CD68 Macrophages Research Articles

#5664 PERITONEAL DIFFUSE PODOPLANIN EXPRESSION IS ASSOCIATED WITH SEVERE ARTERIOLOPATHY IN CHILDREN ON PERITONEAL DIALYSIS

Abstract Background and Aims Podoplanin is a transmembrane glycoprotein binding chemokines and modulating inflammatory reactions. In healthy peritoneum, it is expressed in mesothelial cells and in lymphatic endothelium, expression beyond these structures (diffuse podoplanin staining, DPS) has been observed in adult patients with encapsulating peritoneal sclerosis (EPS). Method Parietal peritoneal tissues from 71 children on PD fluids with low glucose degradation product (GDP) content underwent digital histomorphometry. DPS and pathomechanisms of peritoneal membrane transformation and vasculopathy were hierarchically clustered. A panel of 13 peritoneal cell markers was selected and tissue sections were stained with metal conjugated antibodies and acquired using imaging mass cytometry (IMC; Hyperion Imaging System®). After single-cell segmentation, spillover correction, and normalization, cell types were identified using manual gating to train a random forest classifier for final cell type identifications using published workflows. Single-cell analysis was used to characterize peritoneal cells with positive podoplanin signals. Results DPS was present in 22% of the PD patients, all devoid of any clinical, radiological or histological feature of EPS. DPS positive patients were younger, had higher dialytic glucose exposure (median 103 vs. 154 g/m²/day, p = 0.002), and lower peritoneal arteriolar lumen to vessel (L/V) ratio, i.e. exhibited more arteriolar lumen narrowing. PD duration [median 20 (14.5, 48) months] and peritonitis incidence were similar as in non-DPS patients. In multivariable analysis, glucose exposure, PD duration, epithelial-to-mesenchymal transformed (EMT) cells and lower patient body surface area (BSA) independently predicted the presence of DPS. DPS and lower mesothelial surface coverage predicted lower arteriolar L/V ratio. In subgroups matched for BSA, PD duration and dialytic glucose exposure, DPS patients had a lower L/V ratio, (0.44 ± 0.13 vs. 0.31 ± 0.18, p = 0.003) and higher submesothelial CD45 leucocyte, CD68 macrophage and EMT cell count. Submesothelial lipopolysaccharide and hyaluronic acid receptor CD44 were increased in DPS positive patients, hyaluronan synthase 1 and 2 were similar. Among DPS positive patients, DPS intensity grade was higher in those with history of bacterial or fungal peritonitis (7 out of 15). Two patients had three and four peritonitis episodes respectively, their DPS pattern did not differ from patients with history of only one peritonitis episode. Hierarchical clustering demonstrated highest similarity of DPS positive areas with CD68 positive areas. In IMC analysis of DPS positive areas, highest podoplanin signals were derived from M2 classified macrophages (CD68+CD163+) and fibroblastic cells [αSMA positive/non-endothelial/non-macrophage (αSMA+PROX1-CD31-CD68-CD163-)], signals derived from M1 classified macrophages (CD68+CD163-) were lowest. Conclusion Peritoneal DPS in pediatric patients on low-GDP PD is associated with lower BSA, higher dialytic glucose exposure, history of infectious peritonitis and peritoneal inflammatory and EMT cell invasion, and predicts obliterating peritoneal vasculopathy. We identified M2 macrophages as major source of extra-lymphatic peritoneal podoplanin accumulation, suggesting their role in severe peritoneal transformation.

Single-cell and spatial transcriptomics to analyze radiation therapy-induced tumor microenvironment reshaping in HPV- cervical cancer.

e17528 Background: Radiotherapy (RT) is the most widely used conventional first-line treatment in cervical cancer (CC). However, the treatment response rate was only 10%-40%, and even lower in HPV- negative CC (HPV- CC). So far, previous knowledge of radiotherapy on tumor and tumor immune microenvironment (TME) remodeling is still insufficient. In this study, we aimed to comprehensively understand the dynamic change of tumor and TME of HPV- CC at the single-cell level. Methods: The single-cell and spatial transcriptome sequencing (STRNAseq) were used to analyze the TME of newly diagnosed HPV- CC tumor tissues, including pre-radiotherapy and 3 weeks after radiotherapy. Tissue samples were split into two parts, the freshly lysed single-cell suspension for 10X single-cell sequencing, and another part that was immediately processed into frozen and embedded for STRNAseq. Cell clustering, annotation and Single-cell sequencing and spatial transcriptome integration were analyzed by Seurat 4.0. The CNV of epithelial cells (ECs) was estimated by InferCNV. Results: A total of 14000 cells were obtained from paired HPV-CC patient samples (pre-RT and 3 weeks after RT) and clustered into 21 cell subsets. Six EC subsets, four fibroblast subsets, three macrophage subsets, two T cell subsets, two B cell subsets, one mast cell cluster, and an endothelial cell cluster were discovered. CNV analysis revealed that all ECs were malignantly proliferating tumor cells. Tumor cells accounted for 90% of the total tumor tissue prior to RT, but only less than 1% of tumor cells remain after RT. Fibroblasts and myeloid cells, which make up 60% of tumor tissue, increase significantly after radiotherapy, with myeloid cells accounting for nearly 50% of the total. Furthermore, we found a population of cells in the Post-RT sample that were both highly expressed CD14 and CD68 (macrophage biomarkers) and highly expressed COL1A2 (fibroblast biomarker). Differential analysis showed that this group of cells was down-regulated in Focal adhesion and ECM-receptor interaction pathways, while up-regulated in cytokine secretion and phagosome pathways, indicating that this group of cells might remodel the intercellular matrix and interacted with other cells to regulate the immune microenvironment. Integrating single-cell and spatial transcriptome data, fibroblasts and myeloid cells formed a tight co-distribution in tissues after radiotherapy, implying that their interaction is critical for the formation of the tumor immune microenvironment. Conclusions: This study comprehensively analyzed the dynamic change of tumor and TME of HPV- CC treated with RT at the single-cell transcriptional scale. After radiotherapy, fibroblasts and myeloid cells significantly increased and were highly heterogeneous, and the interaction between them is critical in forming a tumor ecosystem for radiotherapy.

