Recruitment Of M2 Macrophages Research Articles

STC1 competitively binding βPIX enhances melanoma progression via YAP nuclear translocation and M2 macrophage recruitment through the YAP/CCL2/VEGFA/AKT feedback loop

This study investigates the role of Stanniocalcin-1 (STC1) in melanoma progression, with a focus on its impact on metastasis, angiogenesis, and immune evasion. Systematic bioinformatics analysis revealed the potential influence of STC1 dysregulation on prognosis, immune cell infiltration, response to immune therapy, and cellular functions. In vitro assays were conducted to assess the proliferation, invasion, migration, and angiogenesis capabilities of A375 cells. In vivo experiments utilizing C57BL/6 J mice established a lung metastasis model using B16-F10 cells to evaluate macrophage infiltration and M2 polarization. A Transwell co-culture system was employed to explore the crosstalk between melanoma and macrophages. Molecular interactions among STC1, YAP, βPIX, and CCL2 are investigated using mass spectrometry, Co-Immunoprecipitation, Dual-Luciferase Reporter Assay, and Chromatin Immunoprecipitation experiments. STC1 was found to enhance lung metastasis by promoting the recruitment and polarization of M2 macrophages, thereby fostering an immunosuppressive microenvironment. Mechanistically, STC1 competes with YAP for binding to βPIX within the KER domain in melanoma cells, leading to YAP activation and subsequent CCL2 upregulation. CCL2-induced M2 macrophages secrete VEGFA, which enhances tumor vascularization and increases STC1 expression via the AKT signaling pathway in melanoma cells, establishing a pro-metastatic feedback loop. Notably, STC1-induced YAP activation increases PD-L1 expression, promoting immune evasion. Silencing STC1 enhances the efficacy of PD-1 immune checkpoint therapy in mice. This research elucidates STC1's role in melanoma metastasis and its complex interactions with tumor-associated macrophages, proposing STC1 as a potential therapeutic target for countering melanoma metastasis and augmenting the efficacy of PD-1 immunotherapy.

Regeneration in Mice of Injured Skin, Heart, and Spinal Cord by α-Gal Nanoparticles Recapitulates Regeneration in Amphibians.

The healing of skin wounds, myocardial, and spinal cord injuries in salamander, newt, and axolotl amphibians, and in mouse neonates, results in scar-free regeneration, whereas injuries in adult mice heal by fibrosis and scar formation. Although both types of healing are mediated by macrophages, regeneration in these amphibians and in mouse neonates also involves innate activation of the complement system. These differences suggest that localized complement activation in adult mouse injuries might induce regeneration instead of the default fibrosis and scar formation. Localized complement activation is feasible by antigen/antibody interaction between biodegradable nanoparticles presenting α-gal epitopes (α-gal nanoparticles) and the natural anti-Gal antibody which is abundant in humans. Administration of α-gal nanoparticles into injuries of anti-Gal-producing adult mice results in localized complement activation which induces rapid and extensive macrophage recruitment. These macrophages bind anti-Gal-coated α-gal nanoparticles and polarize into M2 pro-regenerative macrophages that orchestrate accelerated scar-free regeneration of skin wounds and regeneration of myocardium injured by myocardial infarction (MI). Furthermore, injection of α-gal nanoparticles into spinal cord injuries of anti-Gal-producing adult mice induces recruitment of M2 macrophages, that mediate extensive angiogenesis and axonal sprouting, which reconnects between proximal and distal severed axons. Thus, α-gal nanoparticle treatment in adult mice mimics physiologic regeneration in amphibians. These studies further suggest that α-gal nanoparticles may be of significance in the treatment of human injuries.

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.

