Th17/Treg balance and macrophage polarization ratio in lower extremity arteriosclerosis obliterans

Objective:To explore the balance of peripheral blood T helper 17 cells/regulatory T cell(Th17/Treg)ratio and the polarization ratio of M1 and M2 macrophages in lower extremity arteriosclerosis obliterans(ASO).Methods:A rat model of lower extremity ASO was established,and blood samples from patients with lower extremity ASO before and after surgery were obtained.ELISA was used to detect interleukin 6(IL-6),IL-10,and IL-17.Real-time RCR and Western blot analyses were used to detect Foxp3,IL-6,IL-10,and IL-17 expression.Moreover,flow cytometry was applied to detect the Th17/Treg ratio and M1/M2 ratio.Results:Compared with the control group,the iliac artery wall of ASO rats showed significant hyperplasia,and the concentrations of cholesterol and triglyceride were significantly increased(P<0.01),indicating the successful establishment of ASO.Moreover,the levels of IL-6 and IL-17 in ASO rats were pronouncedly increased(P<0.05),while the IL-10 level was significantly decreased(P<0.05).In addition to increased IL-6 and IL-17 levels,the mRNA and protein levels of Foxp3 and IL-10 in ASO rats were significantly decreased compared with the control group.The Th17/Treg and M1/M2 ratios in the ASO group were markedly increased(P<0.05).These alternations were also observed in ASO patients.After endovascular surgery(such as percutaneous transluminal angioplasty and arterial stenting),all these changes were significantly improved(P<0.05).Conclusions:The Th17/Treg and M1/M2 ratios were significantly increased in ASO,and surgery can effectively improve the balance of Th17/Treg,and reduce the ratio of M1/M2,and the expression of inflammatory factors.

ScRNA-seq reveals the correlation between M2 phenotype of tumorassociated macrophages and lymph node metastasis of breast cancer

The process of lymphatic metastasis was proved to be associated with podoplanin-expressing macrophages in breast cancer(BC).This study aimed to investigate the role of the M2 phenotype of tumor-associated macrophages and mine the key M2 macrophages-related genes for lymph node metastasis in BC.We downloaded the GSE158399 dataset from the Gene Expression Omnibus(GEO)database,which includes transcriptomic profiles of individual cells from primary tumors,negative lymph nodes(NLNs),and positive lymph nodes(PLNs)of breast cancer patients.The cell subsets were identified by clustering analysis after quality control of the scRNA-seq using Seurat.The activation and migration capability of M2 macrophages were evaluated with R package“GSVA”.The key M2 macrophages-related genes were screened from the differential expressed genes(DEGs)and M2 macrophages activation and migration gene sets collected from MSigDB database.Our analysis identified three main cell types in primary tumors,NLNs,and PLNs:basal cells,luminal cells,and immune cell subsets.The further cell type classification of immune cell subsets indicated M2 macrophages accumulation in NLs and PLs.The GSVA enrichment scores for activation and migration capability were increased significantly in M2 macrophages from primary tumors than NLNs and PLNs(pvalue<0.001).Seven M2 macrophages activation-related and 15 M2 macrophages migration-related genes were significantly up-regulated in primary tumors than NLNs and PLNs.The proportion and GSVA enrichment scores for activation and migration of M2 macrophages may be potential markers for lymph node metastasis in breast cancer.Our study demonstrated that twenty-two up-regulated mRNA may be possible therapeutic targets for lymph node metastasis in breast cancer.

