Optimum immunohistochemical procedures for analysis of macrophages in human and mouse formalin fixed paraffin-embedded tissue samples

Recent Advancements in Subcellular Proteomics: Growing Impact of Organellar Protein Niches on the Understanding of Cell Biology

The mammalian cell is a complex entity, with membrane-bound and membrane-less organelles playing vital roles in regulating cellular homeostasis. Organellar protein niches drive discrete biological processes and cell functions, thus maintaining cell equilibrium. Cellular processes such as signaling, growth, proliferation, motility, and programmed cell death require dynamic protein movements between cell compartments. Aberrant protein localization is associated with a wide range of diseases. Therefore, analyzing the subcellular proteome of the cell can provide a comprehensive overview of cellular biology. With recent advancements in mass spectrometry, imaging technology, computational tools, and deep machine learning algorithms, studies pertaining to subcellular protein localization and their dynamic distributions are gaining momentum. These studies reveal changing interaction networks because of "moonlighting proteins" and serve as a discovery tool for disease network mechanisms. Consequently, this review aims to provide a comprehensive repository for recent advancements in subcellular proteomics subcontexting methods, challenges, and future perspectives for method developers. In summary, subcellular proteomics is crucial to the understanding of the fundamental cellular mechanisms and the associated diseases.

Age-associated reduction of sinus macrophages in human mesenteric lymph nodes

There are numerous macrophages and dendritic cells in lymph nodes (LNs). Recent studies have highlighted that sinus macrophages (SMs) in LNs possess antigen-presenting capabilities and are related to anti-cancer immune responses. In this study, we assessed the distribution of SMs in mesenteric LNs removed during surgery for colorectal cancer. A marked reduction of SMs was noted in elderly patients, particularly those over 80 years old. We observed a disappearance of CD169-positive cells in LNs where SMs were reduced. In silico analysis of publicly available single-cell RNA sequencing data from LNs revealed that CD169-positive macrophages express numerous genes associated with antigen presentation and lymphocyte proliferation, similar to dendritic cells' functions. In conclusion, our study demonstrates that SMs, potentially crucial for immune activation, diminish in the LNs of elderly patients. This reduction of SMs may contribute to the immune dysfunction observed in the elderly.

Impacts of cytoplasmic p53 aggregates on the prognosis and the transcriptome in lung squamous cell carcinoma

The tumor suppressor TP53 gene, the most frequently mutated gene in human cancers, produces the product tumor protein p53, which plays an essential role in DNA damage. p53 protein mutations may contribute to tumorigenesis by loss of tumor suppressive functions and malignancy of cancer cells via gain-of-oncogenic functions. We previously reported that mutant p53 proteins form aggregates and that cytoplasmic p53 aggregates were associated with poor prognosis in human ovarian cancer. However, the prognostic impact of p53 aggregation in other tumors including lung squamous cell carcinoma (SCC) is poorly understood. Here, we demonstrated that lung SCC cases with cytoplasmic p53 aggregates had a significantly poor clinical prognosis. Analysis via patient-derived tumor organoids (PDOs) established from lung SCC patients and possessing cytoplasmic p53 aggregates showed that eliminating cytoplasmic p53 aggregates suppressed cell proliferation. RNA sequencing and transcriptome analysis of p53 aggregate-harboring PDOs indicated multiple candidate pathways involved in p53 aggregate oncogenic functions. With lung SCC-derived cell lines, we found that cytoplasmic p53 aggregates contributed to cisplatin resistance. This study thus shows that p53 aggregates are a predictor of poor prognosis in lung SCC and suggests that detecting p53 aggregates via p53 conventional immunohistochemical analysis may aid patient selection for platinum-based therapy.

IL-32 production from lung adenocarcinoma cells is potentially involved in immunosuppressive microenvironment

Interleukin 32 (IL-32) is a proinflammatory cytokine secreted from several kinds of cancer cells. In the present study, we investigated the significance of IL-32 in lung adenocarcinoma by immunohistochemistry and bioinformatics analysis. IL-32 was positive in cancer cells of 21 cases (9.2%) of total 228 cases. Increased IL-32 gene expression was linked to worse clinical course in TCGA analysis, however, IL-32 expression in immunohistochemistry was not associated to clinical course in our cohort. It was also found that high IL-32 expression was seen in cases with increased lymphocyte infiltration. In vitro studies indicated that IFN-γ induced gene expression of IL-32 and PD1-ligands in lung adenocarcinoma cell lines. IL-32, especially IL-32β, also induced overexpression of PD1-ligands in human monocyte-derived macrophages. Additionally, Cancer-cell-derived IL-32 was elevated by stimulation with anticancer agents. In conclusion, IL-32 potentially induced by inflammatory conditions and anticancer therapy and contribute to immune escape of cancer cells via development the immunosuppressive microenvironment. IL-32 might be a target molecule for anti-cancer therapy.

Systematic development of immunohistochemistry protocol for large cryosections-specific to non-perfused fetal brain

BACKGROUND

Immunohistochemistry (IHC) is an important technique in understanding the expression of neurochemical molecules in the developing human brain. Despite its routine application in the research and clinical setup, the IHC protocol specific for soft fragile fetal brains that are fixed using the non-perfusion method is still limited in studying the whole brain.

NEW METHOD

This study shows that the IHC protocols, using a chromogenic detection system, used in animals and adult humans are not optimal in the fetal brains. We have optimized key steps from Antigen retrieval (AR) to chromogen visualization for formalin-fixed whole-brain cryosections (20 µm) mounted on glass slides.

RESULTS

We show the results from six validated, commonly used antibodies to study the fetal brain. We achieved optimal antigen retrieval with 0.1 M Boric Acid, pH 9.0 at 70°C for 20 minutes. We also present the optimal incubation duration and temperature for protein blocking and the primary antibody that results in specific antigen labeling with minimal tissue damage.

COMPARISON WITH EXISTING METHODS

The IHC protocol commonly used for adult human and animal brains results in significant tissue damage in the fetal brains with little or suboptimal antigen expression. Our new method with important modifications including the temperature, duration, and choice of the alkaline buffer for AR addresses these pitfalls and provides high-quality results.

CONCLUSION

The optimized IHC protocol for the developing human brain (13-22 GW) provides a high-quality, repeatable, and reliable method for studying chemoarchitecture in neurotypical and pathological conditions across different gestational ages.

Hypoxia-related carbonic anhydrase 9 induces serpinB9 expression in cancer cells and apoptosis in T cells via acidosis

Hypoxia is a common feature of solid tumors. However, the impact of hypoxia on immune cells within tumor environments remains underexplored. Carbonic anhydrase 9 (CA9) is a hypoxia-responsive tumor-associated enzyme. We previously noted that regardless of human CA9 (hCA9) expression, hCA9-expressing mouse renal cell carcinoma RENCA (RENCA/hCA9) presented as a "cold" tumor in syngeneic aged mice. This study delves into the mechanisms behind this observation. Gene microarray analyses showed that RENCA/hCA9 cells exhibited elevated mouse serpinB9, an inhibitor of granzyme B, relative to RENCA cells. Corroborating this, RENCA/hCA9 cells displayed heightened resistance to antigen-specific cytotoxic T cells compared with RENCA cells. Notably, siRNA-mediated serpinB9 knockdown reclaimed this sensitivity. In vivo tests showed that serpinB9 inhibitor administration slowed RENCA tumor growth, but this effect was reduced in RENCA/hCA9 tumors, even with adjunctive immune checkpoint blockade therapy. Further, inducing hypoxia or introducing the mouse CA9 gene upregulated serpinB9 expression, and siRNA-mediated knockdown of the mouse CA9 gene inhibited the hypoxia-induced induction of serpinB9 in the original RENCA cells. Supernatants from RENCA/hCA9 cultures had lower pH than those from RENCA, suggesting acidosis. This acidity enhanced serpinB9 expression and T cell apoptosis. Moreover, coculturing with RENCA/hCA9 cells more actively prompted T cell apoptosis than with RENCA cells. Collectively, these findings suggest hypoxia-associated CA9 not only boosts serpinB9 in cancer cells but also synergistically intensifies T cell apoptosis via acidosis, characterizing RENCA/hCA9 tumors as "cold."

