VSIG4 expression on macrophages facilitates lung cancer development

The role of SPI1/VSIG4/THBS1 on glioblastoma progression through modulation of the PI3K/AKT pathway

INTRODUCTION

Glioblastoma multiforme (GBM) poses a significant challenge in terms of treatment due to its high malignancy, necessitating the identification of additional molecular targets. VSIG4, an oncogenic gene participates in tumor growth and migration in various cancer types. Nevertheless, the precise process through which VSIG4 facilitates the malignant progression of glioma remains to be elucidated.

OBJECTIVES

This research aims to explore the function and molecular mechanism involving VSIG4 in the malignant progression of glioma.

METHODS

The amount of VSIG4 was measured using qPCR, western blotting, and immunohistochemistry. Lentivirus infections were applied for upregulating or downregulating molecules within glioma cells. The incorporation of 5-ethynyl-20-deoxyuridine, Transwell, cell counting kit-8, and clone formation experiments, were applied to assess the biological functions of molecules on glioma cells. Dual luciferase reporter gene, RNA immunoprecipitation, and chromatin immunoprecipitation assays were used to explore the functional relationship among relevant molecules.

RESULTS

The upregulation of VSIG4 was observed in GBM tissues, indicating an adverse prognosis. Silencing VSIG4 in glioma cells resulted in a decrease in cell viability, invasion, proliferation, and tumorigenesis, an increase in cell apoptosis, and a stagnation in the cell cycle progression at the G0/G1 phase. Mechanistically, SPI1-mediated upregulation of VSIG4 expression led to binding between VSIG4 and THBS1 protein, ultimately facilitating the malignant progression of glioma cells through the activation of the PI3K/AKT pathway. The inhibited proliferative and invasive capabilities of glioma cells were reversed by overexpressing THBS1 following the knockdown of VSIG4.

CONCLUSION

Our findings provide evidence for the role of VSIG4 as an oncogene and reveal the previously unidentified contribution of the SPI1/VSIG4/THBS1 axis in the malignant progression of glioma. This signaling cascade enhances tumor growth and invasion by modulating the PI3K/AKT pathway. VSIG4 as a potential biomarker may be a viable strategy in the development of tailored molecular therapies for GBM.

Antibodies Targeting Human or Mouse VSIG4 Repolarize Tumor-Associated Macrophages Providing the Potential of Potent and Specific Clinical Anti-Tumor Response Induced across Multiple Cancer Types

V-set immunoglobulin domain-containing 4 (VSIG4) is a B7 family protein with known roles as a C3 fragment complement receptor involved in pathogen clearance and a negative regulator of T cell activation by an undetermined mechanism. VSIG4 expression is specific for tumor-associated and select tissue-resident macrophages. Increased expression of VSIG4 has been associated with worse survival in multiple cancer indications. Based upon computational analysis of transcript data across thousands of tumor and normal tissue samples, we hypothesized that VSIG4 has an important role in promoting M2-like immune suppressive macrophages and that targeting VSIG4 could relieve VSIG4-mediated macrophage suppression by repolarizing tumor-associated macrophages (TAMs) to an inflammatory phenotype. We have also observed a cancer-specific pattern of VSIG4 isoform distribution, implying a change in the functional regulation in cancer. Through a series of in vitro, in vivo, and ex vivo assays we demonstrate that anti-VSIG4 antibodies repolarize M2 macrophages and induce an immune response culminating in T cell activation. Anti-VSIG4 antibodies induce pro-inflammatory cytokines in M-CSF plus IL-10-driven human monocyte-derived M2c macrophages. Across patient-derived tumor samples from multiple tumor types, anti-VSIG4 treatment resulted in the upregulation of cytokines associated with TAM repolarization and T cell activation and chemokines involved in immune cell recruitment. VSIG4 blockade is also efficacious in a syngeneic mouse model as monotherapy as it enhances efficacy in combination with anti-PD-1, and the effect is dependent on the systemic availability of CD8+ T cells. Thus, VSIG4 represents a promising new target capable of triggering an anti-cancer response via multiple key immune mechanisms.

Exploiting tertiary lymphoid structures gene signature to evaluate tumor microenvironment infiltration and immunotherapy response in colorectal cancer

Background

Tertiary lymphoid structures (TLS) is a particular component of tumor microenvironment (TME). However, its biological mechanisms in colorectal cancer (CRC) have not yet been understood. We desired to reveal the TLS gene signature in CRC and evaluate its role in prognosis and immunotherapy response.

Methods

The data was sourced from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases. Based on TLS-related genes (TRGs), the TLS related subclusters were identified through unsupervised clustering. The TME between subclusters were evaluated by CIBERSORT and xCell. Subsequently, developing a risk model and conducting external validation. Integrating risk score and clinical characteristics to create a comprehensive nomogram. Further analyses were conducted to screen TLS-related hub genes and explore the relationship between hub genes, TME, and biological processes, using random forest analysis, enrichment and variation analysis, and competing endogenous RNA (ceRNA) network analysis. Multiple immunofluorescence (mIF) and immunohistochemistry (IHC) were employed to characterize the existence of TLS and the expression of hub gene.

Results

Two subclusters that enriched or depleted in TLS were identified. The two subclusters had distinct prognoses, clinical characteristics, and tumor immune infiltration. We established a TLS-related prognostic risk model including 14 genes and validated its predictive power in two external datasets. The model's AUC values for 1-, 3-, and 5-year overall survival (OS) were 0.704, 0.737, and 0.746. The low-risk group had a superior survival rate, more abundant infiltration of immune cells, lower tumor immune dysfunction and exclusion (TIDE) score, and exhibited better immunotherapy efficacy. In addition, we selected the top important features within the model: VSIG4, SELL and PRRX1. Enrichment analysis showed that the hub genes significantly affected signaling pathways related to TLS and tumor progression. The ceRNA network: PRRX1-miRNA (hsa-miR-20a-5p, hsa-miR-485-5p) -lncRNA has been discovered. Finally, IHC and mIF results confirmed that the expression level of PRRX1 was markedly elevated in the TLS- CRC group.

Conclusion

We conducted a study to thoroughly describe TLS gene signature in CRC. The TLS-related risk model was applicable for prognostic prediction and assessment of immunotherapy efficacy. The TLS-hub gene PRRX1, which had the potential to function as an immunomodulatory factor of TLS, could be a therapeutic target for CRC.

Single-cell transcriptomic analysis of decidual immune cell landscape in the occurrence of adverse pregnancy outcomes induced by Toxoplasma gondii infection

BACKGROUND

Toxoplasma gondii is an obligate intracellular parasite that can lead to adverse pregnancy outcomes, particularly in early pregnancy. Previous studies have illustrated the landscape of decidual immune cells. However, the landscape of decidual immune cells in the maternal-fetal microenvironment during T. gondii infection remains unknown.

METHODS

In this study, we employed single-cell RNA sequencing to analyze the changes in human decidual immune cells following T. gondii infection. The results of scRNA-seq were further validated with flow cytometry, reverse transcription-polymerase chain reaction, western blot, and immunofluorescence staining.

RESULTS

Our results showed that the proportion of 17 decidual immune cell clusters and the expression levels of 21 genes were changed after T. gondii infection. Differential gene analysis demonstrated that T. gondii infection induced the differential expression of 279, 312, and 380 genes in decidual NK cells (dNK), decidual macrophages (dMφ), and decidual T cells (dT), respectively. Our results revealed for the first time that several previously unknown molecules in decidual immune cells changed following infection. This result revealed that the function of maternal-fetal immune tolerance declined, whereas the killing ability of decidual immune cells enhanced, eventually contributing to the occurrence of adverse pregnancy outcomes.

CONCLUSIONS

This study provides valuable resource for uncovering several novel molecules that play an important role in the occurrence of abnormal pregnancy outcomes induced by T. gondii infection.

A clinical prognostic model of oxidative stress-related genes linked to tumor immune cell infiltration and the prognosis of ovarian cancer patients

Background

According to statistics, ovarian cancer (OV) is the most prevalent type of gynecologic malignancy and has the highest mortality rate of all gynecologic tumors. Although several studies have shown that oxidative stress (OS) contributes significantly to the onset and progression of cancer, the role of OS in OV needs to be investigated further. Thus, it is critical to comprehend the function of OS-related genes in OV.

Methods

In this study, all data related to the transcriptome and clinical status of the patients were retrieved from "The Cancer Genome Atlas" (TCGA) and "Gene Expression Omnibus" (GEO) databases. Using the unsupervised cluster analysis technique, all patients with OV were classified into two different subtypes (categories) based on the OS gene. All hub genes were screened using the weighted gene co-expression network analysis (WGCNA). Since the hub genes and the differentially expressed genes (DEGs) in both categories were found to intersect, the univariate Cox regression analysis was implemented. A multivariate Cox analysis was also performed to construct a novel clinical prognosis model, which was validated using data from the GEO cohort. In addition, the relationship between risk score and immune cell infiltration level was evaluated using CIBERSORT. Finally, qRT-PCR was used to confirm the expression of the genes used to construct the model.

Results

Two subtypes of OS were obtained. The findings indicated that OS-C1 had a better survival outcome than OS-C2. The results of WGCNA yielded 112 hub genes. For univariate COX regression analyses, 49 OS-related trait genes were obtained. Finally, a clinical prognostic model containing two genes was constructed. This model could differentiate between patients with OV having varying years of survival in the TCGA and GEO cohorts. The model risk score was verified as an independent prognostic indicator. According to the results of CIBERSORT, many tumor-infiltrating immune cells were found to be significantly related to the risk score. Furthermore, the results revealed that patients with low-risk OV in the CTLA4 treatment group had a high likelihood of benefiting from immunotherapy. qRT-PCR results also showed that the expression of MARVELD1 and VSIG4 was high in the OV samples.

Conclusions

Analysis of the results suggested that the newly developed model, which contained two characteristic OS-related genes, could successfully predict the survival outcomes of all patients with OV. The findings of this study could offer valuable information and insights into the refinement of personalized therapy and immunotherapy for OV in the future.