Growth differentiation factor 11 promotes macrophage polarization towards M2 to attenuate myocardial infarction via inhibiting Notch1 signaling pathway

Background:Myocardial infarctions(MI)is a major threat to human health especially in people exposed to cold environment.The polarization of macrophages towards different functional phenotypes(M1 macrophages and M2 macrophages)is closely related to MI repairment.The growth differentiation factor 11(GDF11)has been reported to play a momentous role in inflammatory associated diseases.In this study,we examined the regulatory role of GDF11 in macrophage polarization and elucidated the underlying mechanisms in MI.Methods:In vivo,the mice model of MI was induced by permanent ligation of the left anterior descending coronary artery(LAD),and mice were randomly divided into the sham group,MI group,and MI+GDF11 group.The protective effect of GDF11 on myocardial infarction and its effect on macrophage polarization were verified by echocardiography,triphenyl tetrazolium chloride staining and immunofluorescence staining of heart tissue.In vitro,based on the RAW264.7 cell line,the effect of GDF11 in promoting macrophage polarization toward the M2 type by inhibiting the Notch1 Signaling pathway was validated by qRT-PCR,Western blot,and flow cytometry.Results:We found that GDF11 was significantly downregulated in the cardiac tissue of MI mice.And GDF11 supplementation can improve the cardiac function.Moreover,GDF11 could reduce the proportion of M1 macrophages and increase the accumulation of M2 macrophages in the heart tissue of MI mice.Furthermore,the cardioprotective effect of GDF11 on MI mice was weakened after macrophage clearance.At the cellular level,application of GDF11 could inhibit the expression of M1 macrophage(classically activated macrophage)markers iNOS,interleukin(IL)-1β,and IL-6 in a dose-dependent manner.In contrast,GDF11 significantly increased the level of M2 macrophage markers including IL-10,CD206,arginase 1(Arg1),and vascular endothelial growth factor(VEGF).Interestingly,GDF11 could promote M1 macrophages polarizing to M2 macrophages.At the molecular level,GDF11 significantly down-regulated the Notch1 signaling pathway,the activation of which has been demonstrated to promote M1 polarization in macrophages.Conclusions:GDF11 promoted macrophage polarization towards M2 to attenuate myocardial infarction via inhibiting Notch1 signaling pathway.

Exosomal microRNA-588 from M2 polarized macrophages contributes to cisplatin resistance of gastric cancer cells

BACKGROUND Gastric cancer is a prevalent malignant cancer with a high incidence and significantly affects the health of modern people globally.Cisplatin(DDP)is one of the most common and effective chemotherapies for patients with gastric cancer,but DDP resistance remains a severe clinical challenge.AIM To explore the function of M2 polarized macrophages-derived exosomal microRNA(miR)-588 in the modulation of DDP resistance of gastric cancer cells.METHODS M2 polarized macrophages were isolated and identified by specific markers using flow cytometry analysis.The exosomes from M2 macrophages were identified by transmission electron microscopy and related markers.The uptake of the PKH67-labelled M2 macrophages-derived exosomes was detected in SGC7901 cells.The function and mechanism of exosomal miR-588 from M2 macrophages in the modulation of DDP resistance of gastric cancer cells was analyzed by CCK-8 assay,apoptosis analysis,colony formation assay,Western blot analysis,qPCR analysis,and luciferase reporter assay in SGC7901 and SGC7901/DDP cells,and by tumorigenicity analysis in nude mice.RESULTS M2 polarized macrophages were isolated from mouse bone marrow stimulated with interleukin(IL)-13 and IL-4.Co-cultivation of gastric cancer cells with M2 polarized macrophages promoted DDP resistance.M2 polarized macrophagesderived exosomes could transfer in gastric cancer cells to enhance DDP resistance.Exosomal miR-588 from M2 macrophages contributed to DDP resistance of gastric cancer cells.miR-588 promoted DDP-resistant gastric cancer cell growth in vivo.miR-588 was able to target cylindromatosis(CYLD)in gastric cancer cells.The depletion of CYLD reversed miR-588 inhibition-regulated cell proliferation and apoptosis of gastric cancer cells exposed to DDP.CONCLUSION In conclusion,we uncovered that exosomal miR-588 from M2 macrophages contributes to DDP resistance of gastric cancer cells by partly targeting CYLD.miR-588 may be applied as a potential therapeutic target for the treatment of gastric cancer.