Potential predictive biomarker for response to radiotherapy and CXCL12 inhibition in glioblastoma in the phase I/II GLORIA trial.

2048 Background: Standard of care (SOC) treatment achieves poor clinical outcomes in patients with glioblastoma (GBM), particularly in the absence of MGMT promoter hypermethylation. Preclinical models suggest that GBM recurrence is facilitated by CXCL12-mediated recruitment of bone marrow-derived cells capable of vasculogenesis after radiotherapy (RT). We have recently reported favorable safety and feasibility data of the phase I/II GLORIA trial, which combines RT and the CXCL12-neutralizing L-RNA aptamer olaptesed pegol (NOX-A12) in patients with newly diagnosed, incompletely resected or unresected GBM lacking MGMT promoter hypermethylation (NCT04121455). Here we report on clinical outcomes and their correlation with potential biomarkers. Methods: 10 patients with newly diagnosed incompletely resected (n=8) or biopsied (n=2) GBM with ECOG≤2, age≥18 and without MGMT promoter hypermethylation were enrolled. All patients received standard RT (60 Gy in 30 fractions or 40.05 Gy in 15 fractions) and escalating dose levels of continuous (24/7) i.v. infusions of NOX-A12 for 26 weeks. While the previously reported primary endpoint was safety, secondary efficacy endpoints included progression-free survival (PFS) and overall survival (OS). Biomarker assessment was performed with a six-plex immunofluorescence staining (CODEX) of neuropathologically confirmed tumor areas of pretreatment tissues for CXCL12, CD31 (endothelial cells), GFAP (glioma cells), CD68 (macrophages, microglia), aSMA (pericytes), Ki-67 (proliferating cells) and a nuclear marker. An independent patient cohort treated with SOC (n=15) matched by clinical and histopathological features was used for comparisons of efficacy and biomarker assessment. Results: Median PFS of the GLORIA cohort was 5.7 (range 1.9–8.5) months and the median OS was 12.7 (4.7–18.4) months. Biomarker analyses revealed that a higher frequency of CXCL12 expressing endothelial and glioma cells (EG12 score) significantly correlated with PFS (r=0.87; p=0.005) in patients treated with RT and NOX-A12, but not with SOC (r=-0.10; p=0.724). GLORIA patients with a high EG12 score (median classifier) had a significantly longer PFS than those with lower scores (3.0 vs. 6.0 months; p=0.031) and a trend towards prolonged OS (11.1 vs. 15.8 months; p=0.075). These correlations were not seen in the reference cohort treated with SOC (PFS: 6.0 vs. 4.6 months; p=0.502; OS: 10.0 vs. 9.6 months; p=0.243). Conclusions: We show superior clinical efficacy of RT and NOX-A12 in patients with high frequency of CXCL12 expressing endothelial and glioma cells, suggesting the use of the EG12 score as a novel predictive biomarker for CXCL12-directed therapies in GBM. Clinical trial information: NCT04121455 .

Polydatin protects against atherosclerosis by activating autophagy and inhibiting pyroptosis mediated by the NLRP3 inflammasome.

Polydatin is a bioactive ingredient extracted from the roots of the Reynoutria japonica Houtt, and it is a natural precursor of resveratrol. Polydatin is a useful inhibitor of inflammation and acts as a regulator of lipid metabolism. However, the specific mechanisms of action of polydatin in atherosclerosis (AS) remains poorly explained. The aim of this study was to assess the efficacy of polydatin on inflammation induced by the inflammatory cell death and autophagy in AS. Apolipoprotein E knockout (ApoE-/-) mice were fed with a high-fat diet (HFD) for 12 weeks to induce the formation of atherosclerotic lesions. The ApoE-/- mice were then randomly divided into the following six groups: (1) model group, (2) simvastatin group, (3) MCC950 group, (4) low dose polydatin group (Polydatin-L), (5) medium dose polydatin group (Polydatin-M), (6) and high dose polydatin group (Polydatin-H). The C57BL/6J mice were treated as controls and administered a standard chow diet. All mice were gavaged once daily for 8 weeks. The distribution of aortic plaques was observed by En Oil-red-O staining and hematoxylin and eosin staining (H&E). Oil-red-O staining was used to observe lipid content in the aortic sinus plaque; Masson trichrome staining was used to gauge collagen content in the plaque; and immunohistochemistry was used to evaluate smooth muscle actin (α-SMA) and CD68 macrophages marker expression levels in the plaque, which were used to assess the vulnerability index of the plaque. The lipid levels were measured using an enzymatic assay with an automatic biochemical analyzer. The level of inflammation was detected by enzyme-linked-immunosorbent assay (ELISA). Autophagosomes were detected by transmission electron microscopy (TEM). Pyroptosis was detected by terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL)/caspase-1 and other proteins related to the expression levels of autophagy and pyroptosis were detected by Western blot analysis. Nucleotide oligomerization (NOD)-like receptor (NLR) family pyrin domain-containing protein 3 (NLRP3) inflammasome activation leads to pyroptosis, including the cleavage of caspase-1, interleukin (IL)-1β and IL-18 production, and the co-expression of TUNEL/caspase-1-all of these are inhibited by polydatin, whose inhibitory effect is similar to that of MCC950, a specific inhibitor of NLRP3. Further, polydatin decreased the protein expression of NLRP3 and the phosphorylated mammalian target of rapamycin (p-mTOR), and increased the number of autophagosomes as well as the increased the cytoplasmic microtubule-associated protein light chain 3 (LC3)/autophagosome membrane-type LC3 ratio. Moreover, the protein expression levels of p62 decreased, suggesting that polydatin can increase autophagy. Polydatin can inhibit the activation of the NLRP3 inflammasome and cleavage of caspase-1, thereby inhibiting pyroptosis and secretion of inflammatory cytokines, and promoting autophagy through NLRP3/mTOR pathway in AS.