Pivotal role of IL-8 derived from the interaction between osteosarcoma and tumor-associated macrophages in osteosarcoma growth and metastasis via the FAK pathway

The prognosis of osteosarcoma (OS) has remained stagnant over the past two decades, requiring the exploration of new therapeutic targets. Cytokines, arising from tumor-associated macrophages (TAMs), a major component of the tumor microenvironment (TME), have garnered attention owing to their impact on tumor growth, invasion, metastasis, and resistance to chemotherapy. Nonetheless, the precise functional role of TAMs in OS progression requires further investigation. In this study, we investigated the interaction between OS and TAMs, as well as the contribution of TAM-produced cytokines to OS advancement. TAMs were observed to be more prevalent in lung metastases compared with that in primary tumors, suggesting their potential support for OS progression. To simulate the TME, OS and TAMs were co-cultured, and the cytokines resulting from this co-culture could stimulate OS proliferation, migration, and invasion. A detailed investigation of cytokines in the co-culture conditioned medium (CM) revealed a substantial increase in IL-8, establishing it as a pivotal cytokine in the process of enhancing OS proliferation, migration, and invasion through the focal adhesion kinase (FAK) pathway. In an in vivo model, co-culture CM promoted OS proliferation and lung metastasis, effects that were mitigated by anti-IL-8 antibodies. Collectively, IL-8, generated within the TME formed by OS and TAMs, accelerates OS proliferation and metastasis via the FAK pathway, thereby positioning IL-8 as a potential novel therapeutic target in OS.

Anticancer immune reaction and lymph node sinus macrophages: a review from human and animal studies

Lymph nodes are secondary lymphoid organs localized throughout the body that typically appear as bean-like nodules. Numerous antigen-presenting cells, including dendritic cells and macrophages, that mediate host defense responses against pathogens, such as bacteria and viruses, reside within lymph nodes. To react to cancer cell-derived antigens in a variety of cancers, antigen-presenting cells induce cytotoxic T lymphocytes (CTLs). In relation to anticancer immune responses, macrophages in the lymph node sinus have been of particular interest because a number of studies involving both human specimens and animal models have reported that lymph node macrophages expressing CD169 play a key role in activating anticancer CTLs. Recent studies have indicated that dysfunction of lymph node macrophages potentially contributes to immune suppression in elderly patients and immunological "cold" tumors. Therefore, in anticancer therapy, the regulation of lymph node macrophages is a potentially promising approach.

Age-related neuroimmune signatures in dorsal root ganglia of a Fabry disease mouse model

Pain in Fabry disease (FD) is generally accepted to result from neuronal damage in the peripheral nervous system as a consequence of excess lipid storage caused by alpha-galactosidase A (α-Gal A) deficiency. Signatures of pain arising from nerve injuries are generally associated with changes of number, location and phenotypes of immune cells within dorsal root ganglia (DRG). However, the neuroimmune processes in the DRG linked to accumulating glycosphingolipids in Fabry disease are insufficiently understood.Therefore, using indirect immune fluorescence microscopy, transmigration assays and FACS together with transcriptomic signatures associated with immune processes, we assessed age-dependent neuroimmune alterations in DRG obtained from mice with a global depletion of α-Gal A as a valid mouse model for FD. Macrophage numbers in the DRG of FD mice were unaltered, and BV-2 cells as a model for monocytic cells did not show augmented migratory reactions to glycosphingolipids exposure suggesting that these do not act as chemoattractants in FD. However, we found pronounced alterations of lysosomal signatures in sensory neurons and of macrophage morphology and phenotypes in FD DRG. Macrophages exhibited reduced morphological complexity indicated by a smaller number of ramifications and more rounded shape, which were age dependent and indicative of premature monocytic aging together with upregulated expression of markers CD68 and CD163.In our FD mouse model, the observed phenotypic changes in myeloid cell populations of the DRG suggest enhanced phagocytic and unaltered proliferative capacity of macrophages as compared to wildtype control mice. We suggest that macrophages may participate in FD pathogenesis and targeting macrophages at an early stage of FD may offer new treatment options other than enzyme replacement therapy.

Ideal Duration of Pretreatment Using a Gelatin Hydrogel Nonwoven Fabric Prior to Subcutaneous Islet Transplantation

Subcutaneous islet transplantation is a promising treatment for severe diabetes; however, poor engraftment hinders its prevalence. We previously revealed that a gelatin hydrogel nonwoven fabric (GHNF) markedly improved subcutaneous islet engraftment in comparison with intraportal islet transplantation. We herein investigated whether the duration of pretreatment using GHNF affected the outcome of subcutaneous islet transplantation. A silicone spacer with GHNF was implanted into the subcutaneous space of healthy mice at 2, 4, 6, or 8 weeks before transplantation, and then diabetes was induced 7 days before transplantation. Syngeneic islets were transplanted into the pretreated space. Blood glucose, intraperitoneal glucose tolerance, immunohistochemistry, inflammatory mediators, and gene expression were evaluated. The 6-week group showed significantly better blood glucose changes than the other groups (P < 0.05). The cure rate of the 6-week group (60.0%) was the highest among the groups (2-week = 0%, 4-week = 50.0%, 8-week = 15.4%). The number of von Willebrand factor (vWF)-positive vessels in the 6-week group was significantly higher than in the other groups at pre-islet and post-islet transplantation (P < 0.01 [vs 2-and 4-week groups] and P < 0.05 [vs all other groups], respectively). Notably, this beneficial effect was also observed when GHNF was implanted into diabetic mice injected with streptozotocin 7 days before GHNF implantation. The positive rates for laminin, collagen III, and collagen IV increased as the duration of pretreatment became longer and were significantly higher in the 8-week group (P < 0.01). Inflammatory mediators, including interleukin (IL)-1b, granulocyte colony-stimulating factor (G-CSF), and interferon (IFN)-γ, were gradually downregulated according to the duration of GHNF pretreatment and re-elevated in the 8-week group. Taken together, the duration of GHNF pretreatment apparently had an impact on the outcomes of subcutaneous islet transplantation, and 6 weeks appeared to be the ideal duration. Islet graft revascularization, extracellular matrix compensation of the islet capsule, and the inflammatory status at the subcutaneous space would be crucial factors for successful subcutaneous islet transplantation.

Resistance to chemical carcinogenesis induction via a dampened inflammatory response in naked mole-rats

Naked mole-rats (NMRs) have a very low spontaneous carcinogenesis rate, which has prompted studies on the responsible mechanisms to provide clues for human cancer prevention. However, it remains unknown whether and how NMR tissues respond to experimental carcinogenesis induction. Here, we show that NMRs exhibit extraordinary resistance against potent chemical carcinogenesis induction through a dampened inflammatory response. Although carcinogenic insults damaged skin cells of both NMRs and mice, NMR skin showed markedly lower immune cell infiltration. NMRs harbour loss-of-function mutations in RIPK3 and MLKL genes, which are essential for necroptosis, a type of necrotic cell death that activates strong inflammation. In mice, disruption of Ripk3 reduced immune cell infiltration and delayed carcinogenesis. Therefore, necroptosis deficiency may serve as a cancer resistance mechanism via attenuating the inflammatory response in NMRs. Our study sheds light on the importance of a dampened inflammatory response as a non-cell-autonomous cancer resistance mechanism in NMRs.

Naked mole rats are found to be resistant to cancer development through dampened inflammatory response due to genetically determined impaired necroptosis, with essential necroptosis genes RIPK3 and MLKL containing mutations causing premature stop codons.

Heparin Immobilization of Tissue Engineered Xenogeneic Small Diameter Arterial Scaffold Improve Endothelialization

BACKGROUND

Autologous vessels graft (Inner diameter < 6 mm) harvesting always challenged during bypass grafting surgery and its complication shows poor outcome. Tissue engineered vascular graft allow to generate biological graft without any immunogenic complication. The approach presented in this study is to induce graft remodeling through heparin coating in luminal surface of small diameter (Inner diameter < 1 mm) decellularized arterial graft.