Macrophage-derived exosomal miR-342-3p promotes the progression of renal cell carcinoma through the NEDD4L/CEP55 axis

Due to its difficulty in early diagnosis and lack of sensitivity to chemotherapy and radiotherapy,renal cell carcinoma(RCC)remains to be a frequent cause of cancer-related death.Here,we probed into new targets for its early diagnosis and treatment for RCC.microRNA(miRNA)data of M2-EVs and RCC were searched on the Gene Expression Omnibus database,followed by the prediction of the potential downstream target.Expression of target genes was measured via RT-qPCR and Western blot,respectively.M2 macrophage was obtained viaflow cytometry with M2-EVs extracted.The binding ability of miR-342-3p to NEDD4L and to CEP55 ubiquitination was studied with their roles in the physical abilities of RCC cells assayed.Subcutaneous tumor-bearing mouse models and lung metastasis models were prepared to observe in vivo role of target genes.M2-EVs induced RCC growth and metastasis.miR-342-3p showed high expression in both M2-EVs and RCC cells.M2-EVs carrying miR-342-3p promoted RCC cell abilities to proliferate,invade and migrate.In RCC cells,M2-EV-derived miR-342-3p could specifically bind to NEDD4L and consequently elevate CEP55 protein expression via suppressing NEDD4L,thereby exerting tumor-promoting effects.CEP55 could be degraded by ubiquitination under the function of NEDD4L,and miR-342-3p delivered by M2-EVs facilitated the RCC occurrence and development by activating the PI3K/AKT/mTOR signaling pathway.In conclusion,M2-EVs promote RCC growth and metastasis by delivering miR-342-3p to suppress NEDD4L and subsequently inhibit CEP55 ubiquitination and degradation via activation of the PI3K/AKT/mTOR signaling pathway,strongly driving the proliferative,migratory and invasive of RCC cells.

Effect of Pingchuan granule on typeⅡinnate lymphocytes and M2 polarization of macrophages in asthmatic mice

Objective:To observe the effect of Pingchuan granule on the number of typeⅡinnate lymphocytes(ILC2)and M2 polarization of macrophages in the lung tissue of asthmatic mice;Methods:Ovalbumin sensitized and challenged asthmatic mouse models were established,and then Pingchuan granules or IL-33 neutralizing antibody were given to intervene.The pathological morphology of lung tissue was observed by HE,PAS and Masson staining,and the expressions of IL-4,IL-5,IL-13 and IL-33 in BALF and lung tissue were detected by ELISA and qRT-PCR,Flow cytometry was used to detect the number of type II innate lymphocytes and type M2 macrophages in lung tissue.Western blot was used to detect the protein expression levels of ST-2,FIZZ1 and Arg-1 in lung tissue;Results:Compared with the control group,the inflammation score,PAS score and collagen staining area of the model group were significantly increased,the expressions of IL-4,IL-5,IL-13 and IL-33 in BALF and lung tissue were significantly increased,the number of ILC2 and M2 macrophages,the expression of ST-2,FIZZ1 and Arg-1 protein in lung tissue were significantly increased,and the differences were statistically significant(P<0.05);Compared with the model group,Pingchuan granule could significantly reduce the inflammation score,PAS score and collagen staining area of asthmatic mice,down-regulate the expression of IL-4,IL-5,IL-13 and IL-33 in BALF and lung tissue,reduce the number of ILC2 and M2 macrophages,and the expression of ST-2,FIZZ1 and Arg-1 protein in lung tissue(P<0.05);Conclusion:Pingchuan granule improve the airway remodeling of asthma by inhibiting the polarization of M2 macrophages mediated by ILC2.

Morphofunctional Characteristics of Pulmonary Surfactant System and Its Effect on Immune Cells in Influenza A (H1N1) Pathogenesis

There is an annual increase of influenza-related SARI cases in winter months. Despite the high relevance of this problem, influenza pathogenesis and the role of surfactant system and its SP-A (surfactant protein A) enzyme in antiviral defense remain poorly understood. SP-A activates macrophage M1 polarization and triggers an antiviral response due to the activation of T-cells and dendritic cells. Therefore, surfactant system is an important element of infection protection and a promising therapeutic target.