Aging-related biomarker discovery in the era of immune checkpoint inhibitors for cancer patients

Older patients with cancer, particularly those over 75 years of age, often experience poorer clinical outcomes compared to younger patients. This can be attributed to age-related comorbidities, weakened immune function, and reduced tolerance to treatment-related adverse effects. In the immune checkpoint inhibitors (ICI) era, age has emerged as an influential factor impacting the discovery of predictive biomarkers for ICI treatment. These age-linked changes in the immune system can influence the composition and functionality of tumor-infiltrating immune cells (TIICs) that play a crucial role in the cancer response. Older patients may have lower levels of TIICs infiltration due to age-related immune senescence particularly T cell function, which can limit the effectivity of cancer immunotherapies. Furthermore, age-related immune dysregulation increases the exhaustion of immune cells, characterized by the dysregulation of ICI-related biomarkers and a dampened response to ICI. Our review aims to provide a comprehensive understanding of the mechanisms that contribute to the impact of age on ICI-related biomarkers and ICI response. Understanding these mechanisms will facilitate the development of treatment approaches tailored to elderly individuals with cancer.

Exploring the immune microenvironment of osteosarcoma through T cell exhaustion-associated gene expression: a study on prognosis prediction

Background

Osteosarcoma is a highly aggressive type of bone cancer with a poor prognosis. In the tumor immune microenvironment, T-cell exhaustion can occur due to various factors, leading to reduced tumor-killing ability. The purpose of this study was to construct a prognostic model based on T-cell exhaustion-associated genes in osteosarcoma.

Methods

Patient data for osteosarcoma were retrieved from the TARGET and GEO databases. Consensus clustering was employed to identify two novel molecular subgroups. The dissimilarities in the tumor immune microenvironment between these subgroups were evaluated using the "xCell" algorithm. GO and KEGG analyses were conducted to elucidate the underlying mechanisms of gene expression. Predictive risk models were constructed using the least absolute shrinkage and selection operator algorithm and Cox regression analysis. To validate the prognostic significance of the risk gene expression model at the protein level, immunohistochemistry assays were performed on osteosarcoma patient samples. Subsequently, functional analysis of the key risk gene was carried out through in vitro experimentation.

Results

Four gene expression signatures (PLEKHO2, GBP2, MPP1, and VSIG4) linked to osteosarcoma prognosis were identified within the TARGET-osteosarcoma cohort, categorizing patients into two subgroups. The resulting prognostic model showed strong predictive capability, with area under the receiver operating characteristic curve (AUC) values of 0.728/0.740, 0.781/0.658, and 0.788/0.642 for 1, 3, and 5-year survival in both training and validation datasets. Notably, patients in the low-risk group had significantly higher stromal, immune, and ESTIMATE scores compared to high-risk counterparts. Additionally, a nomogram was developed, exhibiting high accuracy in predicting the survival outcome of osteosarcoma patients. Immunohistochemistry, Kaplan-Meier, and time-dependent AUC analyses consistently supported the prognostic value of the risk model within our osteosarcoma patient cohort. In vitro experiments provided additional validation by demonstrating that the downregulation of GBP2 promoted the proliferation, migration, and invasion of osteosarcoma cells while inhibiting apoptosis.

Conclusion

The current study established a prognostic signature associated with TEX-related genes and elucidated the impact of the pivotal gene GBP2 on osteosarcoma cells via in vitro experiments. Consequently, it introduces a fresh outlook for clinical prognosis prediction and sets the groundwork for targeted therapy investigations in osteosarcoma.

Construction and validation of a prognostic nine-gene signature associated with radiosensitivity in head and neck squamous cell carcinoma

Background

Radiotherapy is an effective treatment for head and neck squamous cell carcinoma (HNSCC), however how to predict the prognosis is not clear.

Methods

Here we collected 262 radiosensitivity-associated genes, screened and constructed a prognostic nine-gene risk model through univariate COX, lasso regression, stepwise regression and multivariate COX analysis for transcriptome and clinical information of HNSCC patients obtained from the cancer genome atlas (TCGA) and gene expression omnibus (GEO) databases.

Results

The reliability and robustness of the risk model were verified by receiver operating characteristic (ROC) curves, risk maps, and Kaplan-Meier (KM) curves analysis. Differences in immune cell infiltration and immune-related pathway enrichment between high-risk and low-risk subgroups were determined by multiple immune infiltration analyses. Meanwhile, the mutation map and the responses to immunotherapy were also differentiated by the prognostic nine-gene signature associated with radiosensitivity. These nine genes expression in HNSCC was verified in the Human Protein Atlas (HPA) database. After that, these nine genes expression was verified to be related to radiation resistance through in-vitro cell experiments.

Conclusions

All results showed that the nine-gene signature associated with radiosensitivity is a potential prognostic indicator for HNSCC patients after radiotherapy and provides potential gene targets for enhancing the efficacy of radiotherapy.

Comprehensive analyses for the coagulation and macrophage-related genes to reveal their joint roles in the prognosis and immunotherapy of lung adenocarcinoma patients

Purpose

This study aims to explore novel biomarkers related to the coagulation process and tumor-associated macrophage (TAM) infiltration in lung adenocarcinoma (LUAD).

Methods

The macrophage M2-related genes were obtained by Weighted Gene Co-expression Network Analysis (WGCNA) in bulk RNA-seq data, while the TAM marker genes were identified by analyzing the scRNA-seq data, and the coagulation-associated genes were obtained from MSigDB and KEGG databases. Survival analysis was performed for the intersectional genes. A risk score model was subsequently constructed based on the survival-related genes for prognosis prediction and validated in external datasets.

Results

In total, 33 coagulation and macrophage-related (COMAR) genes were obtained, 19 of which were selected for the risk score model construction. Finally, 10 survival-associated genes (APOE, ARRB2, C1QB, F13A1, FCGR2A, FYN, ITGB2, MMP9, OLR1, and VSIG4) were involved in the COMAR risk score model. According to the risk score, patients were equally divided into low- and high-risk groups, and the prognosis of patients in the high-risk group was significantly worse than that in the low-risk group. The ROC curve indicated that the risk score model had high sensitivity and specificity, which was validated in multiple external datasets. Moreover, the model also had high efficacy in predicting the clinical outcomes of LUAD patients who received anti-PD-1/PD-L1 immunotherapy.

Conclusion

The COMAR risk score model constructed in this study has excellent predictive value for the prognosis and immunotherapeutic clinical outcomes of patients with LUAD, which provides potential biomarkers for the treatment and prognostic prediction.

Dissection of key factors correlating with H5N1 avian influenza virus driven inflammatory lung injury of chicken identified by single-cell analysis

Chicken lung is an important target organ of avian influenza virus (AIV) infection, and different pathogenic virus strains lead to opposite prognosis. Using a single-cell RNA sequencing (scRNA-seq) assay, we systematically and sequentially analyzed the transcriptome of 16 cell types (19 clusters) in the lung tissue of chickens infected with H5N1 highly pathogenic avian influenza virus (HPAIV) and H9N2 low pathogenic avian influenza virus (LPAIV), respectively. Notably, we developed a valuable catalog of marker genes for these cell types. Compared to H9N2 AIV infection, H5N1 AIV infection induced extensive virus replication and the immune reaction across most cell types simultaneously. More importantly, we propose that infiltrating inflammatory macrophages (clusters 0, 1, and 14) with massive viral replication, pro-inflammatory cytokines (IFN-β, IL1β, IL6 and IL8), and emerging interaction of various cell populations through CCL4, CCL19 and CXCL13, potentially contributed to the H5N1 AIV driven inflammatory lung injury. Our data revealed complex but distinct immune response landscapes in the lung tissue of chickens after H5N1 and H9N2 AIV infection, and deciphered the potential mechanisms underlying AIV-driven inflammatory reactions in chicken. Furthermore, this article provides a rich database for the molecular basis of different cell-type responses to AIV infection.

Ethnicity-specific association between TERT rs2736100 (A > C) polymorphism and lung cancer risk: a comprehensive meta-analysis

The rs2736100 (A > C) polymorphism of the second intron of Telomerase reverse transcriptase (TERT) has been confirmed to be closely associated with the risk of Lung cancer (LC), but there is still no unified conclusion on the results of its association with LC. This study included Genome-wide association studies (GWAS) and case-control studies reported so far on this association between TERT rs2736100 polymorphism and LC to clarify such a correlation with LC and the differences in it between different ethnicities and different types of LC. Relevant literatures published before May 7, 2022 on 'TERT rs2736100 polymorphism and LC susceptibility' in PubMed, EMbase, CENTRAL, MEDLINE databases were searched through the Internet, and data were extracted. Statistical analysis of data was performed in Revman5.3 software, including drawing forest diagrams, drawing funnel diagrams and so on. Sensitivity and publication bias analysis were performed in Stata 12.0 software. The C allele of TERT rs2736100 was associated with the risk of LC (Overall population: [OR] = 1.21, 95%CI [1.17, 1.25]; Caucasians: [OR] = 1.11, 95%CI [1.06, 1.17]; Asians: [OR] = 1.26, 95%CI [1.21, 1.30]), and Asians had a higher risk of LC than Caucasians (C vs. A: Caucasians: [OR] = 1.11 /Asians: [OR]) = 1.26). The other gene models also showed similar results. The results of stratified analysis of LC patients showed that the C allele was associated with the risk of Non-small-cell lung carcinoma (NSCLC) and Lung adenocarcinoma (LUAD), and the risk of NSCLC and LUAD in Asians was higher than that in Caucasians. The C allele was associated with the risk of Lung squamous cell carcinoma (LUSC) and Small cell lung carcinoma(SCLC) in Asians but not in Caucasians. NSCLC patients ([OR] = 1.27) had a stronger correlation than SCLC patients ([OR] = 1.03), and LUAD patients ([OR] = 1.32) had a stronger correlation than LUSC patients ([OR] = 1.09).In addition, the C allele of TERT rs2736100 was associated with the risk of LC, NSCLC and LUAD in both smoking groups and non-smoking groups, and the risk of LC in non-smokers of different ethnic groups was higher than that in smokers. In the Asians, non-smoking women were more at risk of developing LUAD. The C allele of TERT rs2736100 is a risk factor for LC, NSCLC, and LUAD in different ethnic groups, and the Asian population is at a more common risk. The C allele is a risk factor for LUSC and SCLC in Asians but not in Caucasians. And smoking is not the most critical factor that causes variation in TERT rs2736100 to increase the risk of most LC (NSCLC, LUAD). Therefore, LC is a multi-etiological disease caused by a combination of genetic, environmental and lifestyle factors.

