The role of macrophage-derived IL-1 in induction and maintenance of angiogenesis

Macrophages in cardiovascular diseases: molecular mechanisms and therapeutic targets

The immune response holds a pivotal role in cardiovascular disease development. As multifunctional cells of the innate immune system, macrophages play an essential role in initial inflammatory response that occurs following cardiovascular injury, thereby inducing subsequent damage while also facilitating recovery. Meanwhile, the diverse phenotypes and phenotypic alterations of macrophages strongly associate with distinct types and severity of cardiovascular diseases, including coronary heart disease, valvular disease, myocarditis, cardiomyopathy, heart failure, atherosclerosis and aneurysm, which underscores the importance of investigating macrophage regulatory mechanisms within the context of specific diseases. Besides, recent strides in single-cell sequencing technologies have revealed macrophage heterogeneity, cell-cell interactions, and downstream mechanisms of therapeutic targets at a higher resolution, which brings new perspectives into macrophage-mediated mechanisms and potential therapeutic targets in cardiovascular diseases. Remarkably, myocardial fibrosis, a prevalent characteristic in most cardiac diseases, remains a formidable clinical challenge, necessitating a profound investigation into the impact of macrophages on myocardial fibrosis within the context of cardiac diseases. In this review, we systematically summarize the diverse phenotypic and functional plasticity of macrophages in regulatory mechanisms of cardiovascular diseases and unprecedented insights introduced by single-cell sequencing technologies, with a focus on different causes and characteristics of diseases, especially the relationship between inflammation and fibrosis in cardiac diseases (myocardial infarction, pressure overload, myocarditis, dilated cardiomyopathy, diabetic cardiomyopathy and cardiac aging) and the relationship between inflammation and vascular injury in vascular diseases (atherosclerosis and aneurysm). Finally, we also highlight the preclinical/clinical macrophage targeting strategies and translational implications.

Navigating tumor angiogenesis: therapeutic perspectives and myeloid cell regulation mechanism

Sustained angiogenesis stands as a hallmark of cancer. The intricate vascular tumor microenvironment fuels cancer progression and metastasis, fosters therapy resistance, and facilitates immune evasion. Therapeutic strategies targeting tumor vasculature have emerged as transformative for cancer treatment, encompassing anti-angiogenesis, vessel normalization, and endothelial reprogramming. Growing evidence suggests the dynamic regulation of tumor angiogenesis by infiltrating myeloid cells, such as macrophages, myeloid-derived suppressor cells (MDSCs), and neutrophils. Understanding these regulatory mechanisms is pivotal in paving the way for successful vasculature-targeted cancer treatments. Therapeutic interventions aimed to disrupt myeloid cell-mediated tumor angiogenesis may reshape tumor microenvironment and overcome tumor resistance to radio/chemotherapy and immunotherapy.

Exploring the multifaceted effects of Interleukin-1 in lung cancer: From tumor development to immune modulation

Lung cancer, acknowledged as one of the most fatal cancers globally, faces limited treatment options on an international scale. The success of clinical treatment is impeded by challenges such as late diagnosis, restricted treatment alternatives, relapse, and the emergence of drug resistance. This predicament has led to a saturation point in lung cancer treatment, prompting a rapid shift in focus towards the tumor microenvironment (TME) as a pivotal area in cancer research. Within the TME, Interleukin-1 (IL-1) is abundantly present, originating from immune cells, tissue stromal cells, and tumor cells. IL-1's induction of pro-inflammatory mediators and chemokines establishes an inflammatory milieu influencing tumor occurrence, development, and the interaction between tumors and the host immune system. Notably, IL-1 expression in the TME exhibits characteristics such as staging, tissue specificity, and functional pluripotency. This comprehensive review aims to delve into the impact of IL-1 on lung cancer, encompassing aspects of occurrence, invasion, metastasis, immunosuppression, and immune surveillance. The ultimate goal is to propose a novel treatment approach, considering the intricate dynamics of IL-1 within the TME.