Novel Histopathological Biomarkers in Prostate Cancer: Implications and Perspectives.

Prostate cancer (PCa) is the second most frequently diagnosed cancer in men. Despite the significant progress in cancer diagnosis and treatment over the last few years, the approach to disease detection and therapy still does not include histopathological biomarkers. The dissemination of PCa is strictly related to the creation of a premetastatic niche, which can be detected by altered levels of specific biomarkers. To date, the risk factors for biochemical recurrence include lymph node status, prostate-specific antigen (PSA), PSA density (PSAD), body mass index (BMI), pathological Gleason score, seminal vesicle invasion, extraprostatic extension, and intraductal carcinoma. In the future, biomarkers might represent another prognostic factor, as discussed in many studies. In this review, we focus on histopathological biomarkers (particularly CD169 macrophages, neuropilin-1, cofilin-1, interleukin-17, signal transducer and activator of transcription protein 3 (STAT3), LIM domain kinase 1 (LIMK1), CD15, AMACR, prostate-specific membrane antigen (PSMA), Appl1, Sortilin, Syndecan-1, and p63) and their potential application in decision making regarding the prognosis and treatment of PCa patients. We refer to studies that found a correlation between the levels of biomarkers and tumor characteristics as well as clinical outcomes. We also hypothesize about the potential use of histopathological markers as a target for novel immunotherapeutic drugs or targeted radionuclide therapy, which may be used as adjuvant therapy in the future.

Clinical features of cardiac sarcoidosis in a cohort treated with epi- and endocardial VT ablation

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Clinical presentation of cardiac sarcoidosis is a chamaeleon. Detection of granuloma in the histopathology proofs the diagnosis of sarcoidosis, however myocardial biopsy is associated with a high sampling error. However, a prompt immune suppressive therapy would influence the patient’s prognosis significantly. Analyzing our cohort of epicardial (and endocardial) VT ablation respectively we intend to identify additional markers supporting the diagnosis sarcoidosis. Method In the last 4 years 130 patients (mean age 49 y, 63 % male ) were hospitalized for epicardial (and endocardial) VT ablation. 19 patients had the diagnosis sarcoidosis or were newly diagnosed. Mean follow up time was 4,3 a. ECG criteria, primary manifestation, histological findings, therapy, history of VT ablation, distribution of scar in MRI and anatomical mapping, PET CT findings, presence of atrial tachycardias, valve disease and comorbidities were documented. Results 6 of 15 (40 %) patients showed right bundle block , 6 of 19 (31 %) had AV nodal disease, 4 patients primarily presented with AV-block III, 14 patients (73 %) primarily presented themselves with ventricular arrhythmias (3 with cardiac arrest), in 93 % patients biopsy revealed elevated CD 68 macrophages and CD 3 T- lymphocytes, 6 of 16 were positive for granuloma (37,5 %). All patients were treated with steroids, 13 patients with a combination of immune suppressive therapy. All were treated with VT ablation, mean 2 ablations per patient. 6 of 6 (100 %) patients showed positive PET CT. Analyzing the scar distribution the most common locations in the 17 segment model were segment 2,3,4 and 5 and septal RV. (septal substrate in 66 %). There was a high correlation between the scar findings in the MRI and the anatomical mapping. No patient died during follow up, 1 patient had high urgent transplant after withdrawal of the steroids. Statistical analysis (Kendall-Tau-b) found a significant correlation between presence of CD3 Lymphocytes, fibrosis, VT as primary manifestation, the presence of ICD, positive PET-CT and septal substrate. Conclusion Patients presenting with ventricular arrhythmias combined with a positive PET CT, elevated CD3 T lymphocytes and CD68 macrophages in the biopsy and septal substrate are suspective of sarcoidosis and immune suppressive therapy should be considered. Further data are warranted to proof that observation and to differentiate from other cardiac diseases.