VSIG4 interaction with heparan sulfates inhibits VSIG4-complement binding

V-set and immunoglobulin domain-containing 4 (VSIG4) is a complement receptor of the immunoglobulin superfamily that is specifically expressed on tissue resident macrophages, and its many reported functions and binding partners suggest a complex role in immune function. VSIG4 is reported to have a role in immune surveillance as well as in modulating diverse disease phenotypes such as infections, autoimmune conditions, and cancer. However, the mechanism(s) governing VSIG4's complex, context-dependent role in immune regulation remains elusive. Here, we identify cell surface and soluble glycosaminoglycans, specifically heparan sulfates, as novel binding partners of VSIG4. We demonstrate that genetic deletion of heparan sulfate synthesis enzymes or cleavage of cell-surface heparan sulfates reduced VSIG4 binding to the cell surface. Furthermore, binding studies demonstrate that VSIG4 interacts directly with heparan sulfates, with a preference for highly sulfated moieties and longer glycosaminoglycan chains. To assess the impact on VSIG4 biology, we show that heparan sulfates compete with known VSIG4 binding partners C3b and iC3b. Furthermore, mutagenesis studies indicate that this competition occurs through overlapping binding epitopes for heparan sulfates and complement on VSIG4. Together these data suggest a novel role for heparan sulfates in VSIG4-dependent immune modulation.

VSIG4 Silencing Inhibits Glioblastoma Growth by Regulating the JAK2/STAT3 Pathway

Background

Glioblastoma (GBM) is the most common malignant primary brain tumour in adults. VSIG4 has been identified to be associated with GBM. We aimed to determine the downstream regulatory mechanisms of VSIG4 in GBM.

Methods

Differential expression of VSIG4 was analysed using GEPIA. The expression of VSIG4 was assessed by RT-qPCR and its downstream genes were screened by transcriptome sequencing. The expression of pyroptosis-related proteins and the JAK2/STAT3 pathway was measured by Western blotting. GBM cell viability, migration, and invasion were detected using CCK-8, scratch, and Transwell assays. The levels of pyroptosis-related factors were measured using ELISA. The effect of VSIG4 on GBM tumour growth in vivo was explored by constructing a xenograft tumour model.

Results

VSIG4 expression was upregulated in GBM. Functionally, silencing of VSIG4 inhibited proliferation, invasion, and migration of U251 and LN229 cells, and promoted pyroptosis. Mechanically, transcriptome sequencing revealed that the JAK2/STAT3 pathway might be a downstream regulator of VSIG4. Further studies proved that silencing of VSIG4 enhanced the expression of p-JAK2 and p-STAT3, and the JAK2/STAT3 pathway inhibitor relieved the suppression of VSIG4 silencing on GBM cell viability, invasion, and migration. Furthermore, in vivo experiments further validated that knockdown of VSIG4 inhibited the growth of GBM tumors.

Conclusion

In GBM, silencing VSIG4 promoted pyroptosis and inhibited tumor progression by regulating the JAK2/STAT3 signaling pathway.

Nontoxic Fluorescent Nanoprobes for Multiplexed Detection and 3D Imaging of Tumor Markers in Breast Cancer

Multiplexed fluorescent immunohistochemical analysis of breast cancer (BC) markers and high-resolution 3D immunofluorescence imaging of the tumor and its microenvironment not only facilitate making the disease prognosis and selecting effective anticancer therapy (including photodynamic therapy), but also provides information on signaling and metabolic mechanisms of carcinogenesis and helps in the search for new therapeutic targets and drugs. The characteristics of imaging nanoprobe efficiency, such as sensitivity, target affinity, depth of tissue penetration, and photostability, are determined by the properties of their components, fluorophores and capture molecules, and by the method of their conjugation. Regarding individual nanoprobe components, fluorescent nanocrystals (NCs) are widely used for optical imaging in vitro and in vivo, and single-domain antibodies (sdAbs) are well established as highly specific capture molecules in diagnostic and therapeutic applications. Moreover, the technologies of obtaining functionally active sdAb–NC conjugates with the highest possible avidity, with all sdAb molecules bound to the NC in a strictly oriented manner, provide 3D-imaging nanoprobes with strong comparative advantages. This review is aimed at highlighting the importance of an integrated approach to BC diagnosis, including the detection of biomarkers of the tumor and its microenvironment, as well as the need for their quantitative profiling and imaging of their mutual location, using advanced approaches to 3D detection in thick tissue sections. The existing approaches to 3D imaging of tumors and their microenvironment using fluorescent NCs are described, and the main comparative advantages and disadvantages of nontoxic fluorescent sdAb–NC conjugates as nanoprobes for multiplexed detection and 3D imaging of BC markers are discussed.

The biology of VSIG4: Implications for the treatment of immune-mediated inflammatory diseases and cancer

V-set and immunoglobulin domain containing 4 (VSIG4), a type I transmembrane receptor exclusively expressed in a subset of tissue-resident macrophages, plays a pivotal role in clearing C3-opsonized pathogens and their byproducts from the circulation. VSIG4 maintains immune homeostasis by suppressing the activation of complement pathways or T cells and inducing regulatory T-cell differentiation, thereby inhibiting the development of immune-mediated inflammatory diseases but enhancing cancer progression. Consequently, VSIG4 exhibits a potential therapeutic effect for immune-mediated inflammatory diseases, but also is regarded as a novel target of immune checkpoint inhibition in cancer therapy. Recently, soluble VSIG4, the extracellular domain of VSIG4, shed from the surface of macrophages, has been found to be a biomarker to define macrophage activation-related diseases. This review mainly summarizes recent new findings of VSIG4 in macrophage phagocytosis and immune homeostasis, and discusses its potential diagnostic and therapeutic usage in infection, inflammation, and cancer.

The Role of V-Set Ig Domain-Containing 4 in Chronic Kidney Disease Models

V-set Ig domain-containing 4 (VSIG4) regulates an inflammatory response and is involved in various diseases. However, the role of VSIG4 in kidney diseases is still unclear. Here, we investigated VSIG4 expression in unilateral ureteral obstruction (UUO), doxorubicin-induced kidney injury mouse, and doxorubicin-induced podocyte injury models. The levels of urinary VSIG4 protein significantly increased in the UUO mice compared with that in the control. The expression of VSIG4 mRNA and protein in the UUO mice was significantly upregulated compared with that in the control. In the doxorubicin-induced kidney injury model, the levels of urinary albumin and VSIG4 for 24 h were significantly higher than those in the control mice. Notably, a significant correlation was observed between urinary levels of VSIG4 and albumin (r = 0.912, p < 0.001). Intrarenal VSIG4 mRNA and protein expression were also significantly higher in the doxorubicin-induced mice than in the control. In cultured podocytes, VSIG4 mRNA and protein expressions were significantly higher in the doxorubicin-treated groups (1.0 and 3.0 μg/mL) than in the controls at 12 and 24 h. In conclusion, VSIG4 expression was upregulated in the UUO and doxorubicin-induced kidney injury models. VSIG4 may be involved in pathogenesis and disease progression in chronic kidney disease models.

Therapeutic modulation of V Set and Ig domain-containing 4 (VSIG4) signaling in immune and inflammatory diseases

Inflammation is the result of acute and chronic stresses, caused by emotional or physical trauma, or nutritional or environmental pollutants, and brings serious harm to human life and health. As an important cellular component of the innate immune barrier, the macrophage plays a key role in maintaining tissue homeostasis and promoting tissue repair by controlling infection and resolving inflammation. Several studies suggest that V Set and Ig domain-containing 4 is specifically expressed in tissue macrophages and is associated with a variety of inflammatory diseases. In this paper, we mainly summarize the recent research on V Set and Ig domain-containing 4 structures, functions, function and roles in acute and chronic inflammatory diseases, and provide a novel therapeutic avenue for the treatment of inflammatory diseases, including nervous system, urinary, respiratory and metabolic diseases.

IL2RA+VSIG4+ tumor-associated macrophage is a key subpopulation of the immunosuppressive microenvironment in anaplastic thyroid cancer

Extensive infiltration of tumor-associated macrophages was correlated poor prognosis in anaplastic thyroid cancer (ATC). However, the heterogeneity and characteristics of the ATC-associated macrophages (ATAMs) in ATC remain far from clear. We combined single-cell RNA-sequencing analysis and gene expression microarray datasets to assess the molecular signature of ATAMs. Compared with normal thyroid-associated macrophages (NTAMs), 778 differentially expressed genes (DEGs) significantly changed in ATAMs compared with NTAMs. These DEGs were correlated with oxidative phosphorylation (M2 phenotype) and phagocytosis (M1 phenotype). Moreover, ATAMs highly expressed pro-tumor genes associated with angiogenesis, fibrosis, metalloprotease activity, and metastasis. Notably, we identified one ATC-specific subset, IL2RA⁺ VSIG4⁺ ATAMs, co-expressed M1 and M2 markers. The infiltration of IL2RA⁺ VSIG4⁺ ATAMs showed strong correlation with BRAF and RAS signaling, and its high infiltration was associated with favorable prognosis in thyroid-cancer patients. IL2RA⁺ VSIG4⁺ ATAMs were associated with increased tumor-infiltrating lymphocytes (B cells, CD8⁺ T cells, Tregs). IL2RA⁺ VSIG4⁺ ATAMs interacted with CD8⁺ T cells and Tregs through immune checkpoints (such as LGALS9_HAVCR2), cytokines (such as CXCL10_CXCR3), and receptors (such as CSF1R_CSF1), thereby forming an immunosuppressive microenvironment. Multiplex immunohistochemistry staining and coculture experiment confirmed that ATC cancer cells were able to induce the polarization of IL2RA⁺ VSIG4⁺ ATAMs. Besides, we identified several novel ATC-specific immune checkpoint genes including the immunosuppressive molecule VSIG4, LAIR1, and LILRB2. Expression of VSIG4 was also significantly correlated with tumor-infiltrating lymphocytes (B cells, CD8⁺ T cells, Tregs). In conclusion, our study revealed an ATC-specific ATAM subset with bifunctional phenotype, which provided a comprehensive insight to delineate the molecular characteristics of ATC-associated macrophages.