Harnessing strategies for enhancing diabetic wound healing from the perspective of spatial inflammation patterns

Diabetic wound is a great threat to patient's health and lives. The refractory diabetic wound shows spatial inflammation patterns, in which the early-wound pattern depicts a deprived acute inflammatory response, and the long-term non-healing wound pattern delineates an excessive and persistent inflammation due to the delayed immune cell infiltration in a positive feedback loop. In this work, we give points to some strategies to normalize the dysregulated immune process based on the spatial inflammation pattern differences in diabetic wound healing. First of all, inhibiting inflammatory response to avoid subsequent persistent and excessive immune infiltration for the early diabetic wound is proposed. However, diabetic wounds are unperceptive trauma that makes patients miss the best treatment time. Therefore, we also introduce two strategies for the long-term non-healing diabetic wound. One strategy is about changing chronic wounds to acute ones, which aims to rejuvenate M1 macrophages in diabetic wounds and make spontaneous M2 polarization possible. To activate the controllable proinflammatory response, western medicine delivers proinflammatory molecules while traditional Chinese medicine develops "wound-pus promoting granulation tissue growth theory". Another strategy to solve long-term non-healing wounds is seeking switches that target M1/M2 transition directly. These investigations draw a map that delineates strategies for enhancing diabetic wound healing from the perspective of spatial inflammation patterns systematically.

Divergent Actions of Renal Tubular and Endothelial Type 1 IL-1 Receptor Signaling in Toxin-Induced AKI

SIGNIFICANCE STATEMENT

Activation of the type 1 IL-1 receptor (IL-1R1) triggers a critical innate immune signaling cascade that contributes to the pathogenesis of AKI. However, blockade of IL-1 signaling in AKI has not consistently demonstrated kidney protection. The current murine experiments show that IL-1R1 activation in the proximal tubule exacerbates toxin-induced AKI and cell death through local suppression of apolipoprotein M. By contrast, IL-1R1 activation in endothelial cells ameliorates AKI by restoring VEGFA-dependent endothelial cell viability. Using this information, future delivery strategies can maximize the protective effects of blocking IL-1R1 while mitigating unwanted actions of IL-1R1 manipulation.

BACKGROUND

Activation of the type 1 IL-1 receptor (IL-1R1) triggers a critical innate immune signaling cascade that contributes to the pathogenesis of AKI. IL-1R1 is expressed on some myeloid cell populations and on multiple kidney cell lineages, including tubular and endothelial cells. Pharmacological inhibition of the IL-1R1 does not consistently protect the kidney from injury, suggesting there may be complex, cell-specific effects of IL-1R1 stimulation in AKI.

METHODS

To examine expression of IL-1 and IL-1R1 in intrinsic renal versus infiltrating immune cell populations during AKI, we analyzed single-cell RNA sequencing (scRNA-seq) data from kidney tissues of humans with AKI and mice with acute aristolochic acid exposure. We then investigated cell-specific contributions of renal IL-1R1 signaling to AKI using scRNA-seq, RNA microarray, and pharmacological interventions in mice with IL-1R1 deletion restricted to the proximal tubule or endothelium.

RESULTS

scRNA-seq analyses demonstrated robust IL-1 expression in myeloid cell populations and low-level IL-1R1 expression in kidney parenchymal cells during toxin-induced AKI. Our genetic studies showed that IL-1R1 activation in the proximal tubule exacerbated toxin-induced AKI and cell death through local suppression of apolipoprotein M. By contrast, IL-1R1 activation in endothelial cells ameliorated aristolochic acid-induced AKI by restoring VEGFA-dependent endothelial cell viability and density.

CONCLUSIONS

These data highlight opposing cell-specific effects of IL-1 receptor signaling on AKI after toxin exposure. Disrupting pathways activated by IL-1R1 in the tubule, while preserving those triggered by IL-1R1 activation on endothelial cells, may afford renoprotection exceeding that of global IL-1R1 inhibition while mitigating unwanted actions of IL-1R1 blockade.

