/CS-Arg, OC) integrated with protocatechualdehyde-@Fe (PF) nanoparticles capable of effectively absorbing near-infrared radiation is synthesized successfully. The OC/PF hydrogels exhibit excellent mechanical properties, biocompatibility, and antioxidant activity. Moreover, in synergy with PTT, OC/PF demonstrates potent antibacterial effects while concurrently stimulating cell migration and new blood vessel formation. In methicillin-resistant Staphylococcus aureus-infected full-thickness mouse wounds, the OC/PF hydrogel displays remarkable antibacterial and anti-inflammatory activities, and accelerates wound healing by regulating the wound immune microenvironment and promoting M2 macrophage polarization. Consequently, the OC/PF hydrogel represents a novel therapeutic approach for treating multidrug-resistant bacterial infections and offers a technologically advanced solution for managing infectious wounds in clinical settings.

Teicoplanin-Decorated Reduced Graphene Oxide Incorporated Silk Protein Hybrid Hydrogel for Accelerating Infectious Diabetic Wound Healing and Preventing Diabetic Foot Osteomyelitis.

Developing hybrid hydrogel dressings with anti-inflammatory, antioxidant, angiogenetic, and antibiofilm activities with higher bone tissue penetrability to accelerate diabetic wound healing and prevent diabetic foot osteomyelitis (DFO) is highly desirable in managing diabetic wounds. Herein, the glycopeptide teicoplanin is used for the first time as a green reductant to chemically reduce graphene oxide (GO). The resulting teicoplanin-decorated reduced graphene oxide (rGO) is incorporated into a mixture of silk proteins (SP) and crosslinked with genipin to yield a physicochemically crosslinked rGO-SP hybrid hydrogel. This hybrid hydrogel exhibits high porosity, self-healing, shear-induced thinning, increased cell proliferation and migration, and mechanical properties suitable for tissue engineering. Moreover, the hybrid hydrogel eradicates bacterial biofilms with a high penetrability index in agar and hydroxyapatite disks covered with biofilms, mimicking bone tissue. In vivo, the hybrid hydrogel accelerates the healing of noninfected wounds in a diabetic rat and infected wounds in a diabetic mouse by upregulating anti-inflammatory cytokines and downregulating matrix metalloproteinase-9, promoting M2 macrophage polarization and angiogenesis. The implantation of hybrid hydrogel into the infected site of mouse tibia improves bone regeneration. Hence, the rGO-SP hybrid hydrogel can be a promising wound dressing for treating infectious diabetic wounds, providing a further advantage in preventing DFO.

Short-term, nonsurgical periodontal therapy boosts interleukin-12 levels and reduces oral cancer risk.

Cytokines, including interleukin-12 (IL-12), are proteins that regulate cell survival, proliferation, differentiation, and function. IL-12 is a heterodimeric proinflammatory cytokine. It possesses tumoricidal properties and promotes M1 macrophage polarization and IFN-γ production by T helper (Th1) cells, which in turn stimulates the antitumor cytotoxic cluster of eight positive (CD8+) and natural killer cells, therefore activating an effector immune response against tumor cells. Herein, the IL-2 levels of 60 patients with generalized chronic periodontitis (GCP) were assessed. Plaque index, gingival index, pocket probing depth, bleeding on probing percentage (BOP %), and clinical attachment loss were the clinical indicators reported. Patients with GCP in the pretreatment group had substantially lower mean IL-12 levels than those in the post-treatment group. Short-term, nonsurgical treatment (NST) considerably improved periodontal indices and increased IL-12 levels, thereby reducing oral cancer risk. NST is a cost-effective and accessible cancer prevention procedure for general dentists.

Rv2231c, a unique histidinol phosphate aminotransferase from Mycobacterium tuberculosis, supports virulence by inhibiting host-directed defense