Single-cell sequencing reveals the cell map and transcriptional network of sporadic vestibular schwannoma

In this study, based on three tumor samples obtained from patients with sporadic vestibular schwannoma, 32,011 cells were obtained by single-cell transcriptome sequencing, and 22,309 high-quality cells were obtained after quality control and double cells removal. Then, 18 cell clusters were obtained after cluster analysis, and each cluster was annotated as six types of cells. Afterward, an in-depth analysis was conducted based on the defined six cell clusters, including characterizing the functional characteristics of each cell subtype, describing the cell development and differentiation pathway, exploring the interaction between cells, and analyzing the transcriptional regulatory network within the clusters. Based on these four dimensions, various types of cells in sporadic vestibular schwannoma tumor tissues were described in detail. For the first time, we expanded on the functional state of cell clusters that have been reported and described Schwann cells in the peripheral nervous system, which have not been reported in previous studies. Combined with the data of sporadic vestibular schwannoma and normal tissues in the gene expression omnibus (GEO) database, the candidate biomarkers of sporadic vestibular schwannoma were explored. Overall, this study described the single-cell map of sporadic vestibular schwannoma for the first time, revealing the functional state and development trajectory of different cell types. Combined with the analysis of data in the GEO database and immunohistochemical verification, it was concluded that HLA-DPB1 and VSIG4 may be candidate biomarkers and potential therapeutic targets for patients with sporadic vestibular schwannoma.

V-Set and immunoglobulin domain containing (VSIG) proteins as emerging immune checkpoint targets for cancer immunotherapy

The development of immune checkpoint inhibitors is becoming a promising approach to fight cancers. Antibodies targeting immune checkpoint proteins such as CTLA-4 and PD-1 can reinvigorate endogenous antitumor T-cell responses and bring durable advantages to several malignancies. However, only a small subset of patients benefit from these checkpoint inhibitors. Identification of new immune checkpoints with the aim of combination blockade of multiple immune inhibitory pathways is becoming necessary to improve efficiency. Recently, several B7 family-related proteins, TIGIT, VSIG4, and VSIG3, which belong to the VSIG family, have attracted substantial attention as coinhibitory receptors during T-cell activation. By interacting with their corresponding ligands, these VSIG proteins inhibit T-cell responses and maintain an immune suppressive microenvironment in tumors. These results indicated that VSIG family members are becoming putative immune checkpoints in cancer immunotherapy. In this review, we summarized the function of each VSIG protein in regulating immune responses and in tumor progression, thus providing an overview of our current understanding of VSIG family members.

VSIG4 regulates macrophages polarization and alleviates inflammation through activating PI3K/AKT and inhibiting TLR4/NF-κB pathway in myocardial ischemia-reperfusion injury rats

Background

Myocardial infarction is the primary cause of high disability and mortality in patients with cardiovascular disease worldwide. The pathological process of myocardial ischemia/reperfusion (I/R) may trigger harmful inflammatory response and ultimately lead to serious cardiac dysfunction. The mechanism of myocardial repair post myocardial infarction has not been fully elucidated. The present study speculated that VSIG4 is related to the regulation of heart injury.

Methods

The myocardial I/R injury model was established in Sprague-Dawley (SD) rats. Before I/R operation, the viral solution containing AAV-NC or AAV-VSIG4 was intravenously injected into rats. Cardiac function indicators, mRNA expression, the apoptosis ratio of cardiomyocytes, myocardial infarct area, phenotype polarization of macrophage, and the protein expression of apoptosis or macrophage phenotype were measured.

Results

Myocardial I/R injury decreased the expression of VSIG4 and subsequently triggered myocardial apoptosis. The induction of AAV-VSIG4 produced a protective effect on general cardiac function and attenuated the I/R-induced cellular apoptosis in rats. Moreover, VSIG4 signaling might potentially modulate macrophage M1/M2-related inflammatory disorders via activation of PI3K/AKT and inhibition of TLR4/NF-κB expression.

Conclusion

In summary, the present study provided evidence that VSIG4 had cardiac protective role in myocardial I/R injury. More importantly, enhanced VSIG4 expression inhibited M1 polarization of macrophages by blocking TLR4/NF-κB activation, subsequently suppressing cardiomyocyte apoptosis. This finding provides vital insights into the role of VSIG4 in I/R injury and may provide a new target for I/R therapy.

Identification of a Signature for Predicting Prognosis and Immunotherapy Response in Patients with Glioma

Glioma is a deadly tumor that accounts for the vast majority of brain tumors. Thus, it is important to elucidate the molecular pathogenesis and potential diagnostic and prognostic biomarkers of glioma. In the present study, gene expression profiles of GSE2223 were obtained from the Gene Expression Omnibus (GEO) database. Core modules and hub genes related to glioma were identified using weighted gene coexpression network analysis (WGCNA) and protein-protein interaction (PPI) network analysis of differentially expressed genes (DEGs). After a series of database screening tests, we identified 11 modules during glioma progression, followed by six hub genes (RAB3A, TYROBP, SYP, CAMK2A, VSIG4, and GABRA1) that can predict the prognosis of glioma and were validated in glioma tissues by qRT-PCR. The CIBERSORT algorithm was used to analyze the difference of immune cell infiltration between the glioma and control groups. Finally, Identification VSIG4 for immunotherapy response in patients with glioma demonstrating utility for immunotherapy research.

Upregulation of VSIG4 in Type 2 Diabetic Kidney Disease

Fibrosis is the final common finding in patients with advanced diabetic kidney disease. V-set Ig domain containing 4 (VSIG4) is related to fibrosis in several diseases. It also contributes to fibrosis under high-glucose conditions in renal tubule cells. To determine the role of VSIG4 in type 2 diabetes, we examined VSIG4 expression in a type 2 diabetic animal model and podocyte. Urinary excretion of albumin and VSIG4 was significantly higher in db/db mice than in the control group. Urine VSIGs levels for 6 h were about three-fold higher in db/db mice than in db/m mice at 20 weeks of age: 55.2 ± 37.8 vs. 153.1 ± 74.3 ng, p = 0.04. Furthermore, urinary VSIG4 levels were significantly correlated with urinary albumin levels (r = 0.77, p < 0.01). Intrarenal VSIG4 mRNA expression was significantly higher in db/db mice than in control mice (1.00 ± 0.35 vs. 1.69 ± 0.77, p = 0.04). Further, VSIG4 expression was almost twice as high in db/db mice at 20 weeks of age. Intrarenal VSIG immunoreactivity in db/db mice was also significantly higher than that in control mice. In cultured podocytes, both high glucose and angiotensin II significantly upregulated the expression of VSIG4 mRNA and protein. In conclusion, VSIG4 was upregulated in an animal model of type 2 diabetes and was related to albuminuria and pro-fibrotic markers. Considering these relationships, VSIG4 may be an important mediator of diabetic nephropathy progression.

Comprehensive Analysis of PDLIM3 Expression Profile, Prognostic Value, and Correlations with Immune Infiltrates in Gastric Cancer

Protein PDZ and LIM domain 3 (PDLIM3) is a cytoskeletal protein, colocalizing with α-actinin on the Z line of mature muscle fibers. It plays a key role in dilated cardiomyopathy (DCM), muscular dystrophy, and tumor progression. However, correlations between PDLIM3 expression, prognosis, and tumor-infiltrating immune cells in gastric cancer are unknown. Therefore, we leveraged the Oncomine, GEPIA, GEO, and HPA databases to evaluate PDLIM3 expression in tumors. We also quantified PDLIM3 expression in 15 matched pairs of gastric tumor and nontumor tissues by immunohistochemistry. The Kaplan-Meier method was employed to determine the relationship between PDLIM3 expression and clinical outcomes. GO and KEGG analyses were performed to illuminate the molecular mechanisms of action of PDLIM3. TIMER2.0 and GEPIA were applied to investigate correlations between PDLIM3 expression and gene marker subsets signifying immune infiltration, with TIMER2.0 exploring the correlations between PDLIM3 and related signaling pathways. Gastric cancer tissues were found to express more PDLIM3 than nontumor tissues. PDLIM3 overexpression was associated with shorter OS and PFS of gastric cancer patients (OS $\text{HR}=2.02$ , $P=9.8\text{e}-10$ ; PFS $\text{HR}=1.77$ , $P=7.5\text{e}-06$ ). PDLIM3 was also positively correlated with worse OS and PFS according to gastric cancer staging, Her-2 overexpression, differentiation grade, and Lauren classification. PDLIM3 was shown to be associated with immunological responses by GO, while it was related to PI3K/Akt signal pathways by KEGG analysis. Furthermore, increased PDLIM3 expression was significantly correlated with greater infiltration of CD4+ T cells, CD8+ T cells, macrophages, neutrophils, and dendritic cells. PDLIM3 expression had significant positive correlations with a variety of immune marker subsets. Finally, correlations were found between PDLIM3 and crucial markers of signaling pathways involving PI3K/Akt and p38 MAPK. Thus, upregulation of PDLIM3 was significantly associated with poor prognosis, immune cell infiltration, and activation of two key signal pathways in gastric cancer. We propose that PDLIM3 could be used as a biomarker to predict prognosis and immune cell infiltration in gastric cancer.