Enoxaparin sodium bone cement plays an anti-inflammatory immunomodulatory role by inducing the polarization of M2 macrophages

ObjectiveThe implantation of PMMA bone cement results in an immune response and the release of PMMA bone cement particles causes an inflammatory cascade. Our study discovered that ES-PMMA bone cement can induce M2 polarization of macrophages, which has an anti-inflammatory immunomodulatory effect. We also delved into the molecular mechanisms that underlie this process.MethodsIn this study, we designed and prepared samples of bone cement. These included PMMA bone cement samples and ES-PMMA bone cement samples, which were implanted into the back muscles of rats. At 3, 7, and 14 days after the operation, we removed the bone cement and a small amount of surrounding tissue. We then performed immunohistochemistry and immunofluorescence to observe the polarization of macrophages and the expression of related inflammatory factors in the surrounding tissues. The RAW264.7 cells were exposed to lipopolysaccharide (LPS) for 24 h to establish the macrophage inflammation model. Then, each group was treated with enoxaparin sodium medium, PMMA bone cement extract medium, and ES-PMMA bone cement extract medium, respectively, and cultured for another 24 h. We collected cells from each group and used flow cytometry to detect the expressions of CD86 and CD206 in macrophages. Additionally, we performed RT-qPCR to determine the mRNA levels of three markers of M1 macrophages (TNF-α, IL-6, iNOS) and two M2 macrophage markers (Arg-1, IL-10). Furthermore, we analyzed the expression of TLR4, p-NF-κB p65, and NF-κB p65 through Western blotting.ResultsThe immunofluorescence results indicate that the ES-PMMA group exhibited an upregulation of CD206, an M2 marker, and a downregulation of CD86, an M1 marker, in comparison to the PMMA group. Additionally, the immunohistochemistry results revealed that the levels of IL-6 and TNF-α expression were lower in the ES-PMMA group than in the PMMA group, while the expression level of IL-10 was higher in the ES-PMMA group. Flow cytometry and RT-qPCR analyses revealed that the expression of M1-type macrophage marker CD86 was significantly elevated in the LPS group compared to the NC group. Additionally, M1-type macrophage-related cytokines TNF-α, IL-6, and iNOS were also found to be increased. However, in the LPS + ES group, the expression levels of CD86, TNF-α, IL-6, and iNOS were decreased, while the expression of M2-type macrophage markers CD206 and M2-type macrophage-related cytokines (IL-10, Arg-1) were increased compared to the LPS group. In comparison to the LPS + PMMA group, the LPS + ES-PMMA group demonstrated a down-regulation of CD86, TNF-α, IL-6, and iNOS expression levels, while increasing the expression levels of CD206, IL-10, and Arg-1. Western blotting results revealed a significant decrease in TLR4/GAPDH and p-NF-κB p65/NF-κB p65 in the LPS + ES group when compared to the LPS group. Additionally, the LPS + ES-PMMA group exhibited a decrease in TLR4/GAPDH and p-NF-κB p65/NF-κB p65 levels when compared to the LPS + PMMA group.ConclusionES-PMMA bone cement is more effective than PMMA bone cement in down-regulating the expression of the TLR4/NF-κB signaling pathway. Additionally, it induces macrophages to polarize towards the M2 phenotype, making it a crucial player in anti-inflammatory immune regulation.Graphical

Association between endometrial senescent cells and immune cells in women with repeated implantation failure.

The aim of this study was to compare women with recurrent implantation failure (RIF) and control group in terms of the associations between p16-positive senescent cells and certain types of immune cells in human endometrium during the mid-luteal phase METHODS: Immunohistochemical staining was performed in 116 endometrial biopsies taken from 57 women presenting RIF, and control group of 59 women who became pregnant after the first intracytoplasmic sperm injection. Endometrial tissue sections were stained immunohistochemically for p16 (Senescent cells), CD4 (T-helpers), CD8 (T-killers), CD14 (Monocytes), CD68 (Macrophages), CD56 (Natural killers), and CD79α (B-cells). The percentage of positively stained cells for each marker was calculated by HALO image analysis software. The quantity and the relationship between senescent cells and immune cells were assessed and compared between the two groups. The correlation coefficient was highest between senescent cells and CD4+ cells and was lowest between senescent cells and CD14+ cells in RIF women, similarly to the control group. However, most of the observed correlations among senescent and immune cells weaken notably or disappear in the RIF group. When comparing senescent cell-to-immune cell quantitative ratios, only p16+/CD4+ cell ratio was significantly higher in RIF women as compared with patients from the control group. Our study indicates that the quantity of senescent cells in human endometrium during the mid-luteal phase has the strongest association with the amount of T helpers. Moreover, the specificity of this association might have an important impact on the occurrence of RIF.

Inhibition of the mevalonate pathway causes accumulation of CD14 in the endoplasmic reticulum of macrophages

Abstract Mevalonate kinase deficiency (MKD) is an autoinflammatory disease caused by mutations in the mevalonate kinase enzyme, which acts early in the mevalonate pathway to produce sterol and non-sterol isoprenoid compounds. Patients with MKD have episodes of inflammatory symptoms accompanied by increased plasma levels of pro-inflammatory cytokines. CD14 is a receptor that binds to lipopolysaccharide (LPS) and induces the release of cytokines. Isoprenoid depletion was previously shown to increase cellular and decrease extracellular levels of CD14 in macrophages after LPS stimulation. The objective of this study is to characterize the cellular localization of CD14 following isoprenoid depletion. RAW 264.7 macrophages were treated with lovastatin to deplete isoprenoids and CD14 localization was examined using immunofluorescence and western blotting after LPS stimulation. CD14 co-localized with the endoplasmic reticulum (ER) protein calnexin following lovastatin treatment. To quantitate ER CD14, cell lysates were digested with endoglycosidase (Endo) H, which removes high mannose glycans found on ER proteins, but not complex glycans added in the Golgi apparatus. Western blot results showed that the level of Endo H sensitive CD14 was higher in lovastatin as compared to carrier-treated cells. Co-incubation of lovastatin-treated cells with mevalonate or geranylgeranyl pyrophosphate (GGPP), but not cholesterol, prevented the ER accumulation of CD14 indicating that GGPP depletion may cause this effect. Understanding how mevalonate pathway products contribute to protein trafficking in macrophages will expand our understanding of inflammatory diseases.