Circulating extracellular vesicles are monitoring biomarkers of anti-PD1 response and enhancer of tumor progression and immunosuppression in metastatic melanoma

BACKGROUND

Clinical drawback in checkpoint inhibitors immunotherapy (ICI) of metastatic melanoma (MM) is monitoring clinical benefit. Soluble forms of PD1(sPD1) and PD-L1(sPD-L1) and extracellular vesicles (EVs) expressing PD1 and PD-L1 have recently emerged as predictive biomarkers of response. As factors released in the blood, EVs and soluble forms could be relevant in monitoring treatment efficacy and adaptive resistance to ICI.

METHODS

We used pre-therapy plasma samples of 110 MM patients and longitudinal samples of 46 patients. Elisa assay and flow cytometry (FCM) were used to measure sPD-L1 and sPD1 concentrations and the percentage of PD1+ EVs and PD-L1+ EVs, released from tumor and immune cells in patients subsets. Transwell assays were conducted to investigate the impact of EVs of each patient subset on MM cells invasion and interaction between tumor cells and macrophages or dendritic cells. Viability assays were performed to assess EVs effect on MM cells and organoids sensitivity to anti-PD1. FCM was used to investigate immunosuppressive markers in EVs and immune cells.

RESULTS

The concentrations of sPD1 and sPD-L1 in pre-treatment and longitudinal samples did not correlate with anti-PD1 response, instead only tumor-derived PD1+ EVs decreased in long responders while increased during disease progression in responders. Notably, we observed reduction of T cell derived EVs expressing LAG3+ and PD1+ in long responders and their increase in responders experiencing progression. By investigating the impact of EVs on disease progression, we found that those isolated from non-responders and from patients with progression disease accelerated tumor cells invasiveness and migration towards macrophages, while EVs of long responders reduced the metastatic potential of MM cells and neo-angiogenesis. Additionally, the EVs of non-responders and of progression disease patients subset reduced the sensitivity of MM cells and organoids of responder to anti-PD1 and the recruitment of dendritic cells, while the EVs of progression disease subset skewed macrophages to express higher level of PDL-1.

CONCLUSION

Collectively, we suggest that the detection of tumor-derived PD1 + EVs may represent a useful tool for monitoring the response to anti-PD1 and a role for EVs shed by tumor and immune cells in promoting tumor progression and immune dysfunction.

Beyond VEGF: Targeting Inflammation and Other Pathways for Treatment of Retinal Disease

Neovascular eye diseases include conditions such as retinopathy of prematurity, proliferative diabetic retinopathy, and neovascular age-related macular degeneration. Together, they are a major cause of vision loss and blindness worldwide. The current therapeutic mainstay for these diseases is intravitreal injections of biologics targeting vascular endothelial growth factor (VEGF) signaling. Lack of universal response to these anti-VEGF agents coupled with the challenging delivery method underscore a need for new therapeutic targets and agents. In particular, proteins that mediate both inflammatory and proangiogenic signaling are appealing targets for new therapeutic development. Here, we review agents currently in clinical trials and highlight some promising targets in preclinical and early clinical development, focusing on the redox-regulatory transcriptional activator APE1/Ref-1, the bioactive lipid modulator soluble epoxide hydrolase, the transcription factor RUNX1, and others. Small molecules targeting each of these proteins show promise for blocking neovascularization and inflammation. The affected signaling pathways illustrate the potential of new antiangiogenic strategies for posterior ocular disease. SIGNIFICANCE STATEMENT: Discovery and therapeutic targeting of new angiogenesis mediators is necessary to improve treatment of blinding eye diseases like retinopathy of prematurity, diabetic retinopathy, and neovascular age-related macular degeneration. Novel targets undergoing evaluation and drug discovery work include proteins important for both angiogenesis and inflammation signaling, including APE1/Ref-1, soluble epoxide hydrolase, RUNX1, and others.