VSIG4/CRIg directly regulates early CD8+ T cell activation through its counter-receptor in a narrow window

T-cell responses are fine-tuned by positive and negative co-signal molecules expressed on immune cells and adjacent tissues. VSIG4 is a newly identified member of the B7 family of ligands, which negatively regulates innate inflammatory and CD4⁺ T cell-mediated responses. However, little is known about the direct effects of VSIG4, which are exerted through an unidentified counter-receptor on CD8⁺ T cells. We investigated the binding of the VSIG4-Ig fusion protein during CD8⁺ T cell activation, and the functional involvement of VSIG4 pathway, using VSIG4-Ig and VSIG4-transfectants. VSIG4-Ig binding to CD8⁺ T cells was temporally observed in the CD44^high phenotype during initial activation. VSIG4-Ig binding was observed earlier than the induction of PD-1, LAG3, and TIM-3, which are immune checkpoint receptors for exhausted CD8⁺ T cells. Immobilized VSIG4-Ig inhibited anti-CD3/CD28 mAb-induced CD8⁺ T cell activation, as indicated by proliferation and IFN-γ production, similar to the downregulation of T-bet and Eomesodermin transcription factors. VSIG4 on FcγR⁺ P815 or specific antigen-presenting E.G7 cells inhibited the generation of effector CD8⁺ T cells, as indicated by proliferation, IFN-γ and TNF-α expression, and granule degradation, compared to parental cells. However, the window for the regulatory function of VSIG4 was narrow and dependent on the strength of TCR (and CD28)-mediated signals. Our results suggested that VSIG4 directly delivers co-inhibitory signals via an as-yet unidentified counter-receptor on activated CD8⁺ T cells. VSIG4-mediated CD8⁺ T cell tolerance might contribute to the steady-state maintenance of homeostasis.

Neutrophils Require Activation to Express Functional Cell-Surface Complement Receptor Immunoglobulin

The phagocytosis-promoting complement receptor, Complement Receptor Immunoglobulin (CRIg), is exclusively expressed on macrophages. It has been demonstrated that expression in macrophages could be modulated by inflammatory mediators, including cytokines. This raised the possibility that a major phagocyte, the neutrophil, may also express CRIg following activation with inflammatory mediators. Here we show that resting peripheral blood neutrophil lysates subjected to protein analysis by Western blot revealed a 35 kDa CRIg isoform, consistent with the expression of CRIg mRNA by RT-PCR. By flow cytometry, CRIg was detected intracellularly and in very minor amounts on the cell surface. Interestingly, expression on the cell surface was significantly increased to functional levels after activation with inflammatory mediators/neutrophil activators; N-Formylmethionine-leucyl-phenylalanine, tumor necrosis factor (TNF), Granulocyte-Macrophage Colony stimulating Factor (GM-CSF), bacterial lipopolysaccharide, leukotriene B4 and phorbol myristate acetate. The increase in expression required p38 MAP kinase and protein kinase C activation, as well as intracellular calcium. Neutrophils which were defective in actin microfilament reorganization due to a mutation in ARPC1B or inhibition of its upstream regulator, Rac2 lose their ability to upregulate CRIg expression. Inhibition of another small GTPase, Rab27a, with pharmacological inhibitors prevented the increase in CRIg expression, suggesting a requirement for the actin cytoskeleton and exocytosis. Engagement of CRIg on TNF-primed neutrophils with an anti-CRIg monoclonal antibody increased the release of superoxide and promoted the activation of p38 but not ERK1/ERK2 or JNK MAP kinases. The TNF-induced increase in killing of Staphylococcus aureus was blocked by the anti-CRIg antibody. Adding to the anti-microbial role of CRIg, it was found that GM-CSF priming lead to the release of neutrophil extracellular traps. Interestingly in contrast to the above mediators the anti-inflammatory cytokine IL-10 caused a decrease in basal expression and GM-CSF induced increase in CRIg expression. The data demonstrate that neutrophils also express CRIg which is regulated by inflammatory mediators and cytokines. The findings show that the neutrophil antimicrobial function involving CRIg requires priming as a means of arming the cell strategically with microbial invasion of tissues and the bloodstream.

Metabolism in tumor-associated macrophages

Macrophages functionally adapt to a diverse set of signals, a process that is critical for their role in maintaining or restoring tissue homeostasis. This process extends to cancer, where macrophages respond to a series of inflammatory and metabolic cues that direct a maladaptive healing response. Tumor-associated macrophages (TAMs) have altered glucose, amino acid, and lipid metabolic profiles, and interfering with this metabolic shift can blunt the ability of macrophages to promote tumor growth, metastasis, and the creation of an immunosuppressive microenvironment. Here we will review changes in metabolites and metabolic pathways in TAMs and link these with the phenotypic and functional properties of the cells. We will also discuss current strategies targeting TAM metabolism as a therapeutic intervention in cancer.

Rab18 interacted with V-set and immunoglobulin domain-containing 4 (VSIG4) to involve in the apoptosis of glioma and the sensitivity to temozolomide

Rab18 and V-set and immunoglobulin domain-containing 4 (VSIG4) were reportedly implicated in the malignant progression of glioma. In this study, their relationship was further explored, accompanied by the investigation into their effects on the sensitivity of temozolomide (TMZ). The proliferation and apoptosis of U87-MG and U251-MG were detected after Rab18 silencing through CCK8 assay and flow cytometry, respectively. The interaction between Rab18 and VSIG4 was predicted through database and verified by immunoprecipitation assay. The suspicion that whether the sensitivity of glioma to temozolomide was affected by the Rab18-VSIG4 interaction was explored through CCK8 assay. We observed decreased proliferation and increased apoptosis and TMZ sensitivity in U87-MG and U251-MG treated by siRNA-Rab18. Not only was the interaction predicted using database, but also it was confirmed by IP assay. Intriguingly, VSIG4 overexpression effectively reversed above biological process and TMZ sensitivity caused by Rab18 silencing. To conclude, the Rab18-VSIG4 interaction was implicated in the proliferation and apoptosis of glioma, as well as TMZ sensitivity. Targeting the interaction between Rab18 and VSIG4 may help exploit new therapies to enhance TMZ sensitivity for treating patients with glioma.

Profiles of immune cell infiltration and immune-related genes in the tumor microenvironment of esophageal squamous cell carcinoma

BACKGROUND

As a complex system participating in tumor development and progression, the tumor microenvironment was poorly understood in esophageal cancer especially squamous cell carcinoma (ESCC).

METHODS

ESTIMATE algorithm is used to investigate tumor-infiltrating immune cells and prognostic genes which were associated with the tumor microenvironment in ESCC.

RESULTS

Based on the immune and stromal scores, ESCC samples were divided into high and low score groups and 299 overlapping differentially expressed genes were identified. Functional enrichment analysis showed that these genes were mainly involved in muscle-related function. Prognostic genes including COL9A3, GFRA2, and VSIG4 were used to establish a risk prediction model using Cox regression analyses. Then multivariate analysis showed that COL9A3 was an independent discriminator of a better prognosis. Kaplan-Meier survival analysis showed that the expression of COL9A3 was significantly correlated with the overall survival of ESCC patients. The area under the curve for the risk model in predicting 1- and 3- year survival rates were 0.660 and 0.942, respectively. The risk score was negatively correlated with plasma cells, while positively correlated with the proportions of activated CD4 memory T cells, M1 Macrophages and M2 Macrophages (p < 0.001 for each comparison). Gene set enrichment analysis suggested that both immune response and immune system process gene sets were significantly enriched in high-risk group.

CONCLUSIONS

Our study provided a comprehensive understanding of the TME in ESCC patients. The establishment of the risk model is valuable for the early identification of high-risk patients to facilitate individualized treatment and improve the possibility of immunotherapy response.

Circadian rhythm-associated clinical relevance and Tumor Microenvironment of Non-small Cell Lung Cancer

Objective: We aimed to explore the prognostic implication for non-small cell lung cancer (NSCLC) based on the expression profiles of circadian clock-related genes (CCRGs), and describe the changes of immune infiltration and cell functions of related to the circadian rhythm.

Methods: Univariate and multivariate Cox proportional hazard regression were performed to determine a CCRGs risk-score significantly correlated with overall survival (OS) of the training set and validation set. GO, KEGG, and GSVA indicated discrepant changes in cellular processes and signaling pathways associated with these CCRGs. Immune cell infiltration and mutation rates were investigated by the online analysis platform and the algorithm provided by works of literature.

Results: The signature-based on ten-gene signatures could independently predict the OS both in TCGA lung adenocarcinoma (p < 0.001, HR: 1.228, 95% CI: 1.158 to 1.302) and lung squamous cell carcinoma (p < 0.001, HR: 2.501, 95% CI: 2.010 to 3.117), respectively. The circadian oscillations driven by CCRGs could disturb the metabolism and cellular functions of cancer cells. The infiltration level of critical cells in specific anti-tumor immunity process was suppressed apparently. In contrast, the infiltrating of inflammatory cells and immune cells with negative regulatory effects were promoted in the high-risk group. CCRGs were evolutionarily conserved with low mutation rates, which brought difficulties to explore therapeutic targets.

Conclusion: We identified and validated a circadian rhythm signature to described clinical relevance and tumor microenvironment of NSCLC, which revealed that circadian rhythms might play an influential role in the NSCLC.

Expression of the immune checkpoint molecule V-set immunoglobulin domain-containing 4 is associated with poor prognosis in patients with advanced gastric cancer

BACKGROUND

Recent clinical studies on immune checkpoint (IC) inhibitors in the context of advanced gastric cancer (AGC) have failed to show significant survival benefits but have suggested the possible role of IC inhibitors in anti-AGC immunity. Considering the low efficacy of targeted drugs in AGC, there is an urgent need for the discovery of new targets for the development of immunotherapeutics and prognostic markers for patient selection. This study aimed to investigate the expression of a new IC molecule, V-set Ig domain-containing 4 (VSIG4), and its clinical significance in AGC and other major cancers.