Phenotypic Analysis of Fibrogenic Monocyte/Macrophage Subsets in Acute Inflammatory Exacerbations of Lung Disease Driven by Mutant Surfactant Protein-C Expression

Abstract Acute inflammatory exacerbations (AIE) represent precipitous deteriorations of a number of chronic lung conditions, including pulmonary fibrosis (PF), COPD, and asthma. AIEs are marked by diffuse and persistent polycellular alveolitis that profoundly accelerate lung function decline and mortality. Excess monocyte mobilization during AIE, and their persistence in the lung are linked to poor disease outcome. Guided by clinical evidence, we have developed an inducible model of pulmonary fibrosis leveraging the PF-linked missense isoleucine to threonine mutation at position 73 [I73T] in the alveolar type-2 cell-restricted Surfactant Protein-C [SP-C] gene [SFTPC]. We have previously shown that ablation of CCR2+ monocytes was protective with respect to lung histopathology, mouse survival, and overall inflammation following SP-C mutant induction. Here we identify and phenotypically characterize resident and recruited monocytes/macrophages populations intervening during the initiation and progression of AIE-PF. Single cell sequencing shows pro-inflammatory and pro-fibrotic signatures originating from immature recruited clusters (itgax-itgam+ ccr2+ cx3cr1+)as well as activated macrophages (cd68+ itgax+ itgam+ arg1+)14 d after SP-C I73Tinduction. Using CellChat Explorer database, these cells were predicted to coordinate intense tgfb1, fn1/fibronectinand spp1/osteopontinsignaling. Together, these results provide a clear picture of the fibrogenic role of specific activated monocyte/macrophage subsets responding to alveolar epithelial stress. NIEHS R01ES032553 (AV); ALSAM Foundation for Research Initiatives Grant (AV)

Impacts of Porphyromonas gingivalis periodontitis on rheumatoid arthritis autoimmunity.

In RA patients' synovial sites, citrullinated RA-related antigens such as type II collagens, fibrin (ogen), vimentin, and α-enolase could be targeted by ACCPAs. Since ACCPA production can be initiated a long time before RA sign appearance, primary auto-immunization against these citrullinated proteins can be originated from extra-articular sites. It has been shown that there is a significant association between P. gingivalis periodontitis, anti- P. gingivalis antibodies, and RA. P. gingivalis gingipains (Rgp, Kgp) can degrade proteins such as fibrin and α-enolase into some peptides in the form of Arg in the C-terminal which is converted to citrulline by PPAD. Also, PPAD can citrullinate type II collagen and vimentins (SA antigen). P. gingivalis induces inflammation and chemoattraction of immune cells such as neutrophils and macrophages through the increase of C5a (gingipain C5 convertase-like activity) and SCFA secretion. Besides, this microorganism stimulates anoikis, a special type of apoptosis, and NETosis, an antimicrobial form of neutrophil death, leading to the release of PAD1-4, α-enolase, and vimentin from apoptotic cells into the periodontal site. In addition, gingipains can degrade macrophages CD14 and decrease their ability in apoptotic cell removal. Gingipains also can cleave IgGs in the Fc region and transform them into rheumatoid factor (RF) antigens. In the present study, the effects of P. gingivalis on rheumatoid arthritis autoimmune response have been reviewed, which could attract practical insight both in bench and clinic.

Prognostic value of macrophage vasculiform mimicry in the evaluation of uveal melanoma progression

Introduction Uveal melanoma (UM) is a malignant neoplasm of the vascular tract of the eye, prone to hematogenous metastasis, regardless of the type of treatment performed. Prediction and probability of UM metastasis is one of the main tasks of onco-ophthalmology. We decribed an alternative method of tumor blood supply due to the process of vasculo-like mimicry (VM) with the formation of pseudovascular structures of tumor cells is described. At the same time, the participation of the microenvironment in the processes of VM and metastasis is currently debatable and relevant.Purpose of the work was to evaluate the prognostic role of macrophage vasculiform mimicry in the progression of chorioid melanoma based on the histological and immunohistochemical characteristics of surgical material.Materials and methods The surgical material of choroidal melanoma after enucleation for the period 2013-2018 was studied. Histological, histochemical (PAS reaction) and immunohistochemical studies were carried out using markers CD68 (macrophages), CD 34, CD31, D2-40 for the purpose of qualitative and quantitative assessment of macrophages in the stroma of tumors, large vessels and pseudovessels in the tumor.Results The ability of macrophages to form vasculo-like spaces in choroidal melanoma has been discovered and described. In growth with macrometastases, more phage representatives are recorded than in tissue samples of non-metastasizing melanoma. the volume of the macroscopic mass of the ulcer and the growth rate of phages were registered as the inverse average in terms of the strength of the correlation. In group studies with metastases, an increase in the volume of pseudovascular volumes and the number of phages is recorded.Discussion The macrophage microenvironment in a tumor can play a dual role: antitumor and protumor. The ability of macrophages for VM in UM has been described. The results of our macrostudy confirm the protumor activity of phages and their important role in tumor metastasis.Conclusion In-depth study of the ways of pseudovascular space formation not only by the cells of the tumor itself, but also by its microenvironment, helps to open new directions in the study of predictors of UM metastasis and outline approaches to the development of new directions of anti-tumortherapy.