Dual-functional microneedle with programmatic regulation of macrophage for autoimmune psoriasis treatment

Modulating the immune microenvironment to establish sustained positive feedback within immune pathways represents a promising avenue for the treatment of autoimmunity.However,the precise and efficient delivery of therapeutic systems to the subcutaneous basal layer to modulate immune disorders is a major challenge in the treatment of autoimmune psoriasis.In this project,we introduce a dual-functional microneedle(DF-MN)designed to combine MNs with multiple release kinetics and immunotherapy,the programmed treatment is achieved through segmented design of the MN structure,realizing the unification of rapid and long-lasting treatment of autoimmune psoriasis.In vivo imaging results showed that GelMA@M-CSF showed fluorescent signals after 5 days of delivery to subcutaneous tissues,whereas HA@IL-13 showed minimal fluorescent signals after 2 days.The multistage release behavior of MNs and the diffusion mechanism of drugs were explained at the molecular level,in combination with coarse-grained molecular dynamics.Additionally,DF-MN can successfully induce macrophage reprogramming in vitro and ameliorate overall symptoms in a psoriasis mice model,suggesting that it has the potential to be an effective strategy for the treatment of psoriasis and portends to be a transformative platform for the treatment of other autoimmune diseases.

Thylakoid engineered M2 macrophage for sonodynamic effect promoted cell therapy of early atherosclerosis

Atherosclerosis is the most common cause of cardiovascular diseases that contribute to the major morbidity worldwide,but still lacking of effective treatment strategy.Here,a hybrid cell is constructed for the sonodynamic effect promoted cell therapy of early atherosclerosis by fusing M2 macrophages with thylakoid(TK)membranes.After systemic administration,the obtained TK-M2 actively accumulates in the early atherosclerotic plaques,wherein M2 macrophages relieve the cholesterol accumulation and the inflammation in the foam cells.Meanwhile,the TK membranes decorated on the M2 macrophages exhibit both type I and type II sonodynamic effects under ultrasound(US)activation,inducing the direct apoptosis of foam cells.The cooperation of M2 and TK leads to significant outcome in eliminating atherosclerotic plaques without obvious side-effects,providing a new avenue for atherosclerosis treatment.

Calculus bovis inhibits M2 tumor-associated macrophage polarization via Wnt/β-catenin pathway modulation to suppress liver cancer

BACKGROUND Calculus bovis(CB),used in traditional Chinese medicine,exhibits anti-tumor effects in various cancer models.It also constitutes an integral component of a compound formulation known as Pien Tze Huang,which is indicated for the treatment of liver cancer.However,its impact on the liver cancer tumor microenvironment,particularly on tumor-associated macrophages(TAMs),is not well understood.AIM To elucidate the anti-liver cancer effect of CB by inhibiting M2-TAM polarization via Wnt/β-catenin pathway modulation.METHODS This study identified the active components of CB using UPLC-Q-TOF-MS,evaluated its anti-neoplastic effects in a nude mouse model,and elucidated the underlying mechanisms via network pharmacology,transcriptomics,and molecular docking.In vitro assays were used to investigate the effects of CB-containing serum on HepG2 cells and M2-TAMs,and Wnt pathway modulation was validated by real-time reverse transcriptase-polymerase chain reaction and Western blot analysis.RESULTS This study identified 22 active components in CB,11 of which were detected in the bloodstream.Preclinical investigations have demonstrated the ability of CB to effectively inhibit liver tumor growth.An integrated approach employing network pharmacology,transcriptomics,and molecular docking implicated the Wnt signaling pathway as a target of the antineoplastic activity of CB by suppressing M2-TAM polarization.In vitro and in vivo experiments further confirmed that CB significantly hinders M2-TAM polarization and suppresses Wnt/β-catenin pathway activation.The inhibitory effect of CB on M2-TAMs was reversed when treated with the Wnt agonist SKL2001,confirming its pathway specificity.CONCLUSION This study demonstrated that CB mediates inhibition of M2-TAM polarization through the Wnt/β-catenin pathway,contributing to the suppression of liver cancer growth.