METHODS

Decellularization of graft was done using SDS, combination of 0.5% sodium dodecyl sulfate and 0.5% sodium deoxycholate and only sodium deoxycholate. Decellularization was confirmed on basis of histology, and DAPI. Characterization of extracellular matrix was analyzed using histology and scanning electron microscopy. Surface modification of decellularized vascular graft was done with heparin coating. Heparin immobilization was evaluated by toluidine blue stain. Heparin-coated graft was transplanted end to end anastomosis in femoral artery in rat.

RESULTS

Combination of 0.5% sodium dodecyl sulfate and 0.5% Sodium deoxycholate showed complete removal of xenogeneic cells. The heparin coating on luminal surface showed anti-thrombogenicity and endothelialization. Mechanical testing revealed no significant differences in strain characteristics and modulus between native tissues, decellularized scaffolds and transplanted scaffold. Collectively, this study proposed a heparin-immobilized ECM coating to surface modification offering functionalize biomaterials for developing small-diameter vascular grafts.

CONCLUSION

We conclude that xenogeneic decellularized arterial scaffold with heparin surface modification can be fabricated and successfully transplanted small diameter (inner diameter < 1 mm) decellularized arterial graft.

Cell composition at the vitreomacular interface in traumatic macular holes

Purpose

To describe characteristics of the vitreomacular interface (VMI) in traumatic macular holes (TMH) compared to idiopathic macular holes (IMH) using immunofluorescence and electron microscopy, and to correlate with clinical data.

Methods

For immunocytochemical and ultrastructural analyses, premacular tissue with internal limiting membrane (ILM) and epiretinal membrane (ERM) was harvested during vitrectomy from 5 eyes with TMH and 5 eyes with IMH. All specimens were processed as flat mounts for phase-contrast microscopy, interference and fluorescence microscopy, and transmission electron microscopy (TEM). Primary antibodies were used against microglial and macroglial cells. Clinical data was retrospectively evaluated.

Results

Surgically excised premacular tissue of eyes with TMH showed a less pronounced positive immunoreactivity for anti-glutamine synthetase, anti-vimentin and anti-IBA1 compared to eyes with IMH. Cell nuclei staining of the flat-mounted specimens as well as TEM presented a lower cell count in eyes with TMH compared to IMH. All detected cells were found on the vitreal side of the ILM. No collagen fibrils were seen in specimens of TMH. According to patients’ age, intraoperative data as well as spectral-domain optical coherence tomography (SD-OCT) analysis revealed an attached posterior vitreous in the majority of TMH cases (60%), whereas all eyes with IMH presented posterior vitreous detachment.

Conclusion

The vitreomacular interface in TMH and IMH shows significant differences. In TMH, glial cells are a rare finding on the vitreal side of the ILM.

Efficacy of the Antigenicity-Retaining Ability of Fixative Solutions for Liquid-Based Cytology: Immunocytochemistry of Long-Term Storage

INTRODUCTION/OBJECTIVE

Liquid-based cytology (LBC) is advantageous as multiple stained specimens can be prepared and used for additional assays such as immunocytochemical and molecular-pathological investigations. Two types of preservative-fixative solutions (fixatives) are used for nongynecologic specimens used in the BD SurePath-LBC (SP-LBC) method, and their components vary. However, few studies have evaluated the differences in antigen-retaining ability between these fixatives. Therefore, we investigated and compared the antigen-retaining ability of the fixatives in immunocytochemical staining (ICC) under long-term storage conditions.

MATERIALS AND METHODS

Sediments of cultured RAJI cells (derived from Burkitt's lymphoma) were added to each fixative (red and blue) and stored at room temperature for a specified period (1 h; 1 week; and 1, 3, and 6 months). The specimens were then prepared using the SP-LBC method and subjected to ICC. Positivity rate was calculated using the specimens fixed at room temperature for 1 h as a control. Antibodies against Ki67 expressed in the nucleus and against CD20 and leukocyte common antigen (LCA) expressed on the cell membrane were used.

RESULTS

For CD20 and LCA, the positivity rate increased with time in the red fixative compared with that in the control. In the blue fixative, the positivity rate was highest at 1 h and was maintained at a high level throughout the storage period. In contrast, the Ki67 positivity rate was highest at 1 h in both red and blue fixatives and markedly decreased with time. Therefore, although refrigerated (8°C) storage was used, no improvement was noted.

CONCLUSIONS

Long-term storage is possible for cell membrane antigens at room temperature; however, it is unsuitable for intranuclear antigens. Therefore, we conclude that suitable fixative type and storage temperature differ based on antigen location. Further investigation is warranted.

The ratio of CD163-positive macrophages to Iba1-positive macrophages is low in the intima in the early stage of cutaneous arteritis

The etiology of polyarteritis nodosa (PAN) and localized PAN, including cutaneous arteritis (CA), remains unknown; however, initial endothelial damage has been implicated. The intima of the vasculitis lesions is predominantly infiltrated by innate-like bystander-activated CD8 T cells, in addition to the macrophages. Macrophages are among the major inflammatory cells involved in innate immunity and are classified into M1 and M2 subtypes. M1-type macrophages kill pathogens and cause inflammation, while M2-type macrophages promote the repair of tissues. Macrophage subtypes infiltrating in PAN and localized PAN vasculitis lesions have not yet been investigated. Innate immune response to a triggering factor on the endothelial cell surface may initiate CA pathogenesis. Thus, many M1-type macrophages may infiltrate in the intima during early CA. We assessed this hypothesis by immunohistochemical observation of macrophage phenotypes and polarization. Twenty-seven skin biopsy specimens from patients with CA were retrieved. Based on histology, we classified CA into four phases. The phenotypes of infiltrating macrophages in CA were evaluated by immunohistochemistry using antibodies against Iba-1, a pan-macrophage marker, and CD163, an M2-type macrophage marker. Our results showed that the ratio of CD163-positive M2-type macrophages to Iba1-positive macrophages was lower in the intima in the early stage of CA than in the later stage. In the media to adventitia, there was no significant difference in the ratios between these stages. These findings indicate that innate immunity is involved in the intima in the early stage of CA, suggesting that a trigger for CA might exist in endothelial cells.

Anti-Cancer Immune Reaction and Lymph Node Macrophage; A Review from Human and Animal Studies

Lymph nodes are secondary lymphoid organs that appear as bean-like nodules usually <1 cm in size, and they are localized throughout the body. Many antigen-presenting cells such as dendritic cells and macrophages reside in lymph nodes, where they mediate host defense responses against pathogens such as viruses and bacteria. In cancers, antigen-presenting cells induce cytotoxic T lymphocytes (CTLs) to react to cancer cell-derived antigens. Macrophages located in the lymph node sinus are of particular interest in relation to anti-cancer immune responses because many studies using both human specimens and animal models have suggested that lymph node macrophages expressing CD169 play a key role in activating anti-cancer CTLs. The regulation of lymph node macrophages therefore represents a potentially promising novel approach in anti-cancer therapy.

T-cell responses and combined immunotherapy against human carbonic anhydrase 9-expressing mouse renal cell carcinoma

Renal cell carcinoma (RCC) is known to respond to immune checkpoint blockade (ICB) therapy, whereas there has been limited analysis of T-cell responses to RCC. In this study, we utilized human carbonic anhydrase 9 (hCA9) as a model neoantigen of mouse RENCA RCC. hCA9-expressing RENCA RCC (RENCA/hCA9) cells were rejected in young mice but grew in aged mice. CD8⁺ T cells were the primary effector cells involved in rejection in young mice, whereas CD4⁺ T cells participated at the early stage. Screening of a panel of hCA9-derived peptides revealed that mouse CD8⁺ T cells responded to hCA9_288-296 peptide. Mouse CD4⁺ T cells responded to lysates of RENCA/hCA9, but not RENCA cells, and showed reactivity to hCA9 _276-290, which shares three amino acids with hCA9 _288-296 peptide. Immunohistochemistry analysis revealed that few T cells infiltrated RENCA/hCA9 tissues in aged mice. ICB therapy of anti-PD-1/anti-CTLA-4 antibodies promoted T-cell infiltration into tumor tissues, whereas no definite antitumor effect was observed. However, additional combination with cyclophosphamide or axitinib, a vascular endothelial growth factor receptor inhibitor, induced complete regression in half of the RENCA/hCA9-bearing aged mice with increased expression of PD-L1 in tumor tissues. These results indicate that hCA9 can be a useful model neoantigen to investigate antitumor T-cell responses in mice with RCC, and that RENCA/hCA9 in aged mice can serve as a non-inflamed 'cold' tumor model facilitating the development of effective combined immunotherapies for RCC.