Nitrogen metabolism of M. tuberculosis is critical for its survival in infected host cells. M. tuberculosis has evolved sophisticated strategies to switch between de novo synthesis and uptake of various amino acids from host cells for metabolic demands. Pyridoxal phosphate-dependent histidinol phosphate aminotransferase-HspAT enzyme is critically required for histidine biosynthesis. HspAT is involved in metabolic synthesis of histidine, phenylalanine, tyrosine, tryptophan, and novobiocin. We showed that M. tuberculosis Rv2231c is a conserved enzyme with HspAT activity. Rv2231c is a monomeric globular protein that contains α-helices and β-sheets. It is a secretory and cell wall-localized protein that regulates critical pathogenic attributes. Rv2231c enhances the survival and virulence of recombinant M. smegmatis in infected RAW264.7 macrophage cells. Rv2231c is recognized by the TLR4 innate immune receptor and modulates the host immune response by suppressing the secretion of the antibacterial pro-inflammatory cytokines TNF, IL-12, and IL-6. It also inhibits the expression of co-stimulatory molecules CD80 and CD86 along with antigen presenting molecule MHC-I on macrophage and suppresses reactive nitrogen species formation, thereby promoting M2 macrophage polarization. Recombinant M. smegmatis expressing Rv2231c inhibited apoptosis in macrophages, promoting efficient bacterial survival and proliferation, thereby increasing virulence. Our results indicate that Rv2231c is a moonlighting protein that regulates multiple functions of M. tuberculosis pathophysiology to increase its virulence. These mechanistic insights can be used to better understand the pathogenesis of M. tuberculosis and to design strategies for tuberculosis mitigation.

Exosomal NAT10 from esophageal squamous cell carcinoma cells modulates macrophage lipid metabolism and polarization through ac4C modification of FASN

N-acetyltransferase 10 (NAT10) is acknowledged as a tumor promoter in various cancers due to its role as a regulator of acetylation modification. Tumor-associated macrophages (TAMs) play a pivotal role in the tumor microenvironment (TME). However, the intercellular communication between esophageal squamous cell carcinoma (ESCC) cells and TAMs involving NAT10 remains poorly understood. This study aimed to elucidate the regulatory mechanism of NAT10 in modulating macrophage lipid metabolism and polarization. Experimental evidence was derived from in vitro and in vivo analyses. We explored the association between upregulated NAT10 in ESCC tissues, macrophage polarization, and the therapeutic efficacy of PD-1. Furthermore, we investigated the impact of methyltransferase 3 (METTL3)-induced m6A modification on the increased expression of NAT10 in ESCC cells. Additionally, we examined the role of exosomal NAT10 in stabilizing the expression of fatty acid synthase (FASN) and promoting macrophage M2 polarization through mediating the ac4C modification of FASN. Results indicated that NAT10, packaged by exosomes derived from ESCC cells, promotes macrophage M2 polarization by facilitating lipid metabolism. In vivo animal studies demonstrated that targeting NAT10 could enhance the therapeutic effect of PD-1 on ESCC by mediating macrophage reprogramming. Our findings offer novel insights into improving ESCC treatment through NAT10 targeting.

PGRN is involved in macrophage M2 polarization regulation through TNFR2 in periodontitis

Background and objectiveProgranulin (PGRN), a multifunctional growth factor, plays indispensable roles in the regulation of cancer, inflammation, metabolic diseases, and neurodegenerative diseases. Nevertheless, its immune regulatory role in periodontitis is insufficiently understood. This study attempts to explore the regulatory effects of PGRN on macrophage polarization in periodontitis microenvironment.MethodsImmunohistochemical (IHC) and multiplex immunohistochemical (mIHC) stainings were performed to evaluate the expression of macrophage-related markers and PGRN in gingival samples from periodontally healthy subjects and periodontitis subjects. RAW264.7 cells and bone marrow-derived macrophages (BMDMs) were polarized towards M1 or M2 macrophages by the addition of LPS or IL-4, respectively, and were treated with or without PGRN. Real-time fluorescence quantitative PCR (qRT-PCR), immunofluorescence staining (IF), enzyme-linked immunosorbent assay (ELISA), and flow cytometry were used to determine the expressions of M1 and M2 macrophage-related markers. Co-immunoprecipitation was performed to detect the interaction between PGRN and tumor necrosis factor receptor 2 (TNFR2). Neutralizing antibody was used to block TNFR2 to confirm the role of TNFR2 in PGRN-mediated macrophage polarization.ResultsThe IHC and mIHC staining of human gingival slices showed a significant accumulation of macrophages in the microenvironment of periodontitis, with increased expressions of both M1 and M2 macrophage markers. Meanwhile, PGRN was widely expressed in the gingival tissue of periodontitis and co-expressed mainly with M2 macrophages. In vitro experiments showed that in RAW264.7 cells and BMDMs, M1 markers (CD86, TNF-α, iNOS, and IL-6) substantially decreased and M2 markers (CD206, IL-10, and Arg-1) significantly increased when PGRN was applied to LPS-stimulated macrophages relatively to LPS stimulation alone. Besides, PGRN synergistically promoted IL-4-induced M2 markers expression, such as CD206, IL-10, and Arg1. In addition, the co-immunoprecipitation result showed the direct interaction of PGRN with TNFR2. mIHC staining further revealed the co-localization of PGRN and TNFR2 on M2 macrophages (CD206+). Blocking TNFR2 inhibited the regulation role of PGRN on macrophage M2 polarization.ConclusionsIn summary, PGRN promotes macrophage M2 polarization through binding to TNFR2 in both pro- and anti-inflammatory periodontal microenvironments.