IGF2BP3 Enhances the Growth of Hepatocellular Carcinoma Tumors by Regulating the Properties of Macrophages and CD8^(+)T Cells in the Tumor Microenvironment

Background and Aims:Overexpression of IGF2BP3 is associated with the prognosis of hepatocellular carcinoma(HCC).However,its role in regulating tumor immune microenvironment(TME)is not well characterized.Here,we investigated the effects of IGF2BP3 on macrophages and CD8^(+)T cells within the TME of HCC.Methods:The relationship between IGF2BP3 and immune cell infiltration was analyzed using online bioinformatics tools.Knockout of IGF2BP3 in mouse hepatoma cell line Hepa1-6 was established using CRISPR/Cas9 technology.In vitro cell coculture and subcutaneously implanted hepatoma mice model were used to explore the effects of IGF2BP3 on immune cells.Expression of CCL50l transforming growth factor beta 1(TGF-β1)was detected with quantitative real-time polymerase chain reaction,western blotting,and enzyme-linked immunosorbent assay.The binding of IGF2BP3 and its target RNA was verified by trimolecular fluorescence complementation system and RNA immunoprecipitation followed by quantitative or semiquantitative polymerase chain reaction.Results:IGF2BP3 expression was elevated in HCC and was positively correlated with macrophage infiltration.Patients with higher IGF2BP3 expression and lower macrophage infiltration had a better survival rate.We found that IGF2BP3 could bind to the mRNA of CCL5 or TGF-β1,increasing their expression,and inducing macrophage infiltration and M2 polarization while inhibiting the activation of CD8^(+)T cells.Furthermore,inhibition of IGF2BP3 combined with anti-CD47 antibody treatment significantly suppressed the growth of hepatoma in Hepa1-6 xenograft tu-mor mice.Conclusions:IGF2BP3 promoted the infiltration and M2-polarization of macrophages and suppressed CD8^(+)T activation by enhancing CCL5 and TGF-β1 expression,which facilitated the progression of Hepa1-6 xenograft tumor.

Ultrasound-visualized nanocarriers with siRNA for targeted inhibition of M2-like TAM polarization to enhance photothermal therapy in NSCLC

Photothermal therapy(PTT)has received a lot of attention as a promising strategy for eliminating tumors quickly.However,the unavoidable inflammatory response during the treatment might result in a high concentration of M2-like tumor-associated macrophages(TAMs),increasing the risk of tumor recurrence and metastasis.To address this problem,gold-based nanocarriers(PGMP-small interfering RNA(siRNA)nanoparticles(NPs))containing STAT6siRNA,that inhibited M2-like TAM polarization,were designed and investigated for PTT and gene therapy of non-small cell lung cancer(NSCLC).In an NSCLC model,the nanocarriers demonstrated excellent siRNA delivery ability and a high gene transfection rate of up to 90%in macrophages,thus inhibiting the polarization of about 87%of M2-like TAMs and effectively suppressing the invasion and metastasis of NSCLC.Meanwhile,the unique gold nanosphere structure offered improved PTT and contrast-enhanced ultrasound imaging,thus contributing to the efficient elimination and real-time monitoring of the tumor tissues.These nanocarriers with combined gene and photothermal therapeutic capabilities improved the efficacy of single-modality treatment,and showed the potential to inhibit cancer cell recurrence and metastasis to ultimately cure NSCLC.

Co-administration of platelet-rich plasma and small intestinal submucosa is more beneficial than their individual use in promoting acute skin wound healing