Subcellular proteomics

The eukaryotic cell is compartmentalized into subcellular niches, including membrane-bound and membrane-less organelles. Proteins localize to these niches to fulfil their function, enabling discreet biological processes to occur in synchrony. Dynamic movement of proteins between niches is essential for cellular processes such as signalling, growth, proliferation, motility and programmed cell death, and mutations causing aberrant protein localization are associated with a wide range of diseases. Determining the location of proteins in different cell states and cell types and how proteins relocalize following perturbation is important for understanding their functions, related cellular processes and pathologies associated with their mislocalization. In this Primer, we cover the major spatial proteomics methods for determining the location, distribution and abundance of proteins within subcellular structures. These technologies include fluorescent imaging, protein proximity labelling, organelle purification and cell-wide biochemical fractionation. We describe their workflows, data outputs and applications in exploring different cell biological scenarios, and discuss their main limitations. Finally, we describe emerging technologies and identify areas that require technological innovation to allow better characterization of the spatial proteome.

CD169 Expression on Lymph Node Macrophages Predicts in Patients With Gastric Cancer

The induction of an anti-cancer immune responses is potentially associated with the efficacy of anti-cancer therapy. Recent studies have indicated that sinus macrophages in regional lymph nodes are involved in anti-cancer immune responses in the cancer microenvironment. In the present study, we investigated the correlation between lymphocyte infiltration in cancer tissues and macrophage activation in regional lymph nodes. We retrospectively identified 294 patients with gastric cancer who underwent surgery from 2008 to 2012. Using immunohistochemistry, we evaluated CD169-expression on CD68-positive macrophages, and the density of CD8-postive lymphocytes in tumor microenvironment. We statistically examined the correlation between CD169 and CD8 expression, and performed Cox regression analysis of potential prognostic factors, including CD169 and CD8 expression, for cancer-specific survival (CSS) in patients with total and advanced gastric cancer. CD169 overexpression in lymph node sinus macrophages (LySMs) was positively correlated to the density of CD8-positive lymphocytes in primary cancer tissues (R = 0.367, p < 0.001). A high density of CD8-positive T lymphocytes in the primary site and a high level of CD169 expression in LySMs were independently associated with greater CSS in patients with total and advanced gastric cancer (p < 0.05 for all). The expression on CD169 in LySMs is a predictor of a favorable clinical course in patients with gastric cancer, and might be useful for evaluating anti-cancer immune responses.

Macrophage CCL22 expression promotes lymphangiogenesis in patients with tongue squamous cell carcinoma via IL-4/STAT6 in the tumor microenvironment

The C-C motif chemokine ligand 22 (CCL22) chemokine is produced by M2-like tumor-associated macrophages (TAMs) in the tumor microenvironment. Chemokine C-C motif receptor 4 (CCR4), the CCL22 receptor, on T helper2 (Th2) cells leads to a Th2 cytokine-dominant environment. In our previous study, lymph node metastasis was the main predictor of tongue squamous cell carcinoma (SCC) via CCL22. Therefore, the present study aimed to investigate the effects of CCL22 and a Th2 cytokine-predominant tumor microenvironment on vascular endothelial growth factor (VEGF)-C expression and lymphangiogenesis. The post-operative courses of 110 patients with early-stage tongue SCC with a histopathological diagnosis based on the 8th TNM classification were followed up (mean/median follow-up time, 47.1/42.0 months) from surgery until death or the last follow-up visit, and subsequent lymph node relapse was assessed. Lymphangiogenesis and the immunohistochemical expression of several markers (CCL22, CCR4 and VEGF-C) were evaluated. The Kaplan-Meier method was used to plot lymph node relapse-free survival and overall survival curves, which were compared using the log-rank test. In vitro, the association between CCL22 and VEGF-C by interleukin (IL)-4/signal transducer and activator of transcription 6 (STAT6) stimulation was examined. Lymphangiogenesis was significantly associated with lymph node relapse (P<0.001) and a CCL22⁺ macrophage ratio (P<0.001). CCL22⁺ TAMs were positive for VEGF-C and surrounded by CCR4⁺ cells. Additionally, VEGF-C expression was increased in IL-4/STAT6-stimulated macrophages. In addition, the STAT6 signaling pathway was activated in the SCC cells in the deeply invaded part of the tumor along with the aggregated macrophages. In conclusion, TAM CCL22 expression led to lymph node relapse via VEGF-C expression within the tumor microenvironment and the IL-4/STAT6 signaling pathway in early stage tongue SCC. Additionally, the worst pattern of invasion and depth of invasion were revealed to be useful parameters for lymph node relapse in patients with tongue SCC. The present study suggested that CCL22 contributed to the role of M2-like differentiated TAMs in prognosis and lymph node relapse via IL-4/STAT6 and VEGF. The IL-4/STAT6 signaling pathway may be a new molecular target for tongue SCC.

Imaging the future: the emerging era of single-cell spatial proteomics

The proteome of a human cell is partitioned within organelles, such as the nucleus, and other subcellular compartments, such as the cytoplasm, forming a myriad of membrane-bound and membrane-free ultrastructures. This compartmentalization allows discrete biochemical processes to occur efficiently in isolation, with relevant proteins localized to appropriate niches to fulfill their biological function(s). Proper delivery and dynamic exchange of proteins between compartments underlie the regulation of many cellular processes, such as cell signaling, division, and programmed cell death. To this end, cells deploy dedicated trafficking mechanisms to ensure correct protein localization, as mis-localization can result in pathology. In addition to trafficking, variation in the expression, modification, and physical associations of proteins within and between cells can result in biological heterogeneity, motivating the need for single-cell measurements. In this review, we introduce diverse platform technologies developed for subcellular proteomics and high-throughput systems biology, with the aim of providing mechanistic insights into fundamental cell biological processes underlying healthy and diseased states, and valuable public data resources. In contrast to the rapidly advancing field of single-cell genomics, the single-cell spatial proteomics toolbox remains in its infancy, but is poised to make considerable advances in the coming years.

HFD-induced hepatic lipid accumulation and inflammation are decreased in Factor D deficient mouse

Excessive intake of fat causes accumulation of fat in liver, leading to non-alcoholic fatty liver disease (NAFLD). High-fat diet (HFD) upregulates the expression of Factor D, a complement pathway component, in the liver of mice. However, the functions of Factor D in liver are not well known. Therefore, the current study investigated the relationship between Factor D and hepatic lipid accumulation using CRISPR/Cas9-mediated Factor D knockout (FD-KO) mice. Factor D deficiency downregulated expression of genes related to fatty acid uptake and de novo lipogenesis in the liver. Furthermore, Factor D deficiency reduced the expression of inflammatory factors (Tnf and Ccl2) and fibrosis markers and decreased accumulation of F4/80-positive macrophages. These data suggest that the Factor D deficiency improved hepatic lipid accumulation and hepatic inflammation in HFD-fed mice.