H3K18 lactylation-mediated VCAM1 expression promotes gastric cancer progression and metastasis via AKT-mTOR-CXCL1 axis

The role of the Immunoglobulin Superfamily (IgSF) as adhesion molecules in orchestrating inflammation is pivotal, yet its specific involvement in gastric cancer (GC) remains unknown. We analyzed IgSF components and discerned conspicuously elevated VCAM1 expression in GC, correlating with a poor prognosis. Remarkably, VCAM1 enhances GC cell proliferation and migration by activating AKT-mTOR signaling. Moreover, lactate in the tumor microenvironment (TME) promotes dynamic lactylation of H3K18 (H3K18la), leading to transcriptional activation of VCAM1 in GC cells. Furthermore, VCAM1 actively mediates intercellular communication in the TME. AKT-mTOR-mediated CXCL1 expression is increased by VCAM1, facilitating the recruitment of human GC-derived mesenchymal stem cells (hGC-MSCs), thereby fostering immunesuppression and accelerating cancer progression. In summary, H3K18 lactylation upregulated VCAM1 transcription, which activated AKT-mTOR signaling, and promoted tumor cell proliferation, EMT Transition and tumor metastasis. VCAM1 upregulated CXCL1 expression by AKT-mTOR pathway, so as to facilitate hGC-MSCs and M2 macrophage recruitment and infiltration. These findings provide novel therapeutic targets for GC.

Human Soluble TRAIL Secreted by Modified Lactococcus lactis Bacteria Promotes Tumor Growth in the Orthotopic Mouse Model of Colorectal Cancer.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) selectively induces apoptosis of sensitive cancer cells, including colorectal cancer (CRC). Due to its short biological half-life after intravenous administration and related clinical ineffectiveness, novel formulations of TRAIL need to be developed. Here we propose Lactococcus lactis bacteria as a vehicle for local delivery of human soluble TRAIL (hsTRAIL) in CRC. The use of common probiotics targeting guts as carriers for TRAIL could ensure its sustained release at the tumor site and extend the duration of its activity. We have already engineered hsTRAIL-secreting L.lactis bacteria and showed their effectiveness in elimination of human CRC cells in vitro and in vivo in a mouse subcutaneous model. Here, L.lactis(hsTRAIL+) were administered by gastric gavage to SCID mice with orthotopically developed HCT116 tumor in cecum, in monotherapy or in combination with metformin (MetF), already shown to enhance the hsTRAIL anti-tumor activity in subcutaneous CRC model. Oral administration of L.lactis(hsTRAIL+) resulted in significant progression of HCT116 tumors and shortening of the colon crypts. Secretion of hsTRAIL in the colon was accompanied by infiltration of the primary tumor with M2-macrophages, while MetF promoted transient colonization of the gut by L.lactis. Our study indicates that L.lactis bacteria after oral administration enable delivery of biologically active hsTRAIL to colon, however its potential therapeutic effect in CRC treatment is abolished by its pro-tumorigenic signalling, leading to the recruitment of M2-macrophages and tumor growth promotion.

Trichinella-derived protein ameliorates colitis by altering the gut microbiome and improving intestinal barrier function

BackgroundInflammatory bowel disease (IBD) encompasses Crohn’s Disease and Ulcerative Colitis. Reports have highlighted the potential use of helminths or their byproducts as a possible treatment for IBD; however, the mechanisms underlying their ability to modulate inflammation remain incompletely understood. In the present study, we analyze the possible mechanism of a serine protease inhibitor from adult T. spiralis excretion–secretion products (rTsSPI) on the improvement of colitis. MethodsThe immune protective effect of rTsSPI was studied by using DSS or Salmonella-induced colitis in female C56BL/6 mice. The effect of rTsSPI on the immune and inflammatory responses, gut microbiota, permeability of colon epithelium and junction proteins was analyzed. ResultsTreating mice with rTsSPI induced type 2 immunity and significantly attenuated clinical symptoms, macroscopical and histological features of DSS or bacteria-induced colonic inflammation. This was accompanied by decreasing neutrophil recruitment in the colonic lamina propria, and reducing TNF-α mRNA levels in the colon; in contrast, the recruitment of M2 macrophages, the expression level of IL-10 and adhesion molecules increased in the colon tissue. Moreover, treatment with rTsSPI led to an improvement in gut microbiota diversity, as well as an increase in the abundance of the bacterial genera Bifidobacterium and Ruminclostridium 5. ConclusionsCollective findings suggest that pretreatment with rTsSPI can ameliorate colitis in mice by inducing a Th2-type response with M2 macrophages. Data also indicate that immunotherapy with rTsSPI represents an additional strategy to ameliorate inflammatory processes in IBD by enhancing probiotic colonization and maintaining intestinal epithelial barrier function.