Self-reinforced MOF-based Nanogel Alleviates Osteoarthritis by Long-acting Drug Release.

Intra-articular injection of drugs is an effective strategy for osteoarthritis (OA) treatment. However, the complex microenvironment and limited joint space result in rapid clearance of drugs. Herein, a nanogel-based strategy was proposed for prolonged drug delivery and microenvironment remodeling. Nanogel was constructed through functionalization of hyaluronic acid (HA) by amide reaction on the surface of Kartogenin (KGN)-loaded zeolitic imidazolate framework-8 (denoted as KZIF@HA). Leveraging the inherent hydrophilicity of HA, KZIF@HA spontaneously forms nanogels, ensuring extended drug release in the OA microenvironment. KZIF@HA exhibits sustained drug release over one month, with low leakage risk from the joint cavity compared to KZIF, enhanced cartilage penetration, and reparative effects on chondrocytes. Notably, KGN released from KZIF@HA serves to promote extracellular matrix (ECM) secretion for hyaline cartilage regeneration. Zn2+ release reverses OA progression by promoting M2 macrophage polarization to establish an anti-inflammatory microenvironment. Ultimately, KZIF@HA facilitates cartilage regeneration and OA alleviation within three months. Transcriptome sequencing validates that KZIF@HA stimulates the polarization of M2 macrophages and secretes IL-10 to inhibit the JNK and ERK pathways, promoting chondrocytes recovery and enhancing ECM remodeling. This pioneering nanogel system offers new therapeutic opportunities for sustained drug release, presenting a significant stride in OA treatment strategies. This article is protected by copyright. All rights reserved.

Electrospun Poly-l-Lactic Acid Membranes Promote M2 Macrophage Polarization by Regulating the PCK2/AMPK/mTOR Signaling Pathway.

Electrospun membranes are widely used in tissue engineering. Regretfully, there is limited research on how its morphological characteristics precisely regulate macrophage activation and immune response. Therefore, electrospun poly-l-lactic acid (PLLA) membranes with different alignments (align and random) and diameters (nanoscale and microscale) are prepared to investigate the effects of different surface morphologies on M2 macrophage polarization. Additionally, transcriptome, proteome, and phosphoproteome sequencings are combined to examine the underlying regulatory mechanisms. The results show that the electrospun PLLA membranes with different surface morphologies have good biocompatibility and can regulate the phenotype and function of macrophages by changing the micromorphology of the matrix surface. Especially, macrophages cultured on the electrospun membranes of the A600 group exhibit higher M2 macrophage polarization than the other three groups. Furthermore, the findings demonstrate that electrospun PLLA membranes enhance AMP-activated protein kinase (AMPK)/ mammalian target of rapamycin (mTOR) signaling activation by upregulating the expression of integrin phosphoenolpyruvate carboxykinase 2 (PCK2), which is critical for M2 macrophage polarization. Taken together, electrospun PLLA membranes promote M2 macrophage polarization by regulating the PCK2/AMPK/mTOR signaling pathway. This research can provide further theoretical bases for scaffold design, immunoregulatory mechanisms, and clinical application based on electrospinning technology in the future.

Tumour-derived exosome SNHG17 induced by oestrogen contributes to ovarian cancer progression via the CCL13-CCR2-M2 macrophage axis.