A case of suprasellar Erdheim-Chester disease and characterization of macrophage phenotype

Erdheim-Chester disease (ECD) is a non-Langerhans form of histiocytosis that occurs in systemic organs, such as bone, the central nervous system, cardiovascular system, lungs, and kidneys. We report the case of a 68-year-old woman with a cranial pharyngeal tumor and a bone lesion in the tibia. The case was diagnosed as ECD. Pathological analysis showed the typical feature of foamy macrophage accumulation. The macrophages were positive for CD68, and negative for CD1a and S100. The BRAF V600E mutation was identified. In addition, immunohistochemistry was performed for the detailed characterization of the macrophages. The macrophages had low proliferative activity and an M2-like phenotype, and they expressed colony-stimulating factor-1 receptor (CSF1R) on the cell surface.

Phenotypic Changes in Macrophage Activation in a Model of Nonalcoholic Fatty Liver Disease using Microminipigs

Aim: Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver disorders associated with metabolic syndrome, and its prevalence has been on the rise. The pathogenesis of NAFLD has not yet been sufficiently elucidated due to the multifactorial nature of the disease, although the activation of macrophages/Kupffer cells is considered to be involved. We previously reported an animal model of NAFLD using Microminipigs ^TM (µMPs) fed high-fat diets containing cholesterol with or without cholic acid. The aim of this study was to investigate the phenotypic changes of macrophages that occur during the development of NAFLD.

Methods: Immunohistochemistry of macrophages, lymphocytes, and stellate cells was performed using liver samples, and the density of positive cells was analyzed.

Results: The number of Iba-1-positive macrophages increased with increasing cholesterol content in the diet. The numbers of CD163-positive macrophages and CD204-positive macrophages also increased with increasing cholesterol content in the diet; however, the proportion of CD204-positive macrophages among Iba-1-positive macrophages was significantly reduced by cholic acid supplementation.

Conclusion: The results suggest that lipid accumulation induced macrophage recruitment in swine livers, and that the number of M2-like macrophages increased at the early stage of NAFLD, while the number of M1-like macrophages increased at the late stage of NAFLD, resulting in a liver condition like non-alcoholic steatohepatitis. We provide evidence of the phenotypic changes that occur in macrophages during the development of NAFLD that has never been reported before using µMPs.

Expression of mucosal addressin cell adhesion molecule-1 on the reticular framework between white pulp and the marginal zone in the human spleen

The antigenic heterogeneity of the reticular framework of the white pulp and marginal zone is well documented in the human adult spleen. Immunostaining of α-smooth muscle actin characterizes the heterogeneity of the reticular framework of the white pulp and marginal zone. In the human spleen, the blood cells flow in an open circulation. T and B lymphocytes flow out from the arterial terminal, and migrate in the reticular framework. Homing of lymphocytes to lymphoid tissues is regulated by selective interactions between cell surface homing receptors and tissue vascular addressins at sites of lymphocyte recruitment from the blood. In the present study, mucosal addressin cell adhesion molecule-1 was selectively expressed on α-smooth muscle actin-positive reticular framework. The reticular framework may function in lymphocyte homing and segregation into the periarteriolar lymphoid sheath, lymph follicle and marginal zone.

Ki67 expression at Kasai portoenterostomy as a prognostic factor in patients with biliary atresia

Background

Biliary atresia is a rare paediatric biliary obliteration disease with unknown aetiology, and is the most common indication for paediatric liver transplantation (LT). However, no consensus for predicting Kasai portoenterostomy (KP) outcomes using liver histological findings exists. Ki67 is a popular biomarker for measuring and monitoring cellular proliferation.

Methods

Ki67 (clone, MIB‐1) liver parenchyma expression was measured by immunohistochemical staining of samples from living donors and patients with biliary atresia to assess its value in predicting outcomes after KP.

Results

Of 35 children with biliary atresia, 13 were native liver survivors (NLS), 17 were non‐NLS, and five had primary LT. The median proportion of Ki67 immunostained areas in donors and patients with biliary atresia at KP was 0·06 and 0·99 per cent respectively. Univariable analysis identified a high proportion of Ki67 areas, high Ki67 cell numbers and high Ki67‐positive/leucocyte common antigen‐positive cell numbers at KP as significant predictors of poor native liver survival after KP (hazard ratio 9·29, 3·37 and 12·17 respectively). The proportion of Ki67 areas in the non‐NLS group was significantly higher than that in the NLS group (1·29 versus 0·72 per cent respectively; P = 0·001), and then decreased at LT (0·32 per cent versus 1·29 per cent at KP; P < 0·001).

Conclusion

This study has demonstrated the clinical data and time course of Ki67 expression in patients with biliary atresia. High Ki67 expression at KP may be an important predictor of native liver survival following the procedure.

Targeting FROUNT with disulfiram suppresses macrophage accumulation and its tumor-promoting properties

Tumor-associated macrophages affect tumor progression and resistance to immune checkpoint therapy. Here, we identify the chemokine signal regulator FROUNT as a target to control tumor-associated macrophages. The low level FROUNT expression in patients with cancer correlates with better clinical outcomes. Frount-deficiency markedly reduces tumor progression and decreases macrophage tumor-promoting activity. FROUNT is highly expressed in macrophages, and its myeloid-specific deletion impairs tumor growth. Further, the anti-alcoholism drug disulfiram (DSF) acts as a potent inhibitor of FROUNT. DSF interferes with FROUNT-chemokine receptor interactions via direct binding to a specific site of the chemokine receptor-binding domain of FROUNT, leading to inhibition of macrophage responses. DSF monotherapy reduces tumor progression and decreases macrophage tumor-promoting activity, as seen in the case of Frount-deficiency. Moreover, co-treatment with DSF and an immune checkpoint antibody synergistically inhibits tumor growth. Thus, inhibition of FROUNT by DSF represents a promising strategy for macrophage-targeted cancer therapy.

The cytoplasmic protein FROUNT can bind to chemokine receptors and enhance chemokine signalling. Here, the authors show that inhibiting FROUNT in macrophages either by knockdown of the gene or using the anti-alcoholism drug disulfiram, results in a reduction in tumour growth.

Clinical and transcriptional signatures of human CD204 reveal an applicable marker for the protumor phenotype of tumor-associated macrophages in breast cancer

Background: Tumor-associated macrophages in human breast cancer are poorly understood. Specific tumor-associated macrophage-related molecular mechanisms among different intrinsic molecular subtypes remain unclear. Here, we have identified and explored the roles of the tumor-associated macrophages novel marker: CD204 in different subtypes of breast cancer.

Results: CD204 was upregulated in four subtypes of breast cancer, and this was associated with poor survival outcomes. CD204 could promote tumor cell proliferation, migration, and invasion and was involved in immune system-related pathways among all subtypes. Special pathways in each subtype were also found. High CD204 mRNA expressions were associated with high proportions of protumor immune cell populations, and most immunoinhibitors positive correlated with CD204 expression in all subtypes.

Conclusions: These findings contribute to a better understanding and managing the protumor phenotype of tumor-associated macrophages in different subtypes of breast cancer.

Methods: The expression of CD204 and its clinical outcome were analyzed. The roles of CD204 in the regulation of tumor cell proliferation, migration, and invasion were studied. Potential pathways influenced by CD204 were displayed. Immune cell infiltration in different CD204 mRNA expression status and correlations between CD204 and immunoinhibitors were also analyzed.

Maf expression in human macrophages and lymph node sinus macrophages in patients with esophageal cancer

The large Maf transcription factors are expressed in immune cells including macrophages and lymphocytes. To investigate the distribution of Maf expression in human organs, immunostaining for Maf was performed using sections of several human organs. High Maf expression was seen in the nucleus of macrophages in the gastrointestinal tract and lymph node sinus macrophages (LySMs). Then, we assessed whether Maf expression in LySMs was correlated with CD169 expression and the clinical prognosis in patients with esophageal cancer. Maf expression was associated with CD169 expression, but Maf expression in LySMs was not associated with the clinical course in patients with esophageal cancer. We determined which cytokines stimulate Maf expression using cultured macrophages. Immunocytochemistry showed that Maf expression was significantly elevated by interferon-γ. These results are the first report of Maf expression in human samples. Maf expression may be a marker for the macrophage population in humans.