Bionic peptide scaffold in situ polarization and recruitment of M2 macrophages to promote peripheral nerve regeneration.

Tissue regeneration requires exogenous and endogenous signals, and there is increasing evidence that the exogenous microenvironment may play an even more dominant role in the complex process of coordinated multiple cells. The short-distance peripheral nerve showed a spontaneous regenerative phenomenon, which was initiated by the guiding role of macrophages. However, it cannot sufficiently restore long-distance nerve injury by itself. Based on this principle, we firstly constructed a proinflammatory model to prove that abnormal M2 expression reduce the guidance and repair effect of long-distance nerves. Furthermore, a bionic peptide hydrogel scaffold based on self-assembly was developed to envelop M2-derived regenerative cytokines and extracellular vesicles (EVs). The cytokines and EVs were quantified to mimic the guidance and regenerative microenvironment in a direct and mild manner. The bionic scaffold promoted M2 transformation in situ and led to proliferation and migration of Schwann cells, neuron growth and motor function recovery. Meanwhile, the peptide scaffold combined with CX3CL1 recruited more blood-derived M2 macrophages to promote long-distance nerve reconstruction. Overall, we systematically confirmed the important role of M2 in regulating and restoring the injury peripheral nerve. This bionic peptide hydrogel scaffold mimicked and remodeled the local environment for M2 transformation and recruitment, favoring long-distance peripheral nerve regeneration. It can help to explicate regulative effect of M2 may be a cause not just a consequence in nerve repair and tissue integration, which facilitating the development of pro-regenerative biomaterials.

Stress-induced β cell early senescence confers protection against type 1 diabetes

During the progression of type 1 diabetes (T1D), β cells are exposed to significant stress and, therefore, require adaptive responses to survive. The adaptive mechanisms that can preserve β cell function and survival in the face of autoimmunity remain unclear. Here, we show that the deletion ofthe unfolded protein response (UPR) genes Atf6α or Ire1αinβ cellsof non-obese diabetic (NOD) mice prior to insulitis generates a p21-driven early senescence phenotype and alters the β cell secretome that significantly enhances the leukemia inhibitory factor-mediated recruitment of M2 macrophages to islets. Consequently, M2 macrophages promote anti-inflammatory responses and immune surveillance that cause the resolution of islet inflammation, the removal of terminally senesced β cells, the reduction of β cell apoptosis, and protection against T1D. We further demonstrate that the p21-mediated early senescence signature is conserved in the residual β cells of T1D patients. Our findings reveal a previously unrecognized link between β cell UPR and senescence that, if leveraged, may represent a novel preventive strategy for T1D.

Role of exosome-mediated molecules SNORD91A and SLC40A1 in M2 macrophage polarization and prognosis of ESCC

BackgroundExosome-mediated interaction serves as a significant regulatory factor for M2 macrophage polarization in cancer.MethodsAll accessible data were acquired from The Cancer Genome Atlas (TCGA) database and analyzed using R software. Molecules implicated in exocrine secretion were amassed from the ExoCarta database. Our research initially quantified the immune microenvironment in Esophageal Squamous Cell Carcinoma (ESCC) patients based on the expression profile sourced from the TCGA database. Additionally, we delved into the biological role of M2 macrophages in ESCC via Gene Set Enrichment Analysis (GSEA).ResultsWe observed that patients with high M2 macrophage infiltration typically have a poorer prognosis. Subsequently, a total of 1457 molecules were identified, with 103 of these molecules believed to function through exocrine mechanisms, as supported by data from the ExoCarta database. SNORD91A and SLC40A1 were ultimately pinpointed due to their correlation with patient prognosis. Moreover, we investigated their potential roles in ESCC, including biological enrichment, immune infiltration, and genomic instability analysis.ConclusionsOur study identified exosome-associated molecules, namely SNORD91A and SLC40A1, which notably impact ESCC prognosis and local M2 macrophage recruitment, thereby presenting potential therapeutic targets for ESCC.

Tumor Growth Ameliorates Cardiac Dysfunction and Suppresses Fibrosis in a Mouse Model for Duchenne Muscular Dystrophy.