Astragaloside IV suppresses the migration and EMT progression of cervical cancer cells by inhibiting macrophage M2 polarization through TGFβ/Smad2/3 signaling

Cervical cancer (CC) is a gynecological malignant tumor worldwide. Astragaloside IV (AS-IV) has been found to exert antitumor effects on CC. In addition, M2-polarized macrophages, known as tumor-associated macrophages (TAMs), play an important role in promoting cancer cell growth and angiogenesis. Thus, we explored the association between the antitumor effect of AS-IV and macrophage polarization in CC. Flow cytometry, ELISA, and RT‒qPCR assays were applied to detect the levels of CD163, IL-10, TGFβ, and CD206 in M2 macrophages with or without AS-IV treatment. In addition, conditioned medium (CM) was collected from these M2 macrophages, and CC cells were then cultured in various CMs. Wound healing and transwell assays were used to assess the migratory ability of CC cells. In this study, we found that AS-IV significantly inhibited M2 polarization of macrophages, as shown by decreased CD163, IL-10, TGFβ, and CD206 expression. In addition, compared with CM from M2 macrophages, CM from AS-IV-treated M2 macrophages notably inhibited angiogenesis, migration, and epithelial-mesenchymal transition (EMT) in CC cells. Furthermore, compared with CM from M2 macrophages, CM from AS-IV-treated M2 macrophages markedly reduced p-Smad2 and p-Smad3 protein expression in CC cells, and these changes were reversed by TGF-β treatment. Collectively, suppression of M2-like polarization of macrophages by AS-IV could prevent the migration and EMT of CC cells by inactivating TGF-β/Smad2/3 signaling. These findings might provide some theoretical support for exploring novel treatments for CC.

Adventitial Vasa Vasorum Neovascularization in Femoral Artery of Type 2 Diabetic Patients with Macroangiopathy Is Associated with Macrophages and Lymphocytes as well as the Occurrence of Cardiovascular Events.

This study was conducted to assess the relationship between adventitial vasa vasorum neovascularization (VVn) in femoral artery of type 2 diabetic patients with macroangiopathy and the recruitment of macrophages and lymphocytes, and to relate the density of VVn to the occurrence of cardiovascular events. Femoral artery samples were obtained from amputation cases. A total of 55 type 2 diabetic patients with macroangiopathy, 15 autopsy cases with type 2 diabetes without atherosclerosis. Hematoxylin and eosin (H&E) staining to observe the histopathological features; Victoria blue staining to analyze the histological features; immunohistochemistry (CD34, CD68, CD20, and CD3) to determine the VVn density and the expression of macrophages, B lymphocytes, and T lymphocytes. Type 2 diabetic patients with macroangiopathy showed a higher mean adventitial VVn density in femoral artery (48.40 ± 9.39 no./mm2) than patients with type 2 diabetes without atherosclerosis (19.75 ± 6.28 no./mm2) (p < 0.01). In addition, the VVn density was positively associated with the expression of CD68 macrophages (r = 0.62, p < 0.01) and CD20 B lymphocytes (r = 0.59, p < 0.01). Type 2 diabetic patients with high VVn density showed more adverse cardiovascular events (27/35 vs. 8/20 events, p = 0.006). In multivariable analysis adjusted for main risk factors for cardiovascular disease, VVn was still independently associated with adverse cardiovascular events (p = 0.01). VVn density in type 2 diabetic patients with macroangiopathy is positively correlated with the adventitial immune-inflammatory cell numbers and the development of atherosclerotic lesions. Furthermore, VVn density is associated with adverse cardiovascular events.

Evaluation of a CD206-Targeted Peptide for PET Imaging of Macrophages in Syngeneic Mouse Models of Cancer.

Tumor-associated macrophages (TAMs) are large phagocytic cells that play numerous roles in cancer biology and are an important component of the relationship between immune system response and tumor progression. The peptide, RP832c, targets the Mannose Receptor (CD206) expressed on M2-like macrophages and is cross-reactive to both human and murine CD206. Additionally, it exhibits therapeutic properties through its ability to shift the population of TAMs from an M2-like (protumor) toward an M1-like phenotype (antitumor) and has demonstrated promise in inhibiting tumor resistance in PD-L1 unresponsive melanoma murine models. In addition, it has shown inhibition in bleomycin-induced pulmonary fibrosis through interactions with CD206 macrophages.1,2 Our work aims to develop a novel CD206 positron emission tomography (PET) imaging probe based on RP832c (Kd = 5.64 μM) as a direct, noninvasive method for the assessment of TAMs in mouse models of cancer. We adapted RP832c to incorporate the chelator DOTA to allow for radiolabeling with the PET isotope 68Ga (t1/2 = 68 min; ß+ = 89%). In vitro stability studies were conducted in mouse serum up to 3 h. The in vitro binding characteristics of [68Ga]RP832c to CD206 were determined by a protein plate binding assay and Surface Plasmon Resonance (SPR). PET imaging and biodistribution studies were conducted in syngeneic tumor models. Stability studies in mouse serum demonstrated that 68Ga remained complexed up to 3 h (less than 1% free 68Ga). Binding affinity studies demonstrated high binding of [68Ga]RP832c to mouse CD206 protein and that the binding of the tracer was able to be blocked significantly when incubated with a blocking solution of native RP832c. PET imaging and biodistribution studies in syngeneic tumor models demonstrated uptake in tumor and CD206 expressing organs of [68Ga]RP832c. A significant correlation was found between the percentage of CD206 present in each tumor imaged with [68Ga]RP832c and PET imaging mean standardized uptake values in a CT26 mouse model of cancer. The data shows that [68Ga]RP832c represents a promising candidate for macrophage imaging in cancer and other diseases.