Expression of IL-34 correlates with macrophage infiltration and prognosis of diffuse large B-cell lymphoma

Objectives

Infiltration of macrophages through the tyrosine kinase receptor CSF1R is a poor prognosis factor in various solid tumors. Indeed, these tumors produce CSF1R ligand, macrophage colony‐stimulating factor (M‐CSF) or interleukin‐34 (IL‐34). However, the significance of these cytokines, particularly, the newly discovered IL‐34 in haematological malignancies, is not fully understood. We therefore analysed the role of IL‐34 in diffuse large B‐cell lymphoma (DLBCL), the most common subtype of malignant lymphoma.

Methods

We analysed formalin‐fixed paraffin‐embedded lymphoma tissues of 135 DLBCL patients for the expression of IL‐34 and the number of macrophages, and the survival of these patients. The expression of IL‐34 in DLBCL cell lines and the activity of IL‐34 to induce the migration of monocytic cells were also characterised.

Results

Several lymphoma tissues showed a clear IL‐34 signal, and such signal was detectable in 36% of patients. DLBCL cell lines also expressed IL‐34. Interestingly, the percentage of IL‐34⁺ patients in the activated B‐cell subtype was significantly higher than that in the germinal centre B‐cell subtype. More interestingly, IL‐34⁺ patients showed shorter survival periods and higher number of macrophages in lymphoma tissues. The recruitment of monocytes is likely the first step for the higher macrophage density in the IL‐34⁺ lymphoma tissues. Indeed, IL‐34 induced the migration of monocytic cells.

Conclusion

Our results raise the possibility that IL‐34 in lymphoma tissues of DLBCL patients recruits monocytes, leading to the higher number of macrophages in the tissues and poor prognosis of patients. IL‐34 may be an additional therapeutic target of DLBCL.

Accurate expression of PD-L1/L2 in lung adenocarcinoma cells: A retrospective study by double immunohistochemistry

The percentage of programmed death ligand 1 (PD‐L1) positivity in cancer cells, named as the tumor proportion score, is considered to be a predictive biomarker for anti‐PD‐1/PD‐L1 therapy in lung cancer. PD‐L1 is expressed on not only cancer cells but also on immune cells, including macrophages. Although previous studies related to PD‐L1/2 expression in cancer tissues have been generally based on single immunohistochemistry (IHC), in the present study, we attempted to evaluate accurate PD‐L1/2 expression in cancer cells in lung adenocarcinoma cells using double IHC to also evaluate macrophages. Of the 231 patients, PD‐L1 expression was negative in 169 patients (73.2%), 1%‐49% positive in 47 patients (20.3%), and ≥50% positive in 15 patients (6.5%). Interestingly, PD‐L1 positivity was decreased when using double IHC compared with the estimation by single IHC. High PD‐L1 expression was associated with high‐grade cancer cells and in higher stage cancer. PD‐L2 was negative in 109 patients (47.2%), 1%‐49% positive in 50 patients (21.6%), and ≥50% positive in 72 patients (31.2%). The number of PD‐L2‐positive patients was increased in cases that had an epidermal growth factor receptor (EGFR) mutation and in lower stage cancer. Thirty‐five patients (15.2%) were positive for both PD‐L1 and PD‐L2, whereas 81 patients (35.1%) were negative for both PD‐L1 and PD‐L2. Log‐rank analysis showed that progression‐free survival and overall survival were significantly the longest in the PD‐L1‐negative and PD‐L2‐positive groups (P < .0001 and P = .0120). We observed lower PD‐L1 or PD‐L2 expression in lung adenocarcinoma than previously reported. Double IHC for macrophages may help clinicians to evaluate PD‐L1 or PD‐L2 expression specifically in cancer cells.

Histological analysis of infiltrating macrophages in the cerebral aneurysm walls

A series of recent evidences suggested activated macrophages have broadly two distinct forms that possess opposite functions for the process of inflammation: classically activated macrophages (M1/kill macrophages) and alternatively activated macrophages (M2/repair macrophages) according to their functions and expression markers. To elucidate what roles those two phenotypes of macrophages play in the evolution of cerebral aneurysm, the presence of macrophages inside the aneurysm walls was assessed with an immunohistochemical approach. The portions of the aneurysm domes deflated after neck clipping were utilized for the further histological examinations, including immunostainings with five antibodies to identify macrophage subpopulations. In this study, contrary to the previous reports, the following various ratios of subtypes were observed in the aneurysm walls: M1 > M2 (2 cases), M1 < M2 (2 cases), M1 = M2 (3 cases). While M1-like macrophages have been typically regarded as a main driver of the degenerating process, these surprisingly richer presences of M2-like macrophages in the aneurysm walls suggests that an unrecognized biological process might be in play in aneurysm development.

The significance of CD163-expressing macrophages in asthma

BACKGROUND

CD163 is one of the scavenger receptors that are specifically expressed on macrophages and are well known to be upregulated by various inflammatory responses, including chronic obstructive pulmonary disease in airway diseases.

OBJECTIVE

To evaluate the CD163 expression in the lungs of patients with fatal asthma and investigated whether CD163 contributes to the pathogenesis in asthma.

METHODS

The CD163 expressions in the lungs of patients with fatal asthma (n = 9) and in those of nonasthma control subjects (n = 8) were tested by immunohistochemistry. In mouse models of asthma, airway hyperresponsiveness (AHR) and the numbers of airway inflammatory cells in the bronchoalveolar lavage fluid (BALF) were analyzed in the CD163-deficient mice and the control wild-type mice.

RESULTS

The numbers of CD163-positive macrophages in the lung tissues were significantly increased in the all 6 patients with fatal asthma than in the control subjects. In mouse models of asthma, AHR and the numbers of infiltrating leukocytes, such as eosinophils, lymphocytes, neutrophils, and macrophages, in the BALF were significantly decreased in the CD163-deficient mice when compared with control wild-type mice. The concentrations of interferon γ and interleukin 5 in the BALF were significantly decreased in the CD163-deficient mice when compared with those in the control wild-type mice.

CONCLUSION

CD163 may play important roles in airway inflammation and AHR in asthma.

Stratifying nonfunctional pituitary adenomas into two groups distinguished by macrophage subtypes

Tumor-associated macrophages (TAMs) polarize to M1 and M2 subtypes exerting anti-tumoral and pro-tumoral effects, respectively. To date, little is known about TAMs, their subtypes, and their roles in non-functional pituitary adenomas (NFPAs). We performed flow cytometry on single cell suspensions from 16 NFPAs, revealing that CD11b⁺ myeloid cells comprise an average of 7.3% of cells in NFPAs (range = 0.5%–27.1%), with qPCR revealing most CD11b⁺ cells to be monocyte-derived TAMs rather than native microglia. The most CD11b-enriched NFPAs (10–27% CD11b⁺) were the most expansile (size>3.5 cm or MIB1>3%). Increasing CD11b⁺ fraction was associated with decreased M2 TAMs and increased M1 TAMs. All NFPAs with cavernous sinus invasion had M2/M1 gene expression ratios above one, while 80% of NFPAs without cavernous sinus invasion had M2/M1<1 (P = 0.02). Cultured M2 macrophages promoted greater invasion (P < 10^-5) and proliferation (P = 0.03) of primary NFPA cultures than M1 macrophages in a manner inhibited by siRNA targeting S100A9 and EZH2, respectively. Primary NFPA cultures were of two types: some recruited more monocytes in an MCP-1-dependent manner and polarized these to M2 TAMs, while others recruited fewer monocytes and polarized them to M1 TAMS in a GM-CSF-dependent manner. These findings suggest that TAM recruitment and polarization into the pro-tumoral M2 subtype drives NFPA proliferation and invasion. Robust M2 TAM infiltrate may occur during an NFPA growth phase before self-regulating into a slower growth phase with fewer overall TAMs and M1 polarization. Analyses like these could generate immunomodulatory therapies for NFPAs.