The interplay between heart failure and cancer represents a double-edged sword. Whereas cardiac remodeling promotes cancer progression, tumor growth suppresses cardiac hypertrophy and reduces fibrosis deposition. Whether these two opposing interactions are connected awaits to be determined. In addition, it is not known whether cancer affects solely the heart, or if other organs are affected as well. To explore the dual interaction between heart failure and cancer, we studied the human genetic disease Duchenne Muscular Dystrophy (DMD) using the MDX mouse model. We analyzed fibrosis and cardiac function as well as molecular parameters by multiple methods in the heart, diaphragm, lungs, skeletal muscles, and tumors derived from MDX and control mice. Surprisingly, cardiac dysfunction in MDX mice failed to promote murine cancer cell growth. In contrast, tumor-bearing MDX mice displayed reduced fibrosis in the heart and skeletal and diaphragm muscles, resulting in improved cardiac function. The latter is at least partially mediated via M2 macrophage recruitment to the heart and diaphragm muscles. Collectively, our data support the notion that the effect of heart failure on tumor promotion is independent of the improved cardiac function in tumor-bearing mice. Reduced fibrosis in tumor-bearing MDX mice stems from the suppression of new fibrosis synthesis and the removal of existing fibrosis. These findings offer potential therapeutic strategies for DMD patients, fibrotic diseases, and cardiac dysfunction.

Abstract P1080: Periostin Is Induced During Cell-based Repair In The Sheep Model Of Myocardial Infarction

Cardiac disease is the leading cause of death worldwide. Stem cell-based therapy may improve patient outcomes following a myocardial infarction. Our laboratory is studying the mechanistic basis by which neonatal Islet-1 positive cardiovascular progenitor cells (CPC) facilitate post infarct repair in the sheep model of myocardial infarction. Here, we addressed the hypothesis that periostin (POSTN) is induced in the cardiovascular repair zone following neonatal Islet-1+ cell-based repair. POSTN promotes cardiomyocyte proliferation, recruitment of M2 macrophages, epithelial-mesenchymal transition (EMT), migration, and angiogenesis. We examined human neonatal Islet-1+ cardiovascular progenitor cell clones isolated from several patients to initially determine whether or not POSTN was expressed in these cells. All clones expressed POSTN as shown by RT-PCR. The size of the amplified transcripts was confirmed by gel electrophoresis and POSTN expression in these clones was further confirmed by RNA sequencing. We then examined POSTN expression in the cardiovascular repair zone following myocardial infarction and cell transplantation in sheep. Sheep neonatal Islet-1+ CPC clones were used in this model of allogeneic cell-based repair. A myocardial infarction was induced in three Western sheep by left anterior descending coronary artery ligation. Ten million neonatal sheep Islet1+ cardiac progenitor cell clones isolated from 9 day old sheep were injected into the area surrounding the infarct site 3-4 weeks post infarction. RNA was isolated from the cardiovascular repair zone two months after cell injection. The non-infarcted region of the left ventricle and the left ventricle of normal, non-infarcted sheep were used as controls. POSTN transcripts were significantly elevated in the cell-treated cardiovascular repair zone of all three sheep, as identified by qRT-PCR relative to controls. Periostin levels were elevated between 6 and 255 fold in the repair zone relative to the non-infarcted region of the heart. Our data shows that POSTN is expressed in human Islet-1+ neonatal cardiovascular progenitor cells and that POSTN levels are induced during cell-based cardiovascular repair in the sheep model of myocardial infarction.

Blocking LTB4 signaling-mediated TAMs recruitment by Rhizoma Coptidis sensitizes lung cancer to immunotherapy