Abstract 3445: Immune cells infiltration and activation are higher in breast cancers resistant to antiestrogen therapy

Abstract We investigated the tumor microenvironment (TME) in estrogen receptor positive (ER+) primary breast cancers from stage I-III patients treated with estrogen deprivation (ED, induced with letrozole) for 10-21 days. We used primary breast cancer biopsies, collected from 198 patients, to assess tumor-infiltrating lymphocytes (TILs), transcriptomic profiles, and TME composition. Diagnostic biopsy and surgical on-treatment tumor specimens were collected; Ki67, ERα, PR, and HER2 expression were measured using automated quantitative analysis (AQUA). Tumors were categorized as estrogen deprivation-sensitive (ED-S) or -resistant (ED-R) based on the natural log (ln) of the Ki67 score (ln ≤1.0 or ≤2.7% Ki67+ cells vs. ln ≥2.0 or ≥7.4%, respectively) in the on-treatment (surgical) biopsy. Scoring of stromal (s)TILs, using hematoxylin and eosin staining of on-treatment specimens, revealed that sTILs were elevated in ED-R compared to ED-S tumors (p&amp;lt;0.0001). We next constructed tissue microarrays (TMAs) of on-treatment tumor sections and performed cyclic immunofluorescence (CyCIF) with 38 antibodies, including markers of hormone receptors, immune cells, signaling pathways, proliferation, DAPI (nuclei), and others. We then segmented single cells from each tumor core and designated them as immune, cancer, or stromal cells based on expression of a set of markers. Briefly, cells that stained strongly for CD45 (leukocyte marker), and/or CD4 (T lymphocyte marker), or CD68 (macrophage marker) were considered immune cells. CD45/CD4/CD68-negative cells were categorized as tumor, if E-cadherin and/or cytokeratin-positive, or stromal cells, if -negative. To investigate the TME composition, we next assessed cell specific spatial enrichment by quantifying the expression of immune markers in the area immediately adjacent to each tumor cell. Relative to ED-S, ED-R samples exhibited higher CD45+ cells (p&amp;lt;0.0001) and higher CD8+ T cells (p=0.0329), while CD4+ T cells showed no difference. Conversely, immune-suppressive T-reg (CD4+FOXP3+) cells were enriched in the ED-S samples (p=0.0004). In addition, PD1, a marker for T cell exhaustion, was higher in the ED-S group (p=0.0004), as were CD68+ cells (p&amp;lt;0.0001). To confirm and expand upon these findings, RNA-sequencing was performed on the on-treatment tumor sections. Gene set enrichment analysis of hallmark gene signatures revealed that immune-related gene sets, such as “IFNα response”, “IFNɣ response”, “allograft rejection”, and “inflammatory response” were enriched in ED-R vs. ED-S tumors. In summary, our study shows that activated anti-tumor immune cells are enriched in the TME of ER+ breast tumors resistant to estrogen deprivation, whereas ED-sensitive tumors show a more immunosuppressed or immune cold milieu. These data suggest a potential causal link between antiestrogen treatment and modulation of antitumor immunity in ER+ breast cancers. Citation Format: Fabiana Napolitano, Dhivya R. Sudhan, Yunguan Wang, Paula I. González-Ericsson, Luigi Formisano, Kyung-Min Lee, Chang-Ching Lin, María Rosario Chica-Parrado, Hongli Ma, Nathaniel Evans, Alberto Servetto, Saurabh Mendiratta, Spencer Barnes, Yisheng V. Fang, Justin M. Balko, Gordon B. Mills, Marilyne Labrie, Ariella B. Hanker, Carlos L. Arteaga. Immune cells infiltration and activation are higher in breast cancers resistant to antiestrogen therapy [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 3445.

SMTP-44D Inhibits Atherosclerotic Plaque Formation in Apolipoprotein-E Null Mice Partly by Suppressing the AGEs-RAGE Axis

SMTP-44D has been reported to have anti-oxidative and anti-inflammatory reactions, including reduced expression of receptor for advanced glycation end products (RAGE) in experimental diabetic neuropathy. Although activation of RAGE with its ligands, and advanced glycation end products (AGEs), play a crucial role in atherosclerotic cardiovascular disease, a leading cause of death in diabetic patients, it remains unclear whether SMTP-44D could inhibit experimental atherosclerosis by suppressing the AGEs-RAGE axis. In this study, we investigated the effects of SMTP-44D on atherosclerotic plaque formation and expression of AGEs in apolipoprotein-E null (Apoe-/-) mice. We further studied here whether and how SMTP-44D inhibited foam cell formation of macrophages isolated from Apoe-/- mice ex vivo. Although administration of SMTP-44D to Apoe-/- mice did not affect clinical or biochemical parameters, it significantly decreased the surface area of atherosclerotic lesions and reduced the atheromatous plaque size, macrophage infiltration, and AGEs accumulation in the aortic roots. SMTP-44D bound to immobilized RAGE and subsequently attenuated the interaction of AGEs with RAGE in vitro. Furthermore, foam cell formation evaluated by Dil-oxidized low-density lipoprotein (ox-LDL) uptake, and gene expression of RAGE, cyclin-dependent kinase 5 (Cdk5) and CD36 in macrophages isolated from SMTP-44D-treated Apoe-/- mice were significantly decreased compared with those from saline-treated mice. Gene expression levels of RAGE and Cdk5 were highly correlated with each other, the latter of which was also positively associated with that of CD36. The present study suggests that SMTP-44D may inhibit atherosclerotic plaque formation in Apoe-/- mice partly by blocking the AGEs-RAGE-induced ox-LDL uptake into macrophages via the suppression of Cdk5-CD36 pathway.