Oestrogen is known to be strongly associated with ovarian cancer. There was much work to show the importance of lncRNA SNHG17 in ovarian cancer. However, no study has revealed the molecular regulatory mechanism and functional effects between oestrogen and SNHG17 in the development and metastasis of ovarian cancer. In this study, we found that SNHG17 expression was significantly increased in ovarian cancer and positively correlated with oestrogen treatment. Oestrogen could promote M2 macrophage polarization as well as ovarian cancer cells SKOV3 and ES2 cell exosomal SNHG17 expression. When exposure to oestrogen, exosomal SNHG17 promoted ovarian cancer cell proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) invitro, and tumour growth and lung metastasis invivo by accelerating M2-like phenotype of macrophages. Mechanically, exosomal SNHG17 could facilitate the release of CCL13 from M2 macrophage via the PI3K-Akt signalling pathway. Moreover, CCL13-CCR2 axis was identified to be involved in ovarian cancer tumour behaviours driven by oestrogen. There results demonstrate a novel mechanism that exosomal SNHG17 exerts an oncogenic effect on ovarian cancer via the CCL13-CCR2-M2 macrophage axis upon oestrogen treatment, of which SNHG17 may be a potential biomarker and therapeutic target for ovarian cancer responded to oestrogen.

IL-4 attenuates myocardial infarction injury by promoting M2 macrophage polarization

IL-4, an immunoregulatory cytokine, plays a role in various cellular pathways and is known to regulate M2 macrophage polarization. Numerous studies have suggested that promoting the polarization of macrophages toward the M2 phenotype is beneficial for myocardial infarction (MI) recovery. However, whether IL-4 can achieve therapeutic effects in MI by regulating M2 macrophage polarization remains unclear. In this study, we observed that IL-4 increased the proportion of M2 macrophages in the ischemic myocardium compared to the PBS group. Additionally, IL-4 reduced the infiltration of inflammatory cells and the expression of proinflammatory-related proteins, while enhancing the expression of genes associated with tissue repair. Furthermore, IL-4 facilitated the recovery of cardiac function and reduced fibrosis in the post-MI phase. Importantly, when macrophages were depleted, the therapeutic benefits of IL-4 mentioned above were attenuated. These findings provide evidence for the effectiveness of IL-4 in treating MI through the regulation of M2 macrophage polarization, thereby encouraging further development of this therapeutic approach.

Short-chain fatty acid-producing bacterial strains attenuate experimental ulcerative colitis by promoting M2 macrophage polarization via JAK/STAT3/FOXO3 axis inactivation

BackgroundPatients with inflammatory bowel disease (IBD), dysbiosis, and immunosuppression who receive fecal microbiota transplantation (FMT) from healthy donors are at an increased risk of developing bacteremia. This study investigates the efficacy of a mixture of seven short-chain fatty acid (SCFA)-producing bacterial strains (7-mix), the resulting culture supernatant mixture (mix-sup), and FMT for treating experimental ulcerative colitis (UC) and evaluates underlying mechanisms.MethodsUtilizing culturomics, we isolated and cultured SCFA-producing bacteria from the stool of healthy donors. We used a mouse model of acute UC induced by dextran sulfate sodium (DSS) to assess the effects of 7-mix, mix-sup, and FMT on intestinal inflammation and barrier function, microbial abundance and diversity, and gut macrophage polarization by flow cytometry, immunohistochemistry, 16S rRNA gene sequencing, and transwell assays.ResultsThe abundance of several SCFA-producing bacterial taxa decreased in patients with UC. Seven-mix and mix-sup suppressed the inflammatory response and enhanced intestinal mucosal barrier function in the mouse model of UC to an extent similar to or superior to that of FMT. Moreover, 7-mix and mix-sup increased the abundance of SCFA-producing bacteria and SCFA concentrations in colitic mice. The effects of these interventions on the inflammatory response and gut barrier function were mediated by JAK/STAT3/FOXO3 axis inactivation in macrophages by inducing M2 macrophage polarization in vivo and in vitro.ConclusionsOur approach provides new opportunities to rationally harness live gut probiotic strains and metabolites to reduce intestinal inflammation, restore gut microbial composition, and expedite the development of safe and effective treatments for IBD.