BackgroundImmune checkpoint blockade (ICB) induces durable immune responses across a spectrum of advanced cancers and revolutionizes the oncology field. However, only a subset of patients achieves long-lasting clinical benefits. Tumor-associated macrophages (TAMs) usually secrete immunosuppressive cytokines and contribute to the failure of ICB therapy. Therefore, it is crucial to mechanically manipulate the abundance and function of TAMs in the tumor microenvironment (TME), which can offer a promising molecular basis to improve the clinical response efficacy of ICB in cancer patients. PurposeThis study aims to investigate TAMs in the immunosuppressive microenvironment to identify new therapeutic targets, improve the ability to predict and guide responses to clinical immunotherapy, and develop new strategies for immunotherapy of lung tumors. MethodsLewis lung carcinoma (LLC) xenograft-bearing mouse models were established to analyze the antitumor activity of Rhizoma Coptidis (RC) in vivo. A systems pharmacology strategy was used to predict the correlation between RC and M2 macrophages. The effect of RC on the abundance of M2 macrophages was analyzed by flow cytometry of murine samples. Western blot was performed to analyze the expression of Leukotriene A4 hydrolase (LTA4H) and LTB4 receptor 1 (BLT1) in harvested lung cancer tissues. The impact of blocking leukotriene B4 (LTB4) signaling by RC on the recruitment of M2 macrophages was assessed in vitro and in vivo. Transwell migration assays were conducted to clarify the inhibition of macrophage migration by blocking LTB4. Lta4h−/− mice were used to investigate the sensitivity of immunotherapy to lung cancer by blocking the LTB4 signaling. ResultsHere, we report that RC, an herbal medicine from the family Ranunculaceae, suppresses the recruitment and immunosuppressive function of TAMs, which in turn sensitizes lung cancer to ICB therapy. Firstly, a systems pharmacology strategy was proposed to identify combinatorial drugs for ICB therapy with a systems biology perspective of drug-target-pathway-TME phenotype. We predicted and verified that RC significantly inhibits tumor growth and the infiltration of M2-TAMs into TME of LLC tumor-bearing mice. Then, RC inhibits the recruitment of macrophages to the tumor TME via blocking LTB4 signaling, and suppresses the expression of immunosuppressive factors (IL-10, TGF-β and VEGF). As a result, RC enables CD8+ T cells to retain their proliferative and infiltrative abilities within the TME. Ultimately, these events promote cytotoxic T-cell-mediated clearance of tumor cells, which is further enhanced by the addition of anti-PD-L1 therapy. Furthermore, we employed LTA4H deficient mice (Lta4h−/− mice) to evaluate the antitumor efficiency, the results showed that the efficacy of immunotherapy was enhanced due to the synergistic effect of LTB4 signaling blockage and ICB inhibition, leading to remarkable inhibition of tumor growth in a mouse model of lung adenocarcinoma. ConclusionsTaken together, these findings suggest that RC enhances antitumor immunity, providing a rationale for combining RC with immunotherapies as a potential anti-cancer treatment strategy.

RNA m5C methylation orchestrates BLCA progression via macrophage reprogramming.

Recently, epigenetics showed essential roles in tumour microenvironment (TME) and immunotherapy response, however, the functions of RNA 5-methylcytosine (m5C) modification in TME remains unknown. According to 13 m5C regulators, we evaluated 412 BLCA patients from The Cancer Genome Atlas (TCGA) database. The m5C score was constructed by unsupervised clustering analysis and principal component analysis (PCA) algorithms. Gene set variation analysis (GSVA), ESTIMATE algorithm, and immunohistochemical (IHC) staining were performed. Macrophage chemotaxis assay was used to assess the M2 macrophages. Among the 412 patients, the frequency of mutation was 13%. m5C regulators was expressed significantly in BLCA tissue compared with normal tissue. Then, two m5C methylation modification patterns were identified with dissimilar TME cell infiltration patterns. The C1 alteration pattern in the m5C cluster was connected with better survival. In addition, we found that NSUN6 was highly correlated with recruitment of macrophages via bioinformatics and IHC. Further experiment validated that NSUN6 promoted HDAC10 expression by mediating m5C methylation, inhibited the transcription of macrophage-associated chemokines and thus inhibited the recruitment of M2 macrophages. The m5C score constructed by m5C modification pattern showed that high m5C score group had a better prognosis. This study uncovered the significant roles of m5C modifications in modulating the TME and indicated that NSUN6 could inhibit the recruitment of M2 macrophages via m5C methylation, which provided novel insight into epigenetic regulation of TME and clinical suggestions for immunotherapeutic strategies.

Six-transmembrane epithelial antigen of prostate 3 (STEAP3) is a potential prognostic biomarker in clear cell renal cell carcinoma that correlates with M2 macrophage infiltration and epithelial-mesenchymal.