Exploring immune interactions in triple negative breast cancer: IL-1β inhibition and its therapeutic potential

Triple negative breast cancer (TNBC) has poor prognosis when compared to other breast cancer subtypes. Despite pre-clinical data supporting an immune targeted approach for TNBCs, immunotherapy has failed to demonstrate the impressive responses seen in other solid tumor malignancies. Additional strategies to modify the tumor immune microenvironment and potentiate response to immunotherapy are needed. In this review, we summarise phase III data supporting the use of immunotherapy for TNBC. We discuss the role of IL-1β in tumorigenesis and summarize pre-clinical data supporting IL-1β inhibition as a potential therapeutic strategy in TNBC. Finally, we present current trials evaluating IL-1β in breast cancer and other solid tumor malignancies and discuss future studies that may provide a strong scientific rationale for the combination of IL-1β and immunotherapy in the neoadjuvant and metastatic setting for people with TNBC.

The protective effects of a novel AT2 receptor agonist, β-Pro7Ang III in ischemia-reperfusion kidney injury

BACKGROUND AND PURPOSE

This study investigated the reno-protective effects of a highly selective AT₂R agonist peptide, β-Pro⁷Ang III in a mouse model of acute kidney injury (AKI).

METHODS

C57BL/6 J mice underwent either sham surgery or unilateral kidney ischemia-reperfusion injury (IRI) for 40 min. IRI mice were treated with either β-Pro⁷Ang III or perindopril and at 7 days post-surgery the kidneys analysed for histopathology and the development of fibrosis and matrix metalloproteinase (MMP)-2 and -9 activity. The association of the therapeutic effects of β-Pro⁷Ang III with macrophage number and phenotype was determined in vivo and in vitro.

KEY RESULTS

Decreased kidney tubular injury, interstitial matrix expansion and reduced interstitial immune cell infiltration in IRI mice receiving β-Pro⁷Ang III treatment was observed at day 7, compared to IRI mice without treatment. This correlated to reduced collagen accumulation and MMP-2 activity in IRI mice following β-Pro⁷Ang III treatment. FACS analysis showed a reduced number and proportion of CD45⁺CD11b⁺F4/80⁺ macrophages in IRI kidneys in response to β-Pro⁷Ang III, correlating with a significant increase in M2 macrophage markers and decreased M1 markers at day 3 and 7 post-IR injury, respectively. In vitro analysis of cultured THP-1 cells showed that β-Pro⁷Ang III attenuated lipopolysaccharide (LPS)-induced tumour necrosis factor-α (TNF-α) and interleukin (IL)- 6 production but increased IL-10 secretion, compared to LPS alone.

CONCLUSION

Administration of β-Pro⁷Ang III via mini-pump improved kidney structure and reduced interstitial collagen accumulation, in parallel with an alteration of macrophage phenotype and anti-inflammatory cytokine release, therefore mitigating the downstream progression of ischemic AKI.

Involvement of inflammasomes in tumor microenvironment and tumor therapies

Inflammasomes are macromolecular platforms formed in response to damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns, whose formation would cause maturation of interleukin-1 (IL-1) family members and gasdermin D (GSDMD), leading to IL-1 secretion and pyroptosis respectively. Several kinds of inflammasomes detecting different types of dangers have been found. The activation of inflammasomes is regulated at both transcription and posttranscription levels, which is crucial in protecting the host from infections and sterile insults. Present findings have illustrated that inflammasomes are involved in not only infection but also the pathology of tumors implying an important link between inflammation and tumor development. Generally, inflammasomes participate in tumorigenesis, cell death, metastasis, immune evasion, chemotherapy, target therapy, and radiotherapy. Inflammasome components are upregulated in some tumors, and inflammasomes can be activated in cancer cells and other stromal cells by DAMPs, chemotherapy agents, and radiation. In some cases, inflammasomes inhibit tumor progression by initiating GSDMD-mediated pyroptosis in cancer cells and stimulating IL-1 signal-mediated anti-tumor immunity. However, IL-1 signal recruits immunosuppressive cell subsets in other cases. We discuss the conflicting results and propose some possible explanations. Additionally, we also summarize interventions targeting inflammasome pathways in both preclinical and clinical stages. Interventions targeting inflammasomes are promising for immunotherapy and combination therapy.