Essential oil from Cinnamomum cassia Presl bark regulates macrophage polarization and ameliorates lipopolysaccharide-induced acute lung injury through TLR4/MyD88/NF-κB pathway

Cinnamomum cassia Presl, a traditional Chinese medicine recorded in "Shennong's Herbal Classic," has been historically used to treat respiratory diseases and is employed to address inflammation. The essential oil derived from Cinnamomum cassia bark is a primary anti-inflammatory agent. However, there remains ambiguity regarding the chemical composition of cinnamon bark essential oil (BCEO), its principal anti-inflammatory components, and their potential efficacy in typical inflammatory respiratory conditions, such as acute lung injury (ALI). This study aimed to unveil the chemical composition of BCEO. In addition, the mechanism of action of BCEO in ameliorating ALI and regulating macrophage polarization through the TLR4/MyD88/NF-κB pathway was elucidated. BCEO was extracted using supercritical fluid extraction (SFE) and characterized through gas chromatography-mass spectrometry (GC-MS) analysis. Acute oral toxicity was observed in C57BL/6 J mice. The pharmacological effects and underlying mechanisms of BCEO were evaluated in a mouse model of ALI, which was induced by administering 5 mg/kg of lipopolysaccharide (LPS) through intratracheal instillation. GC-MS analysis revealed 99.08% of the constituents of BCEO. The primary components of BCEO were trans-cinnamaldehyde, o-methoxycinnamaldehyde, (+)-α-muurolene, δ-cadinene, and copaene. Oral acute toxicity tests indicated that the maximum tolerated dose of BCEO was 12 g/kg/day. BCEO treatment significantly reduced lung W/D ratio, total protein concentration in BALF, levels of TNF-α, IL-6, and IL-1β in BALF, WBC count and NEU% in peripheral blood, and lung histological damage. Pulmonary function, IL-10 levels, and LYM% in peripheral blood also showed improvement. BCEO effectively decreased the proportion of M1 phenotype macrophages in BALF, M1/M2 ratio, and apoptotic cells in the lung tissue while increasing the proportion of M2 phenotype macrophages in BALF. Furthermore, BCEO treatment led to reduced protein and mRNA levels of TLR4, MyD88, and p-p65, alongside increased p65 expression, suggesting its potential to impede the TLR4/MyD88/NF-κB signaling pathway. SFE-extracted BCEO or its major constituents could serve as a viable treatment for ALI by reducing lung inflammation, improving pulmonary function, and protecting against LPS-induced ALI in mice. This therapeutic effect is achieved by inhibiting M1 macrophage polarization, promoting M2 macrophage polarization, and suppressing the TLR4/MyD88/NF-κB signaling pathway.

COL5A1 promotes triple-negative breast cancer progression by activating tumor cell-macrophage crosstalk.

Triple-negative breast cancer (TNBC) is an exceptionally aggressive subtype of breast cancer. Despite the recognized interplay between tumors and tumor-associated macrophages in fostering drug resistance and disease progression, the precise mechanisms leading these interactions remain elusive. Our study revealed that the upregulation of collagen type V alpha 1 (COL5A1) in TNBC tissues, particularly in chemoresistant samples, was closely linked to an unfavorable prognosis. Functional assays unequivocally demonstrated that COL5A1 played a pivotal role in fueling cancer growth, metastasis, and resistance to doxorubicin, both in vitro and in vivo. Furthermore, we found that the cytokine IL-6, produced by COL5A1-overexpressing TNBC cells actively promoted M2 macrophage polarization. In turn, TGFβ from M2 macrophages drived TNBC doxorubicin resistance through the TGFβ/Smad3/COL5A1 signaling pathway, establishing a feedback loop between TNBC cells and macrophages. Mechanistically, COL5A1 interacted with TGM2, inhibiting its K48-linked ubiquitination-mediated degradation, thereby enhancing chemoresistance and increasing IL-6 secretion. In summary, our findings underscored the significant contribution of COL5A1 upregulation to TNBC progression and chemoresistance, highlighting its potential as a diagnostic and therapeutic biomarker for TNBC.

VDR promotes pancreatic cancer progression in vivo by activating CCL20-mediated M2 polarization of tumor associated macrophage.