Background:Acute skin wounds may compromise the skin barrier,posing a risk of infection.Small intestinal submucosa(SIS)is widely used to treat acute and chronic wounds.However,the efficacy of SIS to accelerate wound healing still needs to be improved to meet clinical demands.To tackle this problem,platelet-rich plasma(PRP)is used due to its potency to promote proliferation,migration and adhesion of target cells.In this study,we applied PRP and SIS to skin wounds to explore their effects on wound healing by evaluating re-epithelialization,collagen production,angiogenesis and the inflammatory response.Methods:A1×1-cm full-thickness skin defectwas established in mice.Sixty mice were divided into four treatment groups:PRP+SIS,PRP,SIS and control.On days 3,5,7,10 and 14 post-surgery,tissue specimens were harvested.Haematoxylin and eosin,Masson’s trichrome,immunohistochemical and immunofluorescence double staining were used to visualize epidermal thickness,collagen and vascular regeneration and inflammation.Results:Wound contraction in the PRP and PRP+SIS groups was significantly greater,compared with the other groups,on days 3 and 5 post-surgery.A histological analysis showed higher collagen expression in the PRP and PRP+SIS groups on day 7,whichwas associated with a thicker epidermal layer on day 14.In addition,immunohistochemical staining showed that CD31-positive blood vessels and vascular endothelial growth factor expression in the PRP+SIS and PRP groups were significantly higher,compared with the control group.Furthermore,immunofluorescence double staining showed that the number of M1 and M2 macrophages in the PRP+SIS and PRP groups was higher,compared with the control and SIS groups alone,on day 3.However,on day 7,the number of M1 macrophages dramatically decreased in the PRP+SIS and PRP groups.The ratio of M2 to M1 macrophages in the PRP+SIS and PRP groups was 3.97 and 2.93 times that of the control group and 4.56 and 3.37 times that of the SIS group,respectively.Conclusion:Co-administration of SIS and PRP has a better effect on promoting angiogenesis,reepithelialization and collagen regeneration in managing acute wound healing than either agent alone.

Tryptophan 2,3-dioxygenase 2 controls M2 macrophages polarization to promote esophageal squamous cell carcinoma progression via AKT/GSK3β/IL-8 signaling pathway

Tryptophan 2,3-dioxygnease 2(TDO2) is specific for metabolizing tryptophan to kynurenine(KYN),which plays a critical role in mediating immune escape of cancer.Although accumulating evidence demonstrates that TDO2 overexpression is implicated in the development and progression of multiple cancers,its tumor-promoting role in esophageal squamous cell carcinoma(ESCC) remains unclear.Here,we observed that TDO2 was overexpressed in ESCC tis sues and correlated significantly with lymph node metastasis,advanced clinical stage,and unfavorable prognosis.Functional experiments showed that TDO2 promoted tumor cell proliferation,migration,and colony formation,which could be prevented by inhibition of TDO2 and aryl hydrocarb on receptor(AHR).Further experimentation demonstrated that TDO2 could promote the tumor growth of KYSE150 tumor-bearing model,tumor burden of C57 BL/6 mice with ESCC induced by 4-NQO,enhance the expression of phosphorylated AKT,with subsequent pho sphorylation of GSK3β,and polarization of M2 macrophages by upregulating interleukin-8(IL-8) to accelerate tumor progression in the tumor microenvironment(TME).Collectively,our results discovered that TDO2 could upregulate IL-8 through AKT/GSK3β to direct the polarization of M2 macrophages in ESCC,and suggested that TDO2 could represent as an attractive therapeutic target and prognostic marker to ESCC.

A BRD4 PROTAC nanodrug for glioma therapy via the intervention of tumor cells proliferation,apoptosis and M2 macrophages polarization

Glioma is a primary aggressive brain tumor with high recurrence rate.The poor efficiency of chemotherapeutic drugs crossing the blood-brain barrier(BBB) is well-known as one of the main challenges for anti-glioma therapy.Moreover,massive infiltrated tumor-associated macrophages(TAMs) in glioma further thwart the drug efficacy.Herein,a therapeutic nanosystem(SPP-ARV-825) is constructed by incorporating the BRD4-degrading proteolytic targeting chimera(PROTAC) ARV-825 into the complex micelle(SPP) composed of substance P(SP) peptide-modified poly(ethylene glycol)-poly(D,L-lactic acid)(SP-PEG-PDLL A) and methoxy poly(ethylene glycol)-poly(D,L-lac tic acid)(mPEG-PDLL A,PP),which could penetrate BBB and target brain tumor.Subsequently,released drug engenders antitumor effect via attenuating cells proliferation,inducing cells apoptosis and suppressing M2 macrophages polarization through the inhibition of IRF4 promoter transcription and phosphorylation of STAT6,STAT3 and AKT.Taken together,our work demonstrates the versatile role and therapeutic efficacy of SPP-ARV-825 micelle against glioma,which may provide a novel strategy for glioma therapy in future.