Tumour-associated macrophages are associated with poor prognosis and programmed death ligand 1 expression in oesophageal cancer

INTRODUCTION

Tumour-associated macrophages (TAMs) in tumour microenvironments promote cancer cell proliferation, immunosuppression and angiogenesis, leading to tumour growth and metastasis. TAMs have become increasingly recognised as a cancer therapy target, such as in combination therapy with an immunity checkpoint inhibitor. However, the clinical and prognostic features of TAMs, and the relationship between TAMs and programmed death ligand 1 (PD-L1), remain unexplored in oesophageal cancer.

METHODS

Using a non-biased database of 305 resected oesophageal cancer preparations, we evaluated the expression of two M2-like macrophage markers (CD163 and CD204) and PD-L1 on tumour cells by immunostaining. Through in vitro assays, we examined how TAMs influence phenotypic malignancy and PD-L1 expression.

RESULTS

High density of CD163 (n = 160) or CD204 (n = 146) was associated with significantly worse overall survival than low expression (log rank P = 0.0025 and 0.018 for CD163 and CD204, respectively). The prognostic effect of TAMs was not significantly modified by any clinical factors (P > 0.05 for all interactions). High TAM density was significantly associated with increased PD-L1 expression. In in vitro assays, cell invasion and migration ability were significantly more upregulated in oesophageal cancer cell lines cocultured with activated macrophages than in control cell lines. Coculture with activated macrophages elevated the PD-L1 expression in cancer cells.

CONCLUSIONS

High TAM density in oesophageal cancer tissues was associated with shorter survival, suggesting a prognostic biomarker role for TAMs. TAMs also increase PD-L1 expression in tumour cells. Given the significant interest in cancer immunotherapies targeting TAMs and PD-L1, the current findings should have considerable clinical implications.

Spred2 Regulates High Fat Diet-Induced Adipose Tissue Inflammation, and Metabolic Abnormalities in Mice

Chronic low-grade inflammation in visceral adipose tissues triggers the development of obesity-related insulin resistance, leading to the metabolic syndrome, a serious health condition with higher risk of cardiovascular disease, diabetes, and stroke. In the present study, we investigated whether Sprouty-related EVH1-domain-containing protein 2 (Spred2), a negative regulator of the Ras/Raf/ERK/MAPK pathway, plays a role in the development of high fat diet (HFD)-induced obesity, adipose tissue inflammation, metabolic abnormalities, and insulin resistance. Spred2 knockout (KO) mice, fed with HFD, exhibited an augmented body weight gain, which was associated with enhanced adipocyte hypertrophy in mesenteric white adipose tissue (mWAT) and deteriorated dyslipidemia, compared with wild-type (WT) controls. The number of infiltrating macrophages with a M1 phenotype, and the crown-like structures, composed of macrophages surrounding dead or dying adipocytes, were more abundant in Spred2 KO-mWAT compared to in WT-mWAT. Exacerbated adipose tissue inflammation in Spred2 KO mice led to aggravated insulin resistance and fatty liver disease. To analyze the mechanism(s) that caused adipose tissue inflammation, cytokine response in mWAT was investigated. Stromal vascular fraction that contained macrophages from Spred2 KO-mWAT showed elevated levels of tumor necrosis factor α (TNFα) and monocyte chemoattractant protein-1 (MCP-1/CCL2) compared with those from WT-mWAT. Upon stimulation with palmitate acid (PA), bone marrow-derived macrophages (BMDMs) derived from Spred2 KO mice secreted higher levels of TNFα and MCP-1 than those from WT mice with enhanced ERK activation. U0126, a MEK inhibitor, reduced the PA-induced cytokine response. Taken together, these results suggested that Spred2, in macrophages, negatively regulates high fat diet-induced obesity, adipose tissue inflammation, metabolic abnormalities, and insulin resistance by inhibiting the ERK/MAPK pathway. Thus, Spred2 represents a potential therapeutic tool for the prevention of insulin resistance and resultant metabolic syndrome.

Not CD68 but stabilin-1 expression is associated with the risk of recurrence in patients with oral cavity squamous cell carcinoma

BACKGROUND

This study's aim was to identify CD68 and stabilin-1 expressions and their prognostic implications in patients with oral cavity cancer (OCC).

METHODS

Stabilin-1 and CD68 immunochemical staining was conducted in samples from patients with OCC who underwent curative surgery in our institute. We retrospectively analyzed patients' clinical information. We investigated the relationship between CD68 and stabilin-1 expression levels and their effect on prognostic factors and survival.

RESULTS

Fifty-four patients' data were analyzed. CD68 and stabilin-1 expressions were positively correlated (P = .008). CD68 and stabilin-1 expressions were not correlated with other prognostic factors (eg, T classification or lymph node metastasis). Stabilin-1 expression and tumor recurrence risk were positively correlated (P = .015). CD68 expression was neither associated with recurrence-free nor OCC-specific survival.

CONCLUSION

CD68 and stabilin-1 expressions in OCC were positively correlated. Stabilin-1 expression was significantly associated with OCC recurrence risk, but the prognostic value of CD68 was not confirmed.

Potential anti-lymphoma effect of M-CSFR inhibitor in adult T-cell leukemia/lymphoma

The c-fms proto-oncogene is also known as macrophage colony stimulating factor receptor (M-CSFR) or colony-stimulating factor-1 receptor (CSF-1R), and is expressed on several types of malignant tumor cells and myeloid cells. In the present study, we found that overexpression of M-CSFR was present in adult T-cell leukemia/lymphoma (ATLL) cases. M-CSFR signaling was associated with lymphoma cell proliferation, and M-CSFR inhibition induced apoptosis in lymphoma cells. The ATLL cell line ATL-T expressed M-CSF/CSF-1 and interleukin (IL)-34, which are both M-CSFR ligands. M-CSF and IL-34 expression was seen in ATLL cases, and co-expression of these ligands was detected in 11 of 13 ATLL cases. M-CSFR inhibition suppressed programmed death-1 and -2 ligand in ATL-T cells and macrophages stimulated with conditioned medium from ATL-T cells. Thus, an M-CSFR inhibitor may be useful as additional therapy against ATLL due to direct and indirect mechanisms.

IL-13 Contributes to Drug Resistance of NK/T-Cell Lymphoma Cells by Regulating ABCC4

Background

Extranodal natural killer/T (NK/T) cell lymphoma, nasal type (ENKTL), represents a rare subtype of T-cell lymphomas with aggressive clinical behavior and is relatively resistant to chemotherapy. However, there is relatively poor understanding of molecular pathogenesis of multidrug resistance in ENKTL. Here, we aimed to explore the biological roles and potential mechanism of IL-13 and ABCC4 in multidrug resistance of NK/T-cell lymphoma.

Methods

ELISA analysis was used to determine the level of serum IL-13 and immunohistochemical analysis was applied to detect the ABCC4 expression level in patients with human NK/T-cell lymphoma. Western blot assay was employed to measure the expression of ABCC4 in cells. Lenti-sh-ABCC4 viruses were constructed to knock down ABCC4 in YTS cells. CCK-8 assay and flow cytometric analysis were performed to detect the effects of IL-13 and ABCC4 on cell proliferation and apoptosis. CCK-8 assay was conducted to detect the effect of IL-13 and ABCC4 on cell sensitivity to adriamycin (ADM) in YTS cells.

Results

Levels of serum IL-13 and ABCC4 expression were observed to be upregulated in patients with human NK/T-cell lymphoma. Moreover, ABCC4 protein expression was also increased in NK/T-cell lymphoma YTS cells compared to the normal NK cells. Interestingly, IL-13 promoted ABCC4 expression in YTS cells. IL-13 promoted proliferation and suppressed apoptosis of YTS cells and reversed the effects of ABCC4 knockdown on promotive proliferation and inhibitory apoptosis. In addition, IL-13 enhanced YTS cell chemotherapy resistance to ADM by promoting ABCC4 expression.

Conclusion

Our findings concluded that IL-13 inhibited chemotherapy sensitivity of NK/T-cell lymphoma cells by regulating ABCC4, disrupting which may effectively improve the therapy protocols against resistant NK/T-cell lymphoma.