Activation of VDR pathway was a promising anti-tumor therapy strategy. However, numerous clinical studies have demonstrated the effect of activating VDR is limited, which indicates that VDR plays a complex role in vivos. We analyzed the TCGA database to examine the association between VDR expression and immune cell infiltration in pancreatic adenocarcinoma (PAAD). Western blot, ELISA, ChIP, and dual-luciferase reporter assays were performed to determine the mechanism of VDR regulating CCL20. Migration assay and immunofluorescence were used to investigate the role of CCL20 in M2 macrophage polarization and recruitment. We employed multiplexed immunohistochemical staining and mouse models to validate the correlation of VDR on macrophages infiltration in PAAD. Flow cytometry analysis of M2/M1 ratio in subcutaneous graft tumors. VDR is extensively expressed in PAAD, and patients with elevated VDR levels exhibited a significantly reduced overall survival. VDR expression in PAAD tissues was associated with increased M2 macrophages infiltration. PAAD cells overexpressing VDR promote macrophages polarization towards M2 phenotype and recruitment in vitro and vivo. Mechanistically, VDR binds to the CCL20 promoter and up-regulates its transcription. The effects of polarization and recruitment on macrophages can be rescued by blocking CCL20. Finally, the relationship between VDR and M2 macrophages infiltration was evaluated using clinical cohort and subcutaneous graft tumors. A positive correlation was demonstrated between VDR/CCL20/CD163 in PAAD tissues and mouse models. High expression of VDR in PAAD promotes M2 macrophage polarization and recruitment through the secretion of CCL20, which activates tumor progression. This finding suggests that the combination of anti-macrophage therapy may improve the efficacy of VDR activation therapy in PAAD.

Mesenchymal stem cells induce an immunosuppressive microenvironment in pituitary tumors.

The tumor microenvironment (TME) includes diverse cellular components such as mesenchymal stem cells (MSC) and immune cells among others. MSC have been isolated from different tumors and they favor tumor cell growth, however, their role in pituitary tumors (PT) remains unknown. Herein we report the presence of MSCs in 2 ACTH-secreting PT causing Cushing disease (MCU), 2 nonfunctioning adenomas of gonadotrope differentiation (MNF) and 2 non tumoral pituitary glands (MS). We have analyzed their transcriptomic profiles by RNAseq and compared MSC in terms of their immunosuppressive effects against lymphoid T cell and macrophage populations by means of co-cultures and flow cytometry. Our transcriptomic analysis revealed molecular differences between MSC derived from non-tumoral pituitaries and MSC derived from PT. Two distinct subpopulations of MSC, one displaying immunosuppressive properties and the other with increased pro-proliferative capabilities, regardless of their origin. MSC derived from ACTH- and nonfunctioning PT, but not those derived from non-tumoral glands significantly inhibited the proliferation of activated T cells, favored the generation of Tregs and promote M2 macrophage polarization. Such immunosuppressive effects were correlated with an upregulation of programmed death ligand 1 and intracellular expression of macrophage colony stimulating factor (M-CSF) and IL-10. Importantly, MSC derived from ACTH-PT showed a higher immunosuppressive potential than MSC isolated from nonfunctioning tumors. This study demonstrates the presence of at least two MSC subpopulations in the pituitary gland and suggests that immunosuppressive effects of MSC may have important implications in PT growth.

The GFPT2-O-GlcNAcylation-YBX1 axis promotes IL-18 secretion to regulate the tumor immune microenvironment in pancreatic cancer

The immunosuppressive microenvironment caused by several intrinsic and extrinsic mechanism has brought great challenges to the immunotherapy of pancreatic cancer. We identified GFPT2, the key enzyme in hexosamine biosynthesis pathway (HBP), as an immune-related prognostic gene in pancreatic cancer using transcriptome sequencing and further confirmed that GFPT2 promoted macrophage M2 polarization and malignant phenotype of pancreatic cancer. HBP is a glucose metabolism pathway leading to the generation of uridine diphosphate N-acetylglucosamine (UDP-GlcNAc), which is further utilized for protein O-GlcNAcylation. We confirmed GFPT2-mediated O-GlcNAcylation played an important role in regulating immune microenvironment. Through cellular proteomics, we identified IL-18 as a key downstream of GFPT2 in regulating the immune microenvironment. Through CO-IP and protein mass spectrum, we confirmed that YBX1 was O-GlcNAcylated and nuclear translocated by GFPT2-mediated O-GlcNAcylation. Then, YBX1 functioned as a transcription factor to promote IL-18 transcription. Our study elucidated the relationship between the metabolic pathway of HBP in cancer cells and the immune microenvironment, which might provide some insights into the combination therapy of HBP vulnerability and immunotherapy in pancreatic cancer.

Disulfiram Improves Fat Graft Retention by Modulating Macrophage Polarization Via Inhibition of NLRP3 Inflammasome-Mediated Pyroptosis.