METHODS

We analyzed the expression of VSIG4 and its correlation with survival in various carcinomas, including 882 surgically resected samples from patients with stage II-III AGC (two academic hospitals).

RESULTS

VSIG4 positivity in AGC was significantly associated with overall survival (OS; Hazard ratio (HR) = 2.661, 95% confidence interval [CI] = 2.012-3.519, P < 0.001) and event-free survival (HR = 2.8, 95% CI = 2.18-3.72, P < 0.001). These findings were successfully validated in independent cohorts. VSIG4 expression was also significantly correlated with low intratumoral CD8 + T-cell infiltration (CD8i) (P = 0.029) and high Foxp3 + /CD8i ratio (P = 0.026), which is consistent with the previously reported immunological function of VSIG4. However, VSIG4 expression was not associated with survival in other cancers (colon, P = 0.459; lung, P = 0.275; kidney, P = 0.121; breast, P = 0.147).

CONCLUSION

Our results suggest that VSIG4 is an independent prognostic factor in AGC and also implies that VSIG4 is a second-tier IC molecule in AGC, thus, providing an important basis for the development of gastric cancer-specific immunotherapeutics.

CXCR1 correlates to poor outcomes of EGFR-TKI against advanced non-small cell lung cancer by activating chemokine and JAK/STAT pathway

OBJECTIVE

CXCR1, a member of the seven-transmembrane chemokine receptor family, promotes cell proliferation and metastasis in many tumors. The present study was undertaken to explore the interrelation between CXCR1 expression and the prognosis of advanced non-small cell lung cancer (NSCLC) in addition to the efficacy of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in lung adenocarcinoma (LUAD).

METHODS

The expression of CXCR1 in NSCLC tissues was assessed by immunohistochemistry. The relationships between CXCR1 expression and clinical-pathological factors were investigated. Concomitantly, the relationship between CXCR1 expression and EGFR-TKI treatment efficacy was investigated. Gene set enrichment analysis (GSEA) was employed for the exploration of pathway enrichment, tumor immune estimation resource (TIMER) and gene expression profiling interactive analysis (GEPIA) for the inspection of the interrelationship between infiltration immune cells and CXCR1. After gain-and loss-of-function of CXCR1 in NSCLC cells, qRT-PCR and Western blot were applied to measure the levels of proteins associated with the chemokine pathway (CCL3 and CXCL2) and the JAK/STAT pathway (IL9R, PIAS4 and STAT5A).

RESULTS

CXCR1 significantly correlated with poor prognosis of NSCLC patients. Additionally, CXCR1 limited the clinical efficacy of EGFR-TKIs in advanced LUAD (P = 0.029). In the tumor microenvironment, CXCR1 was positively associated with infiltration levels of immune markers in lung squamous cell carcinoma (LUSC) and LUAD. High expression of CXCR1 was implicated in the NOD-like receptor (NLR), cytokine/cytokine receptor, JAK/STAT and chemokine signaling pathways in LUAD and LUSC. Overexpression of CXCR1 in NSCLC cell lines enhanced expressions of CCL3, CXCL2, IL9R, PIAS4 and STAT5A, while knockdown of CXCR1 repressed expressions of CCL3, CXCL2, IL9R, PIAS4 and STAT5A.

CONCLUSION

CXCR1 is correlated with poor prognosis of NSCLC and affects the efficacy of EGFR-TKIs in LUAD.

VSIG4 Induces Epithelial-Mesenchymal Transition of Renal Tubular Cells under High-Glucose Conditions

High glucose-mediated tubular injury contributes to the development and progression of diabetic nephropathy through renal tubulointerstitial fibrosis. V-set immunoglobulin-domain-containing 4 (VSIG4), a B7 family-related protein, is a complement receptor. Although the role of epithelial–mesenchymal transition (EMT) has been reported in several diseases, little is known about its relationship with VSIG4 under diabetic conditions. This study aimed to investigate the role of VSIG4 in human tubule cells stimulated by high glucose (HG, 55 mM). HG upregulated both mRNA and protein levels of VSIG4 in proximal tubule cells (HK-2 cells) and Madin Darby Canine Kidney cells. These upregulations were accompanied by increased expression of mesenchymal markers such as fibronectin, N-cadherin, matrix metalloproteinase 9, and vimentin, and by decreased expression of the epithelial marker, E-cadherin. The siRNA-mediated inhibition of VSIG4 in HK-2 cells restored the dysregulation of EMT in cells. Interestingly, VSIG4 inhibition did not affect the expression of transforming growth factor (TGF)-β, whereas inhibition of TGF-β reduced VSIG4 expression, subsequently suppressing fibrosis markers. These findings suggest that VSIG4 plays an important role in mediating renal tubular EMT through the downstream action of HG-induced TGF-β activation.

A Recurrence-Specific Gene-Based Prognosis Prediction Model for Lung Adenocarcinoma through Machine Learning Algorithm

Background

After curative surgical resection, about 30-75% lung adenocarcinoma (LUAD) patients suffer from recurrence with dismal survival outcomes. Identification of patients with high risk of recurrence to impose intense therapy is urgently needed.

Materials and Methods

Gene expression data of LUAD were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Differentially expressed genes (DEGs) were calculated by comparing the recurrent and primary tissues. Prognostic genes associated with the recurrence-free survival (RFS) of LUAD patients were identified using univariate analysis. LASSO Cox regression and multivariate Cox analysis were applied to extract key genes and establish the prediction model.

Results

We detected 37 DEGs between primary and recurrent LUAD tumors. Using univariate analysis, 31 DEGs were found to be significantly associated with RFS. We established the RFS prediction model including thirteen genes using the LASSO Cox regression. In the training cohort, we classified patients into high- and low-risk groups and found that patients in the high-risk group suffered from worse RFS compared to those in the low-risk group (P < 0.01). Concordant results were confirmed in the internal and external validation cohort. The efficiency of the prediction model was also confirmed under different clinical subgroups. The high-risk group was significantly identified as the risk factor of recurrence in LUAD by the multivariate Cox analysis (HR = 13.37, P = 0.01). Compared to clinicopathological features, our prediction model possessed higher accuracy to identify patients with high risk of recurrence (AUC = 96.3%). Finally, we found that the G2M checkpoint pathway was enriched both in recurrent tumors and primary tumors of high-risk patients.

Conclusions

Our recurrence-specific gene-based prognostic prediction model provides extra information about the risk of recurrence in LUAD, which is conducive for clinicians to conduct individualized therapy in clinic.

Tumor-Associated Macrophages in Human Breast, Colorectal, Lung, Ovarian and Prostate Cancers

Tumor-associated macrophages (TAMs) are major innate immune cells that constitute up to 50% of the cell mass of human tumors. TAMs are highly heterogeneous cells that originate from resident tissue-specific macrophages and from newly recruited monocytes. TAMs' variability strongly depends on cancer type, stage, and intratumor heterogeneity. Majority of TAMs are programmed by tumor microenvironment to support primary tumor growth and metastatic spread. However, TAMs can also restrict tumor growth and metastasis. In this review, we summarized the knowledge about the role of TAMs in tumor growth, metastasis and in the response to cancer therapy in patients with five aggressive types of cancer: breast, colorectal, lung, ovarian, and prostate cancers that are frequently metastasize into distant organs resulting in high mortality of the patients. Two major TAM parameters are applied for the evaluation of TAM correlation with the cancer progression: total amount of TAMs and specific phenotype of TAMs identified by functional biomarkers. We summarized the data generated in the wide range of international patient cohorts on the correlation of TAMs with clinical and pathological parameters of tumor progression including lymphatic and hematogenous metastasis, recurrence, survival, therapy efficiency. We described currently available biomarkers for TAMs that can be measured in patients' samples (tumor tissue and blood). CD68 is the major biomarker for the quantification of total TAM amounts, while transmembrane receptors (stabilin-1, CD163, CD206, CD204, MARCO) and secreted chitinase-like proteins (YKL-39, YKL-40) are used as biomarkers for the functional TAM polarization. We also considered that specific role of TAMs in tumor progression can depend on the localization in the intratumoral compartments. We have made the conclusion for the role of TAMs in primary tumor growth, metastasis, and therapy sensitivity for breast, colorectal, lung, ovarian, and prostate cancers. In contrast to other cancer types, majority of clinical studies indicate that TAMs in colorectal cancer have protective role for the patient and interfere with primary tumor growth and metastasis. The accumulated data are essential for using TAMs as biomarkers and therapeutic targets to develop cancer-specific immunotherapy and to design efficient combinations of traditional therapy and new immunomodulatory approaches.

Immune checkpoint protein VSIG4 as a biomarker of aging in murine adipose tissue

Adipose tissue is recognized as a major source of systemic inflammation with age, driving age-related tissue dysfunction and pathogenesis. Macrophages (Mφ) are central to these changes yet adipose tissue Mφ (ATMs) from aged mice remain poorly characterized. To identify biomarkers underlying changes in aged adipose tissue, we performed an unbiased RNA-seq analysis of ATMs from young (8-week-old) and healthy aged (80-week-old) mice. One of the genes identified, V-set immunoglobulin-domain-containing 4 (VSIG4/CRIg), encodes a Mφ-associated complement receptor and B7 family-related immune checkpoint protein. Here, we demonstrate that Vsig4 expression is highly upregulated with age in perigonadal white adipose tissue (gWAT) in two mouse strains (inbred C57BL/6J and outbred NIH Swiss) independent of gender. The accumulation of VSIG4 was mainly attributed to a fourfold increase in the proportion of VSIG4+ ATMs (13%-52%). In a longitudinal study, VSIG4 expression in gWAT showed a strong correlation with age within a cohort of male and female mice and correlated strongly with physiological frailty index (PFI, a multi-parameter assessment of health) in male mice. Our results indicate that VSIG4 is a novel biomarker of aged murine ATMs. VSIG4 expression was also found to be elevated in other aging tissues (e.g., thymus) and was strongly induced in tumor-adjacent stroma in cases of spontaneous and xenograft lung cancer models. VSIG4 expression was recently associated with cancer and several inflammatory diseases with diagnostic and prognostic potential in both mice and humans. Further investigation is required to determine whether VSIG4-positive Mφ contribute to immunosenescence and/or systemic age-related deficits.