KCa3.1 Promotes Proinflammatory Exosome Secretion by Activating AKT/Rab27a in Atrial Myocytes during Rapid Pacing.

The aim of this study was to investigate the role of the medium-conductance calcium-activated potassium channel (KCNN4, KCa3.1) in the secretion of proinflammatory exosomes by atrial myocytes. Eighteen beagles were randomly divided into the sham group (n = 6), pacing group (n = 6), and pacing+TRAM-34 group (n = 6). Electrophysiological data, such as the effective refractory period, atrial fibrillation (AF) induction, and AF duration, were collected by programmed stimulation. Atrial tissues were subjected to hematoxylin and eosin, Masson's trichrome, and immunofluorescence staining. The expression of KCa3.1 and Rab27a was assessed by immunohistochemistry and western blotting. The downstream signaling pathways involved in KCa3.1 were examined by rapid pacing or overexpressing KCNN4 in HL-1 cells. Atrial rapid pacing significantly induced electrical remodeling, inflammation, fibrosis, and exosome secretion in the canine atrium, while TRAM-34 (KCa3.1 blocker) inhibited these changes. Compared with those in control HL-1 cells, the levels of exosome markers and inflammatory factors were increased in pacing HL-1 cells. Furthermore, the levels of CD68 and iNOS in macrophages incubated with exosomes derived from HL-1 cells were higher in the pacing-exo group than in the control group. More importantly, KCa3.1 regulated exosome secretion through the AKT/Rab27a signaling pathway. Similarly, inhibiting the downstream signaling pathway of KCa3.1 significantly inhibited exosome secretion. KCa3.1 promotes proinflammatory exosome secretion through the AKT/Rab27a signaling pathway. Inhibiting the KCa3.1/AKT/Rab27a signaling pathway reduces myocardial tissue structural remodeling in AF.

Tumor-associated macrophages facilitate oral squamous cell carcinomas migration and invasion by MIF/NLRP3/IL-1β circuit: A crosstalk interrupted by melatonin

Invasion and migration are significant challenges for treatment of oral squamous cell carcinomas (OSCCs). Tumor-associated macrophages (TAMs) interact with cancer cells and are involved in tumor progression. Our recent study demonstrated that melatonin inhibits OSCC invasion and migration; however, the mechanism by which melatonin influences crosstalk between TAMs and OSCCs is poorly understood. In this study, a co-culture system was established to explore the interactions between human monocytic cells (THP-1 cells) and human tongue squamous cell carcinoma cells (SCC-15 cells). The results were verified using monocyte-derived macrophages (MDMs) isolated and differentiated from primary peripheral blood mononuclear cells. In vivo, assays were performed to confirm the anticancer effects of melatonin. SCC-15 cells co-cultured with THP-1 cells or MDMs exhibited increased migration and invasion, which was reversed by melatonin. Co-culture also increased the expression of macrophage migration inhibitory factor (MIF), CD40, CD163 and IL-1β, and these changes were also reversed by melatonin. Moreover, IL-1β secretion in THP-1 cells was MIF- and NLR family pyrin domain-containing 3 (NLRP3)-dependent, and treated with IL-1β enhanced the invasion and migration of SCC-15 cells. Furthermore, melatonin treatment significantly decreased tumor volumes and weights, and tumors from mice treated with melatonin had lower levels of MIF, NLRP3, and IL-1β than tumor from control mice. These results demonstrate that macrophages facilitate the progression of OSCCs by promoting the MIF/NLRP3/IL-1β signaling axis, which can be interrupted by melatonin. Therefore, melatonin could act as an alternative anticancer agent for OSCCs by targeting this signaling axis.

Assessment of the Macrophage Scavenger Receptor CD163 in Mediating Glaesserella parasuis Infection of Host Cells.

The macrophage CD163 surface glycoprotein is a member of the SRCR family class B, which has been identified as the key trigger in host-pathogen interactions, but its specific roles in sensing Glaesserella parasuis (G. parasuis) infection are largely unknown. Here, we investigated porcine CD163 in mediating the adhesion and immune response of G. parasuis using in vitro host-bacteria interaction models. CD163-overexpressing Chinese hamster ovary K1 cells (CHO-K1) showed obvious subcellular localization in the cytoplasm, especially in the cytomembrane. Although detection using scanning electron microscopy (SEM) confirmed the bacterial adhesion, there was no significant difference in the adhesion of G. parasuis to CHO-K1 cells between the presence and absence of CD163. In addition, similar results were observed in 3D4/21 cells. Meanwhile, bindings of G. parasuis to nine synthetic peptides, the bacterial binding motifs within SRCR domains of CD163, were weak based on a solid-phase adhesion assay and agglutination assay. Moreover, CD163 had no effect on the expression of G. parasuis-induced inflammatory cytokines (IL-6, INF-γ, IL-10, IL-4 and TGF-β) in CHO-K1 cells. In conclusion, these findings indicate that porcine CD163 plays a minor role in sensing G. parasuis infection.