The six-transmembrane epithelial antigen of the prostate 3 (STEAP3) is a metalloreductase, which is essential for iron uptake. Existing literature has shown that STEAP3 may perform an important role in the onset and progression of tumors. Nonetheless, a complete pan-cancer investigation of the prognostic significance and immune properties of STEAP3 is currently unavailable. As part of our investigation into the possible functions of STEAP3 in malignancies, we conducted a comprehensive analysis to examine the prognostic value and immune features of STEAP3 in human pan-cancer. R and Cytoscape programs were applied to analyze and visualize the data. The expression of STEAP3 in both cell lines and tissues was measured utilizing a variety of approaches. Using the shRNA knockdown technique, we tested the viability of the A498 and 786-O cell lines and validated their functions. Both CCK-8 and transwell assays were conducted to estimate cell proliferation and invasion. The expression of STEAP3 was substantially elevated and was shown to be linked to prognosis in the majority of malignancies, notably in clear cell renal cell carcinoma (ccRCC). In addition, the expression of STEAP3 was shown to have a strong correlation with immune infiltrates, which in turn triggered the recruitment and polarization of M2 macrophages in ccRCC. The protein STEAP3 shows promise as a predictor of responses to immune-checkpoint blockade (ICB) therapy. Positive links between STEAP3 and the epithelial-mesenchymal transition (EMT), the p53 pathway, and the immune-associated pathways were also found in the enrichment analysis. Our results illustrated that the STEAP3 expression level was substantially elevated in ccRCC tissues and suggested that it could stimulate EMT in ccRCC by downregulating CDH1. In a diverse range of cancers, STEAP3 might serve as a biomarker for determining the prognosis as well as a predictor of immunotherapy responsiveness. STEAP3 is a novel biological marker for determining prognosis, and it also performs a remarkable function in the promotion of tumor growth in ccRCC by enhancing invasion and EMT, as well as by triggering the recruitment and polarization of M2 macrophages.

Tumor-derived exosome ElNF1-AS1 affects the progression of gastric cancer by promoting M2 polarization of macrophages.

This study attempted to investigate the role of exosome ELFN1-AS1 in gastric cancer (GC). The study used various techniques to determine the level of exosomal ELFN1-AS1 in GC tissue and cells, including quantitative real-time PCR. Pull-down assay and dual-luciferase reporter assay were employed to identify interactions between ELFN1-AS1 and miR-4644, as well as miR-4644 and PKM. Western blot was employed to explore the potential regulatory mechanism. Several in vitro assays were conducted in xenograft models to investigate the impacts of exosomal ELFN1-AS1 on GC development, metastasis and macrophage polarization. ELFN1-AS1 was upregulated in GC tissue and cells, with high enrichment in GC-derived exosomes. Exosomal ELFN1-AS1 enhances the cell abilities and stemness of GC. ELFN1-AS1 targeted and regulated miR-4644, which triggered PKM expression. Exosomal ELFN1-AS1 modulated glycolysis via PKM in an HIF-1α dependent manner in GC, promoting M2 polarization and macrophage recruitment. Furthermore, exosomal ELFN1-AS1 enhanced GC cell growth, metastasis and M2 polarization in vivo. The study suggests that ELFN1-AS1 could be a promising biomarker for the diagnosis and treatment of GC.

Mechanisms of traditional Chinese medicine formulas and active ingredients in regulation of macrophage subsets involved in inflammation and repair of coronary heart disease

Coronary artery disease(CAD) caused by atherosclerosis(AS) is a major contributor to the global burden of disease. The pathogenesis of CAD is complex, and the subset and function of cardiac macrophages are important factors affecting the occurrence and development of AS and the prognosis of CAD. Recent studies have shown that some traditional Chinese medicine(TCM) formulas and active ingredients can regulate macrophage subsets involved in the inflammation, injury, and repair process of CAD. This paper summarized the significant role of macrophages in AS and myocardial infarction. Based on the plasticity of macrophages, this paper elaborated that traditional Chinese medicine prevented and attenuated AS by regulating macrophage subsets, reducing the level of inflammatory factors, and promoting macrophage autophagy.Traditional Chinese medicine participated in the cardiac repair process after myocardial infarction by accelerating the recruitment of M2 macrophages, inhibiting the polarization of M1 macrophages mediated by glycolysis, inhibiting M1 macrophage-mediated cardiac nerve remodeling, and promoting M2 macrophage-mediated angiogenesis. In addition, in vitro studies on the regulation of macrophage subsets by the active ingredients of traditional Chinese medicine were also reviewed. It was pointed out that nuclear factor kappa B(NF-κB), adenosine 5'-monophosphate(AMP)-activated protein kinase(AMPK), phosphoinositide 3-kinase/protein kinase B(PI3K/Akt), chemokine(C-C motif) ligand 2/C-C chemokine receptor type 2(CCL2/CCR2) were the key targets and pathways for the regulation of macrophages by TCM.