Gold nanoparticle-directed autophagy intervention for antitumor immunotherapy via inhibiting tumor-associated macrophage M2 polarization

Tumor-associated macrophages(TAMs),one of the dominating constituents of tumor microenvironment,are important contributors to cancer progression and treatment resistance.Therefore,regulation of TAMs polarization from M2 phenotype towards M1 phenotype has emerged as a new strategy for tumor immunotherapy.Herein,we successfully initiated antitumor immunotherapy by inhibiting TAMs M2 polarization via autophagy intervention with polyethylene glycol-conjugated gold nanoparticles(PEG-Au NPs).PEG-Au NPs suppressed TAMs M2 polarization in both in vitro and in vivo models,elicited antitumor immunotherapy and inhibited subcutaneous tumor growth in mice.As demonstrated by the m RFP-GFP-LC3 assay and analyzing the autophagy-related proteins(LC3,beclin1 and P62),PEGAu NPs induced autophagic flux inhibition in TAMs,which is attributed to the PEG-Au NPs induced lysosome alkalization and membrane permeabilization.Besides,TAMs were prone to polarize towards M2phenotype following autophagy activation,whereas inhibition of autophagic flux could reduce the M2polarization of TAMs.Our results revealed a mechanism underlying PEG-Au NPs induced antitumor immunotherapy,where PEG-Au NPs reduce TAMs M2 polarization via induction of lysosome dysfunction and autophagic flux inhibition.This study elucidated the biological effects of nanomaterials on TAMs polarization and provided insight into harnessing the intrinsic immunomodulation capacity of nanomaterials for effective cancer treatment.

Phosphatidylserine released from apoptotic cells in tumor induces M2-like macrophage polarization through the PSR-STAT3-JMJD3 axis

Background:Understanding how the tumor microenvironment is shaped by various factors is important for the development of new therapeutic strategies.Tumor cells often undergo spontaneous apoptotic cell death in tumor microen-vironment,these apoptotic cells are histologically co-localized with immunosup-pressive macrophages.However,the mechanism by which tumor cell apoptosis modulates macrophage polarization is not fully understood.In this study,we aimed to explore the tumor promoting effects of apoptotic tumor cells and the signal pathways involved.Methods:Apoptotic cells and macrophages in tumors were detected by immunohistochemical staining.Morphological analysis was performed with Giemsa staining.Lipids generated from apoptotic cells were detected by liq-uid chromatography-mass spectrometry.Phosphatidylserine-containing lipo-somes were prepared to mimic apoptotic cells.The expression of protein was determined by real-time PCR,immunohistochemistry enzyme-linked immunosorbent assay and Western blotting.Mouse malignant ascites and subcu-taneous tumor models were designed for in vivo analysis.Transgenic mice with specific genes knocked out and inhibitors specific to certain proteins were used for the mechanistic studies.Results:The location and the number of apoptotic cells were correlated with that of macrophages in several types of carcinomas.Phosphatidylserine,a lipid molecule generated in apoptotic cells,induced polarization and accumulation of M2-like macrophages in vivo and in vitro.Moreover,sustained administration of phosphoserine promoted tumor growth in the malignant ascites and subcuta-neous tumor models.Further analyses suggested that phosphoserine induced a M2-like phenotype in macrophages,which was related to the activation of phosphoserine receptors including T-cell immunoglobin mucin 4(TIM4)and the FAK-SRC-STAT3 signaling pathway as well as elevated the expression of the histone demethylase Jumonji domain-containing protein 3(JMJD3).Adminis-tration of specific inhibitors of these pathways could reduce tumor progression.Conclusions:This study suggest that apoptotic cell-generated phosphoserine might be a notable signal for immunosuppressive macrophages in tumors,and the related pathways might be potential therapeutic targets for cancer therapy.