Novel therapeutic strategies for advanced ovarian cancer by using induced pluripotent stem cell-derived myelomonocytic cells producing interferon beta

Although first‐line chemotherapy has a high rate of complete responses in ovarian cancer patients, the vast majority of patients present with recurrent disease that has become refractory to conventional chemotherapy. Peritoneal dissemination and malignant ascites are the hallmarks of recurrent or advanced ovarian cancer and severely reduce quality of life. Development of therapeutic measures to treat such patients is eagerly anticipated. Macrophage infiltration is observed in various types of cancer including epithelial ovarian cancer. In addition, macrophages are involved in the formation of spheroids in the malignant ascites of ovarian cancer and promote cancer growth. iPS‐ML, macrophage‐like myelomonocytic cells generated from human induced pluripotent stem (iPS) cells, made close contacts with ovarian cancer cells in vitro. We hypothesized that, if we inoculate iPS‐ML‐producing IFN‐β (iPS‐ML/IFN‐β) into the peritoneal cavity of patients with ovarian cancer, IFN‐β produced by the iPS‐ML/IFN‐β would efficiently act on the cancer cells to suppress cancer growth. To evaluate this hypothesis, we injected iPS‐ML/IFN‐β into SCID mice bearing peritoneally disseminated human ovarian cancer cells, SKOV3. Immunohistochemical analysis of the intraperitoneal tumors detected iPS‐ML/IFN‐β infiltrating into the cancer tissues. Therapy with iPS‐ML/IFN‐β significantly suppressed tumor progression. In addition, dramatic reduction of cancer‐related ascites was observed. Collectively, it is suggested that iPS‐ML/IFN‐β therapy offers a new approach for the treatment of patients with advanced ovarian cancer.

The expression of PD-1 ligands and IDO1 by macrophage/microglia in primary central nervous system lymphoma

Recent progress in anti-tumor immunotherapy has focused on the significance of the tumor microenvironment in tumor progression and resistance to chemo/radio-therapy. Myeloid cells such as macrophages are predominant stromal components in hematological malignancies. In the present study, we investigated the regulation of programmed death-1 (PD-1) ligand expression in primary central nervous system lymphoma (PCNSL) using PCNSL cell lines and human monocyte-derived macrophages. TK PCNSL cell line-derived soluble factors induced overexpression of PD-1 ligands, indoleamine 2,3-dioxygenase (IDO1), and several other cytokines in macrophages. The expression of PD-1 ligands was dependent on the activation of signal transducer and activator of transcription 3. PD-L1 and IDO1 were overexpressed by macrophage/microglia in PCNSL tissues, and gene expression profiling indicated that IDO1 expression was positively correlated with the expression of macrophage and lymphocyte markers. Macrophage-derived factors did not influence the proliferation or chemo-sensitivity of cell lines. These data suggest that the expression of immunosuppressive molecules, including PD-1 ligands and IDO1, by macrophage/microglia may be involved in immune evasion of lymphoma cells.

CD169-positive sinus macrophages in the lymph nodes determine bladder cancer prognosis

CD169⁺ macrophages are suggested to play a pivotal role in establishing anti‐tumor immunity. They capture dead tumor cell‐associated antigens and transfer their information to lymphocsytes, including CD8⁺ T cells, which is important for successful tumor suppression. This study aimed to determine the prognostic significance of CD169⁺ macrophages residing in the tumor‐draining lymph nodes from cases of bladder cancer. In this retrospective study, 44 bladder cancer patients who received radical cystectomy were examined. The abundance of CD169⁺ macrophages in the regional lymph nodes and the number of CD8⁺ T cells in the primary tumor were investigated by immunohistochemistry. A CD169 score was calculated based on the intensity of CD169 staining and the proportion of CD169⁺ macrophages, and the scores were compared to the patients’ clinicopathological parameters. A high CD169 score was significantly associated with low T stage and with a high number of CD8⁺ T cells infiltrating into the tumor. The group with high CD169 expression had significantly longer cancer‐specific survival than the group with low CD169 expression (5‐year cancer‐specific survival rate: 83.3% vs 31.3%). In a multivariate analysis, the CD169 score was identified as a strong and independent favorable prognostic factor for cancer‐specific survival. Our findings suggest that CD169⁺ macrophages in the lymph nodes enhance anti‐tumor immunity by expanding CD8⁺ T cells in bladder cancer. The CD169 score may serve as a novel marker for the evaluation of bladder cancer prognosis.

Sirtuin 7 Deficiency Ameliorates Cisplatin-induced Acute Kidney Injury Through Regulation of the Inflammatory Response

Cisplatin-induced acute kidney injury (AKI) has been recognized as one of cisplatin’s serious side effects, limiting its use in cancer therapy. Sirtuin 1 (SIRT1) and SIRT3 play protective roles against cisplatin-induced kidney injury. However, the role of SIRT7 in cisplatin-induced kidney injury is not yet known. In this study, we found that Sirt7 knockout (KO) mice were resistant to cisplatin-induced AKI. Furthermore, our studies identified that loss of SIRT7 decreases the expression of tumor necrosis factor-α (TNF-α) by regulating the nuclear expression of the transcription factor nuclear factor kappa B. It has been reported that cisplatin-induced nephrotoxicity is mediated by TNF-α. Our results indicate that SIRT7 plays an important role in cisplatin-induced AKI and suggest the possibility of SIRT7 as a novel therapeutic target for cisplatin-induced nephrotoxicity.

Myeloid ERK5 deficiency suppresses tumor growth by blocking protumor macrophage polarization via STAT3 inhibition

Macrophages can be functionally reprogrammed by the tumor microenvironment to further tumor growth and malignancy. In this study, we have discovered that this pathological process is dependent on the ERK5 MAPK. Accordingly, we demonstrated that inactivation of ERK5 in macrophages blocked the phosphorylation of STAT3, a transcription factor crucial for determining macrophage polarity, and impaired the growth of melanoma and carcinoma grafts. These results raise the possibility that targeting protumor macrophages via anti-ERK5 therapy constitutes a very attractive strategy for cancer treatment. This is important given that the detection of large numbers of macrophages in human tumors often correlates with poor prognosis, but also with a poor response of the tumor to anticancer agents.

Owing to the prevalence of tumor-associated macrophages (TAMs) in cancer and their unique influence upon disease progression and malignancy, macrophage-targeted interventions have attracted notable attention in cancer immunotherapy. However, tractable targets to reduce TAM activities remain very few and far between because the signaling mechanisms underpinning protumor macrophage phenotypes are largely unknown. Here, we have investigated the role of the extracellular-regulated protein kinase 5 (ERK5) as a determinant of macrophage polarity. We report that the growth of carcinoma grafts was halted in myeloid ERK5-deficient mice. Coincidentally, targeting ERK5 in macrophages induced a transcriptional switch in favor of proinflammatory mediators. Further molecular analyses demonstrated that activation of the signal transducer and activator of transcription 3 (STAT3) via Tyr705 phosphorylation was impaired in erk5-deleted TAMs. Our study thus suggests that blocking ERK5 constitutes a treatment strategy to reprogram macrophages toward an antitumor state by inhibiting STAT3-induced gene expression.

Phenotypical change of tumor-associated macrophages in metastatic lesions of clear cell renal cell carcinoma

Macrophages are the main immune cells of the tumor microenvironment in clear cell renal cell carcinoma (ccRCC). A high density of CD163⁺ or CD204⁺ tumor-associated macrophages (TAMs), rather than the density of total TAMs, is known to be linked to poor clinical outcome. In the present study, we investigated the phenotypical differences between the paired primary and metastatic lesions in ccRCC cases. Using immunostaining, the densities of CD163⁺ and CD204⁺ TAMs in metastatic lesions were found to be significantly lower compared to primary lesions, although the total number of TAMs was increased in metastatic lesions. Since CD163 and CD204 are considered to be the markers of an M2/protumor phenotype in macrophages, TAMs in metastatic lesions are suggested to have a greater M1/inflammatory function compared with those from primary lesions. These findings give new insights in regard to the immunological status of metastatic lesions of ccRCC.