Low-dose radiation therapy suppresses viral pneumonia by enhancing broad-spectrum anti-inflammatory responses via transforming growth factor-β production.

Low-dose radiation therapy (LDRT) can suppress intractable inflammation, such as that in rheumatoid arthritis, and is used for treating more than 10,000 rheumatoid arthritis patients annually in Europe. Several recent clinical trials have reported that LDRT can effectively reduce the severity of coronavirus disease (COVID-19) and other cases of viral pneumonia. However, the therapeutic mechanism of LDRT remains unelucidated. Therefore, in the current study, we aimed to investigate the molecular mechanism underlying immunological alterations in influenza pneumonia after LDRT. Mice were irradiated to the whole lung 1 day post-infection. The changes in levels of inflammatory mediators (cytokines and chemokines) and immune cell populations in the bronchoalveolar lavage (BALF), lungs, and serum were examined. LDRT-treated mice displayed markedly increased survival rates and reduced lung edema and airway and vascular inflammation in the lung; however, the viral titers in the lungs were unaffected. Levels of primary inflammatory cytokines were reduced after LDRT, and transforming growth factor-β (TGF-β) levels increased significantly on day 1 following LDRT. Levels of chemokines increased from day 3 following LDRT. Additionally, M2 macrophage polarization or recruitment was increased following LDRT. We found that LDRT-induced TGF-β reduced the levels of cytokines and polarized M2 cells and blocked immune cell infiltration, including neutrophils, in BALF. LDRT-induced early TGF-β production was shown to be a key regulator involved in broad-spectrum anti-inflammatory activity in virus-infected lungs. Therefore, LDRT or TGF-β may be an alternative therapy for viral pneumonia.

Abstract 2884: Cancer-associated fibroblasts potentiate subcutaneous tumor growth in a novel bladder cancer mouse model with a genotype dependency

Abstract Introduction Interrogation of the relationship of genotype (mutation in relevant gene) and phenotype (sensitivity to therapy) in targeted therapy would be facilitated by the use of isogenic in vitro and in vivo models. The PI3K/AKT/mTOR pathway is widely activated but heretofore untargeted in bladder cancer. We sought to develop an immunocompetent CRISPR-edited bladder cancer mouse model that recapitulates common PI3K/AKT/mTOR mutations to study a genotype-phenotype relationship. Our in vitro CRISPR-edited organoids are immunogenic in vivo, as such, we explored utilizing Cancer-Associated Fibroblasts (CAFs) to mediate immunosuppression and promote a pro-tumorigenic environment. Methods and Results We isolated bladder urothelial cells from Rosa26 LSL-Cas9/GFP transgenic mice and grew them as organoids. Trp53 and Rb1 were co-edited to establish ‘base organoids’. As proof of concept, Pten was edited in base organoids in anticipation of developing a series of organoids with different mTOR pathway genotypes. We found that Pten-KO base organoids were 9x more sensitive to ipatasertib than Pten WT organoids. The edited urothelial cells were engrafted into mouse bladder to further test kinase inhibitor susceptibility as preclinical evidence to support human clinical trials. However, the cells successfully engrafted but disappeared after 3-4 weeks before tumors formed. Subcutaneous allografts were also rejected after 3-4 weeks and showed CD45+ immune infiltration during rejection. When cells were injected subcutaneously with CAFs, tumors persisted for 12 weeks, but only in organoids with both Trp53 loss and loss of murine chromosome 4qC4 (which is homologous to 9p21 loss in humans). 9p21 contains 3 genes which are co-deleted in ~40% of bladder cancers: MTAP, CDKN2A, and CDKN2B. Histopathological analysis of these masses confirmed their malignant nature and revealed an immune-excluded architecture. IHC staining of 9p21/Trp53 KO tumors for CD206 and CD11c revealed greater recruitment of M2 macrophages than M1 macrophages. Conclusions CAFs remodel the tumor-microenvironment in bladder cancer via the recruitment of pro-tumorigenic M2 macrophages. This may occur in a genotype-specific manner and 9p21 loss may be a requirement for some genotypes to be tumorigenic. Citation Format: Henkel Lee Valentine, Uttam Satyal, Alexander Metz, Laura Bukavina, Philip H. Abbosh. Cancer-associated fibroblasts potentiate subcutaneous tumor growth in a novel bladder cancer mouse model with a genotype dependency [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2884.