Impact of Immunometabolism on Cancer Metastasis: A Focus on T Cells and Macrophages

Despite improved treatment options, cancer remains the leading cause of morbidity and mortality worldwide, with 90% of this mortality correlated to the development of metastasis. Since metastasis has such an impact on treatment success, disease outcome, and global health, it is important to understand the different steps and factors playing key roles in this process, how these factors relate to immune cell function and how we can target metabolic processes at different steps of metastasis in order to improve cancer treatment and patient prognosis. Recent insights in immunometabolism direct to promising therapeutic targets for cancer treatment, however, the specific contribution of metabolism on antitumor immunity in different metastatic niches warrant further investigation. Here, we provide an overview of what is so far known in the field of immunometabolism at different steps of the metastatic cascade, and what may represent the next steps forward. Focusing on metabolic checkpoints in order to translate these findings from in vitro and mouse studies to the clinic has the potential to revolutionize cancer immunotherapy and greatly improve patient prognosis.

Immunoregulatory protein V-set and immunoglobulin domain-containing 4 is overexpressed in patients with endometriosis

AIM

V-set and immunoglobulin domain-containing 4 (VSIG4) is a potent negative regulator of T-cell responses and is suggested to regulate antitumor immunity. This study investigates whether VSIG4 is significantly expressed in endometriosis patients and the association between VSIG4 levels and serum cancer antigen (CA)-125 levels, VSIG4 levels and endometriosis severity.

METHODS

Tumor tissues and peripheral blood samples were obtained during surgery from 42 endometriotic cyst and 21 nonendometriotic tumor patients. The levels of VSIG4 mRNA, VSIG4 protein expression in tumor tissue and serum soluble VSIG4 concentration were compared between the two groups. After dividing the cohort using the optimized cut-off values obtained by receiver operating characteristic curve analysis, we examined the association between VSIG4 levels and serum CA-125 levels, VSIG4 levels and the factors indicating endometriosis severity.

RESULTS

The expressions of VSIG4 mRNA, VSIG4 protein and serum VSIG4 concentration were significantly increased in the endometriotic cyst group compared with the control group (P = 0.001, 0.002 and 0.049, respectively). The optimized VSIG4 cut-off values for endometriosis prediction were 0.71, 0.32 and 144.37 pg/mL, respectively. After cohort division using these values, high VSIG4 levels group showed significantly elevated CA-125 compared with low VSIG4 level group (P = 0.010, 0.043 and 0.039, respectively). There was no association between VSIG4 levels and the factors indicating endometriosis severity.

CONCLUSION

The expression of VSIG4 in endometriosis patients is increased compared with nonendometriotic tumor patients, and higher VSIG4 levels are significantly associated with higher serum CA-125 levels. VSIG4 may be importantly involved in the immunological alteration of endometriosis.

Pharmacological targets of metabolism in disease: Opportunities from macrophages

From advances in the knowledge of the immune system, it is emerging that the specialized functions displayed by macrophages during the course of an immune response are supported by specific and dynamically-connected metabolic programs. The study of immunometabolism is demonstrating that metabolic adaptations play a critical role in modulating inflammation and, conversely, inflammation deeply influences the acquisition of specific metabolic settings.This strict connection has been proven to be crucial for the execution of defined immune functional programs and it is now under investigation with respect to several human disorders, such as diabetes, sepsis, cancer, and autoimmunity. The abnormal remodelling of the metabolic pathways in macrophages is now emerging as both marker of disease and potential target of therapeutic intervention. By focusing on key pathological conditions, namely obesity and diabetes, rheumatoid arthritis, atherosclerosis and cancer, we will review the metabolic targets suitable for therapeutic intervention in macrophages. In addition, we will discuss the major obstacles and challenges related to the development of therapeutic strategies for a pharmacological targeting of macrophage's metabolism.

Utilization of complement receptors in immune cell-microbe interaction

The complement system is a major humoral component of immunity and is essential for the fast elimination of pathogens invading the body. In addition to its indispensable role in innate immunity, the complement system is also involved in pathogen clearance during the effector phase of adaptive immunity. The fastest way of killing the invader is lysis by the membrane attack complex, which is formed by the terminal components of the complement cascade. Not all pathogens are lysed however and, if opsonized by a variety of molecules, they undergo phagocytosis and disposal inside immune cells. The most important complement-derived opsonins are C1q, the first component of the classical pathway, MBL, the initiator of the lectin pathway and C3-derived activation fragments, including C3b, iC3b and C3d, which all serve as ligands for their corresponding receptors. In this review, we discuss how complement receptors are utilized by various immune cells to tackle invading microbes, or by pathogens to evade host response.

Serum soluble VSIG4 as a surrogate marker for the diagnosis of lymphoma-associated hemophagocytic lymphohistiocytosis

Lymphoma-associated haemophagocytic lymphohistiocytosis (L-HLH) is characterized by excessively activated macrophages and cytotoxic T lymphocytes, but few reliable markers for activated macrophages are available clinically. This study, designed to discover novel biomarkers for the diagnosis of lymphoma patients with L-HLH, was initiated between 2016 and 2018. Fifty-seven adult lymphoma patients were enrolled - 39 without HLH and 18 with HLH. The differential serum protein expression profile was first screened between lymphoma patients with and without L-HLH by a quantitative mass spectrometric approach. Soluble V-set and immunoglobulin domain-containing 4 (sVSIG4), specifically expressed by macrophages, was significantly upregulated in the L-HLH group. Subsequently, sVSIG4 concentration was confirmed by enzyme-linked immunosorbent assay to be significantly increased in lymphoma patients with L-HLH. When it was exploited for the diagnosis of lymphoma patients with L-HLH, the area under a receiver operating characteristic curve was 0·98 with an optimal cut-off point of 2195 pg/ml and the corresponding sensitivity and specificity were 94·44% and 94·87% respectively. In addition, the one-year overall survival was significantly worse in patients with a sVSIG4 concentration above 2195 pg/ml compared with those below 2195 pg/ml (5·3% vs. 72·2%, P < 0·0001). sVSIG4 may be a surrogate marker of activated macrophages for the diagnosis of lymphoma patients with L-HLH.

Human Dendritic Cells Express the Complement Receptor Immunoglobulin Which Regulates T Cell Responses

The B7 family-related protein V-set and Ig containing 4 (VSIG4), also known as Z39Ig and Complement Immunoglobulin Receptor (CRIg), is the most recent of the complement receptors to be identified, with substantially distinct properties from the classical complement receptors. The receptor displays both phagocytosis-promoting and anti-inflammatory properties. The receptor has been reported to be exclusively expressed in macrophages. We now present evidence, that CRIg is also expressed in human monocyte-derived dendritic cells (MDDC), including on the cell surface, implicating its role in adaptive immunity. Three CRIg transcripts were detected and by Western blotting analysis both the known Long (L) and Short (S) forms were prominent but we also identified another form running between these two. Cytokines regulated the expression of CRIg on dendritic cells, leading to its up- or down regulation. Furthermore, the steroid dexamethasone markedly upregulated CRIg expression, and in co-culture experiments, the dexamethasone conditioned dendritic cells caused significant inhibition of the phytohemagglutinin-induced and alloantigen-induced T cell proliferation responses. In the alloantigen-induced response the production of IFNγ, TNF-α, IL-13, IL-4, and TGF-β1, were also significantly reduced in cultures with dexamethasone-treated DCs. Under these conditions dexamethasone conditioned DCs did not increase the percentage of regulatory T cells (Treg). Interestingly, this suppression could be overcome by the addition of an anti-CRIg monoclonal antibody to the cultures. Thus, CRIg expression may be a control point in dendritic cell function through which drugs and inflammatory mediators may exert their tolerogenic- or immunogenic-promoting effects on dendritic cells.

Deciphering Immune-Associated Genes to Predict Survival in Clear Cell Renal Cell Cancer

Background

To elucidate the correlations between tumor microenvironment and clinical characteristics as well as prognosis in clear cell renal cell cancer (ccRCC) and investigate the immune-associated genes by a comprehensive analysis of The Cancer Genome Atlas (TCGA) database.

Methods

We collected mRNA expression profiles of 537 ccRCC samples from the TCGA database. Immune scores and stromal scores were calculated by applying the ESTIMATE algorithm. We evaluated the correlation between immune/stromal scores and clinical characteristics as well as prognosis. The differentially expressed genes (DEGs) were screened between high immune/stromal score and low immune/stromal score groups by the cutoff of |log (fold change)| > 1, P value <0.05 by using package "limma" in R. Functional enrichment analysis was performed by DAVID, and the protein-protein interaction network of intersected DEGs between stromal score and immune score groups was conducted using the STRING database. The Kaplan-Meier method was used to explore DEGs with predictive values in overall survival, and the prognostic DEGs were further validated in a Gene Expression Omnibus (GEO) dataset GSE29609.

Results

A higher immune score was associated with T3/4 (vs. T1/2, P < 0.001), N1 (vs. N0, P=0.05), M1 (vs. M0, P=0.004), G3/4 (vs. G1/2, P < 0.001), advanced AJCC stage (P < 0.001), and shorter overall survival (P=0.04). Intersected DEGs between immune and stromal score groups were 48 upregulated and 47 downregulated genes, with 43 DEGs associated with overall survival in ccRCC. After validation by a cohort of 39 ccRCC cases with detailed follow-up information from GSE29609, six immune-associated DEGs including CASP5, HSD11B1, VSIG4, HMGCS2, HSD11B2, and OGDHL were demonstrated to be predictive of prognosis in ccRCC.