Macrophage-mediated inflammatory response in the early post-grafting period restricts fat graft retention. Pyroptosis is a novel type of programmed cell death that extensively participates in inflammatory pathologies. This study sought to determine whether macrophage pyroptosis is activated during the inflammatory phase after fat grafting and to investigate the efficacy of a pyroptosis inhibitor, disulfiram (DSF) in fat graft retention. We established a C57BL/6 mice fat grafting model and then analyzed macrophage pyroptosis. DSF (50 mg/kg, every other day) was intraperitoneally injected started from 1 h prior to fat grafting and continued for 14 days. An in vitro co-culture system was established in which mouse RAW264.7 macrophages were co-cultured with apoptotic adipocytes to further validate the findings of the in vivo studies and to explore the underlying mechanisms. Here we reported that macrophage pyroptosis was activated in both fat grafts and in vitro co-culture models. DSF was found to be a potent pyroptosis inhibitor to promote M2 macrophage polarization. In addition, DSF was demonstrated to enhance vascularization and graft retention. Our results suggested that pyroptosis plays a crucial role in the inflammatory cascade within fat grafts. DSF, being a clinically available drug could be translated into a clinically effective drug for improving fat graft survival via inhibiting macrophage pyroptosis, thereby inducing M2 macrophage polarization and promoting neovascularization.

Self-responsive H2-releasing microneedle patch temporally adapts to the sequential microenvironment requirements for optimal diabetic wound healing

Oxidative stress regulation and synchronized promotion of angiogenesis are critical factors in the healing process of diabetic wounds. However, existing research often fails to fully consider the dynamic interplay between these two biological processes and their time-dependent roles in diabetic wound healing. This study innovatively introduces a novel hydrogen (H2)-releasing microneedle patch capable of precisely controlling the regulation of oxidative stress and the promotion of angiogenesis through a bidirectional responsive mechanism of microneedles and backing layers. Specifically, we employ ammonia borane (AB)-loaded mesoporous silica nanoparticles (MSN) as a source of H2, combined with polyvinyl pyrrolidone (PVP) to fabricate microneedles. This design effectively clears excessive reactive oxygen species (ROS) in deep tissues and promotes the M2 polarization of macrophages. Concurrently, we utilize cobalt-adsorbed graphene oxide (GO/Co2+) mixed with polyvinyl alcohol (PVA) to prepare backing layers, which not only release Co2+ upon the reduction of oxygen-containing functional groups in GO by H2 diffused from deep tissues to synergize with H2 for enhanced vascularization, but also endow the microneedle patch with near-infrared light-responsive antimicrobial properties, crucial for managing diabetic infected wounds. Through this innovative dual-action mechanism, our research significantly accelerates the healing process of infected wounds in a diabetic mouse model. Moreover, single-cell sequencing results further confirm the pivotal role of H2 in regulating oxidative stress, promoting macrophage M2 polarization, and stimulating angiogenesis. These results not only showcase the unique features of our microneedle patch but also offer new perspectives and therapeutic strategies for the treatment of diabetic wounds.

SFRP1 decreases WNT-Mediated M2 macrophage marker expression in breast tissue

The Wnt family of secreted proteins are involved in mammary gland development and tumorigenesis. It has recently been shown that Wnt ligands promote M2 macrophage polarization and so we sought to determine the effects of a Wnt signaling antagonist, Secreted Frizzled Related Protein 1 (SFRP1), on M2 marker expression. We measured a murine M2 marker (Arg1) in mice with a targeted deletion of Sfrp1 during different stages of mammary gland development including puberty, pregnancy, and lactation, as well as in response to obesity. Next, to determine whether Wnt signaling/antagonism affects human M2 markers (CD209 and CCL18), we treated a human patient derived explant (PDE) breast tissue sample with exogenous Wnt3a in the presence and absence of rSFRP1. Finally, we expanded our PDE study to 13 patients and performed bulk RNAseq analysis following the treatment described above. We found that in loss of Sfrp1 in the murine mammary gland increased Arg1 expression. Moreover, we showed that Wnt3a increases CD209 and CCL18 mRNA and protein expression in breast PDEs and that their expression is decreased in response to rSFRP1. Our RNAseq analysis unveiled novel genes that were affected by Wnt3a treatment and subsequently reversed when rSFRP1 was added. Validation of these data exhibited that chemokines involved in promoting macrophage polarization and cancer metastasis, including CCL11 and CCL26, were stimulated by Wnt3a signaling and their expression was abrogated by treatment with rSFRP1. Our data suggest that SFRP1 may be an important mediator that tempers Wnt signaling in the tumor microenvironment.