High expression of SPINT2 promotes immune infiltration and tumor progression in ovarian cancer

This study aimed to identify the function and mechanism of Serine Peptidase Inhibitor, Kunitz Type 2 (SPINT2) in ovarian cancer (OC). The expression of SPINT2 was analyzed using the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) database. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to identify enriched functional categories of SPINT2 and its correlated genes. Correlation of SPINT2 with OC immune infiltration level was analyzed using the Tumor IMmune Estimation Resource (TIMER) web server. The effect of SPINT2 on cell proliferation was detected using cell counting kit-8 (CCK-8) and colony formation assay. Its effects on cell migration and invasion were examined using the transwell assay. Function of SPINT2 in M2 macrophage recruitment was detected using the migration assay. The role of SPINT2 on M2 macrophage differentiation was evaluated using M2 macrophage markers and by detection of interleukin 10 (IL-10) release. An OC cohort study (GSE12470) showed that SPINT2 was highly expressed in OC. The high SPINT2 expression was related to shorter overall survival (OS) and poor recurrence-free survival (RFS). GO and KEGG analysis indicated that SPINT2 associated genes played roles in glycoprotein catabolism, cell adhesion and T cell differentiation. SPINT2 also played a key role in infiltration of macrophages in OC. shSPINT2 reduced viability and colony formation ability of ovarian cancer cell line SK-OV-3 cells. Moreover, shSPINT2 also inhibited the cell migration and invasion. Co-culture of shSPINT2 transfected SK-OV-3 cells with macrophages inhibited the migration of M2 macrophages, and inhibited macrophages polarization from M0 to M2. These results suggested that SPINT2 is involved in infiltration of tumor-associated macrophages (TAMs). SPINT2 also plays an important role in the polarization and migration of macrophages. These findings suggested that SPINT2 has the potential to be explored as a biomarker for OC and a potential target.

Evaluation of cutaneous immune response in a controlled human in vivo model of mosquito bites

Mosquito-borne viruses are a growing global threat. Initial viral inoculation occurs in the skin via the mosquito ‘bite’, eliciting immune responses that shape the establishment of infection and pathogenesis. Here we assess the cutaneous innate and adaptive immune responses to controlled Aedes aegypti feedings in humans living in Aedes-endemic areas. In this single-arm, cross-sectional interventional study (trial registration #NCT04350905), we enroll 30 healthy adult participants aged 18 to 45 years of age from Cambodia between October 2020 and January 2021. We perform 3-mm skin biopsies at baseline as well as 30 min, 4 h, and 48 h after a controlled feeding by uninfected Aedes aegypti mosquitos. The primary endpoints are measurement of changes in early and late innate responses in bitten vs unbitten skin by gene expression profiling, immunophenotyping, and cytokine profiling. The results reveal induction of neutrophil degranulation and recruitment of skin-resident dendritic cells and M2 macrophages. As the immune reaction progresses T cell priming and regulatory pathways are upregulated along with a shift to Th2-driven responses and CD8+ T cell activation. Stimulation of participants’ bitten skin cells with Aedes aegypti salivary gland extract results in reduced pro-inflammatory cytokine production. These results identify key immune genes, cell types, and pathways in the human response to mosquito bites and can be leveraged to inform and develop novel therapeutics and vector-targeted vaccine candidates to interfere with vector-mediated disease.