Conclusions

Our study elucidated tight associations between immune score and clinical characteristics as well as prognosis in ccRCC. Moreover, six DEGs were explored and validated to exert predictive values in overall survival of ccRCC.

Immunity, Hypoxia, and Metabolism-the Ménage à Trois of Cancer: Implications for Immunotherapy

It is generally accepted that metabolism is able to shape the immune response. Only recently we are gaining awareness that the metabolic crosstalk between different tumor compartments strongly contributes to the harsh tumor microenvironment (TME) and ultimately impairs immune cell fitness and effector functions. The major aims of this review are to provide an overview on the immune system in cancer; to position oxygen shortage and metabolic competition as the ground of a restrictive TME and as important players in the anti-tumor immune response; to define how immunotherapies affect hypoxia/oxygen delivery and the metabolic landscape of the tumor; and vice versa, how oxygen and metabolites within the TME impinge on the success of immunotherapies. By analyzing preclinical and clinical endeavors, we will discuss how a metabolic characterization of the TME can identify novel targets and signatures that could be exploited in combination with standard immunotherapies and can help to predict the benefit of new and traditional immunotherapeutic drugs.

Uncovering Potential Therapeutic Targets in Colorectal Cancer by Deciphering Mutational Status and Expression of Druggable Oncogenes

Background: Numerous driver mutations have been identified in colorectal cancer (CRC), but their relevance to the development of targeted therapies remains elusive. The secondary effects of pathogenic driver mutations on downstream signaling pathways offer a potential approach for the identification of therapeutic targets. We aimed to identify differentially expressed genes as potential drug targets linked to driver mutations. Methods: Somatic mutations and the gene expression data of 582 CRC patients were utilized, incorporating the mutational status of 39,916 and the expression levels of 20,500 genes. To uncover candidate targets, the expression levels of various genes in wild-type and mutant cases for the most frequent disruptive mutations were compared with a Mann–Whitney test. A survival analysis was performed in 2100 patients with transcriptomic gene expression data. Up-regulated genes associated with worse survival were filtered for potentially actionable targets. The most significant hits were validated in an independent set of 171 CRC patients. Results: Altogether, 426 disruptive mutation-associated upregulated genes were identified. Among these, 95 were linked to worse recurrence-free survival (RFS). Based on the druggability filter, 37 potentially actionable targets were revealed. We selected seven genes and validated their expression in 171 patient specimens. The best independently validated combinations were DUSP4 (p = 2.6 × 10⁻¹²) in ACVR2A mutated (7.7%) patients; BMP4 (p = 1.6 × 10⁻⁰⁴) in SOX9 mutated (8.1%) patients; TRIB2 (p = 1.35 × 10⁻¹⁴) in ACVR2A mutated patients; VSIG4 (p = 2.6 × 10⁻⁰⁵) in ANK3 mutated (7.6%) patients, and DUSP4 (p = 7.1 × 10⁻⁰⁴) in AMER1 mutated (8.2%) patients. Conclusions: The results uncovered potentially druggable genes in colorectal cancer. The identified mutations could enable future patient stratification for targeted therapy.

NIRF-Molecular Imaging with Synovial Macrophages-Targeting Vsig4 Nanobody for Disease Monitoring in a Mouse Model of Arthritis

Nanobody against V-set and Ig domain-containing 4 (Vsig4) on tissue macrophages, such as synovial macrophages, could visualize joint inflammation in multiple experimental arthritis models via single-photon emission computed tomography imaging. Here, we further addressed the specificity and assessed the potential for arthritis monitoring using near-infrared fluorescence (NIRF) Cy7-labeled Vsig4 nanobody (Cy7-Nb119). In vivo NIRF-imaging of collagen-induced arthritis (CIA) was performed using Cy7-Nb119. Signals obtained with Cy7-Nb119 or isotope control Cy7-NbBCII10 were compared in joints of naive mice versus CIA mice. In addition, pathological microscopy and fluorescence microscopy were used to validate the arthritis development in CIA. Cy7-Nb119 accumulated in inflamed joints of CIA mice, but not the naive mice. Development of symptoms in CIA was reflected in increased joint accumulation of Cy7-Nb119, which correlated with the conventional measurements of disease. Vsig4 is co-expressed with F4/80, indicating targeting of the increasing number of synovial macrophages associated with the severity of inflammation by the Vsig4 nanobody. NIRF imaging with Cy7-Nb119 allows specific assessment of inflammation in experimental arthritis and provides complementary information to clinical scoring for quantitative, non-invasive and economical monitoring of the pathological process. Nanobody labelled with fluorescence can also be used for ex vivo validation experiments using flow cytometry and fluorescence microscopy.

Expression of Vsig4 attenuates macrophage-mediated hepatic inflammation and fibrosis in high fat diet (HFD)-induced mice

The innate immune response contributes to hepatic steatosis and nonalcoholic fatty liver disease (NAFLD). However, the pathogenic mechanism of NAFLD is still poorly understood. The costimulatory molecule V-set and immunoglobulin domain-containing protein-4 (Vsig4), which is exclusively expressed on macrophages, shows significant role in regulating macrophage-mediated inflammation. Here, we attempted to explore if Vsig4 expression was involved in high fat diet (HFD)-induced NAFLD. The results indicated that Vsig4 expression was markedly down-regulated in fatty livers of NAFLD patients and obese mice. Vsig4 knockout accelerated HFD-induced metabolic dysfunction. In addition, the loss of Vsig4 significantly promoted insulin resistance and lipid deposition in liver samples of HFD-challenged mice. Furthermore, HFD-induced inflammation was apparently accelerated in Vsig4 knockout mice by further activating nuclear factor-κB (NF-κB) signaling pathway. Also, Vsig4 deficient mice exhibited greater collagen accumulation in hepatic samples in HFD-challenged mice compared to the WT mice, which was through promoting transforming growth factor-β1 (TGFβ1) signaling. Importantly, we found that lipopolysaccharide (LPS)- or TGFβ1-stimulated inflammation and fibrosis in primary hepatocytes and hepatic stellate cells, respectively, were markedly exacerbated by co-culture with condition medium from bone marrow-derived macrophages (BMDMs) with Vsig4 deficiency. Finally, transplantation of bone marrow cells from control mice to Vsig4-knockout mice restored the severity of steatosis, inflammation and fibrosis after HFD feeding. Therefore, loss of Vsig4 accelerated the severity of lipid deposition, fibrosis and the inflammatory response. Vsig4 could be a therapeutic target for NAFLD treatment.

CD49a Expression Identifies a Subset of Intrahepatic Macrophages in Humans

Macrophages play central roles in inflammatory reactions and initiation of immune responses during infections. More than 80% of total tissue macrophages are described to be located in the liver as liver-resident macrophages, also named Kupffer cells (KCs). While studies in mice have established a central role of liver-resident KCs in regulating liver inflammation, their phenotype and function are not well-characterized in humans. Comparing paired human liver and peripheral blood samples, we observed significant differences in the distribution of macrophage (Mφ) subsets, with lower frequencies of CD14^hiCD16^lo and higher frequencies of CD14^int−hiCD16^int Mφ in human livers. Intrahepatic Mφ consisted of diverse subsets with differential expression of CD49a, a liver-residency marker previously described for human and mice NK cells, and VSIG4 and/or MARCO, two recently described human tissue Mφ markers. Furthermore, intrahepatic CD49a⁺ Mφ expressed significantly higher levels of maturation and activation markers, exhibited higher baseline levels of TNF-α, IL-12, and IL-10 production, but responded less to additional in vitro TLR stimulation. In contrast, intrahepatic CD49a⁻ Mφ were highly responsive to stimulation with TLR ligands, similar to what was observed for CD49a⁻ monocytes (MOs) in peripheral blood. Taken together, these studies identified populations of CD49a⁺, VSIG4⁺, and/or MARCO⁺ Mφ in human livers, and demonstrated that intrahepatic CD49a⁺ Mφ differed in phenotype and function from intrahepatic CD49a⁻ Mφ as well as from peripheral blood-derived monocytes.

Endostar regulates EMT, migration and invasion of lung cancer cells through the HGF-Met pathway

AIM

Though Endostar (ES) could inhibit tumor growth by inhibiting tumor angiogenesis, other possible mechanisms have been less reported. This study aims to investigate the role of ES in the treatment of lung cancer from the perspective of macrophage-mediated epithelial mesenchymal transformation (EMT).

METHODS

THP1 cells were induced to polarized macrophages (MΦ). A549 and H1795 cells were separately treated with MΦ conditioned medium, ES (12.5 μg/ml) and HGF (5 ng/ml) for 24 h at 37 °C. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect the expression levels of CCL17, CD163, hepatocyte growth factor (HGF), Epidermal Growth Factor (EGF), transforming growth factor (TGF)-β1 and interleukin (IL)-6. Western blot was carried out to detect the p-MET, MET and EMT-related proteins (E-cadherin, N-cadherin, Snail and vimentin). Fibroblast-like A549 and H1975 cells were observed by a microscope. Cell invasion and migration were observed and analyzed by transwell and scratch assays.

RESULTS

The expression levels of CCL17 and CD163 were significant higher in MΦ. ES significantly inhibited the expression of HGF in MΦ. Moreover, ES could restore the abnormal expressions of EMT-related proteins and inhibit MΦ-induced and HGF-induced fibroblast-like lung cancer cells. Furthermore, ES suppressed the MΦ-induced and HGF-induced migration and invasion of lung cancer cells. ES was also found to down-regulate HGF-Met signaling in HGF-treated lung cancer cells.

CONCLUSION

ES suppresses lung cancer progression by down-regulating HGF-Met signaling, revealing the possible mechanism of ES in the process of treating lung cancer patients.