Extracellular vesicles released from macrophages modulates interleukin-1β in astrocytic and neuronal cells

We have recently demonstrated that long-term exposure of cigarette smoke condensate (CSC) to HIV-uninfected (U937) and -infected (U1) macrophages induce packaging of pro-inflammatory molecules, particularly IL-1β, in extracellular vesicles (EVs). Therefore, we hypothesize that exposure of EVs derived from CSC-treated macrophages to CNS cells can increase their IL-1β levels contributing to neuroinflammation. To test this hypothesis, we treated the U937 and U1 differentiated macrophages once daily with CSC (10 µg/ml) for 7 days. Then, we isolated EVs from these macrophages and treated these EVs with human astrocytic (SVGA) and neuronal (SH-SY5Y) cells in the absence and presence of CSC. We then examined the protein expression of IL-1β and oxidative stress related proteins, cytochrome P450 2A6 (CYP2A6), superoxide dismutase-1 (SOD1), catalase (CAT). We observed that the U937 cells have lower expression of IL-1β compared to their respective EVs, confirming that most of the produced IL-1β are packaged into EVs. Further, EVs isolated from HIV-infected and uninfected cells, both in the absence and presence of CSC, were treated to SVGA and SH-SY5Y cells. These treatments showed a significant increase in the levels of IL-1β in both SVGA and SH-SY5Y cells. However, under the same conditions, the levels of CYP2A6, SOD1, and catalase were only markedly altered. These findings suggest that the macrophages communicate with astrocytes and neuronal cells via EVs-containing IL-1β in both HIV and non-HIV setting and could contribute to neuroinflammation.

Crosstalk of Inflammatory Cytokines within the Breast Tumor Microenvironment

Several immune and immunocompetent cells, including dendritic cells, macrophages, adipocytes, natural killer cells, T cells, and B cells, are significantly correlated with the complex discipline of oncology. Cytotoxic innate and adaptive immune cells can block tumor proliferation, and others can prevent the immune system from rejecting malignant cells and provide a favorable environment for tumor progression. These cells communicate with the microenvironment through cytokines, a chemical messenger, in an endocrine, paracrine, or autocrine manner. These cytokines play an important role in health and disease, particularly in host immune responses to infection and inflammation. They include chemokines, interleukins (ILs), adipokines, interferons, colony-stimulating factors (CSFs), and tumor necrosis factor (TNF), which are produced by a wide range of cells, including immune cells, such as macrophages, B-cells, T-cells, and mast cells, as well as endothelial cells, fibroblasts, a variety of stromal cells, and some cancer cells. Cytokines play a crucial role in cancer and cancer-related inflammation, with direct and indirect effects on tumor antagonistic or tumor promoting functions. They have been extensively researched as immunostimulatory mediators to promote the generation, migration and recruitment of immune cells that contribute to an effective antitumor immune response or pro-tumor microenvironment. Thus, in many cancers such as breast cancer, cytokines including leptin, IL-1B, IL-6, IL-8, IL-23, IL-17, and IL-10 stimulate while others including IL-2, IL-12, and IFN-γ, inhibit cancer proliferation and/or invasion and enhance the body's anti-tumor defense. Indeed, the multifactorial functions of cytokines in tumorigenesis will advance our understanding of cytokine crosstalk pathways in the tumor microenvironment, such as JAK/STAT, PI3K, AKT, Rac, MAPK, NF-κB, JunB, cFos, and mTOR, which are involved in angiogenesis, cancer proliferation and metastasis. Accordingly, targeting and blocking tumor-promoting cytokines or activating and amplifying tumor-inhibiting cytokines are considered cancer-directed therapies. Here, we focus on the role of the inflammatory cytokine system in pro- and anti-tumor immune responses, discuss cytokine pathways involved in immune responses to cancer and some anti-cancer therapeutic applications.

Decreased Expression of Soluble Epoxide Hydrolase Suppresses Murine Choroidal Neovascularization

Neovascular or "wet" age-related macular degeneration (nAMD) is a leading cause of blindness among older adults. Choroidal neovascularization (CNV) is a major pathological feature of nAMD, in which abnormal new blood vessel growth from the choroid leads to irreversible vision loss. There is a critical need to develop novel therapeutic strategies to address limitations of the current anti-vascular endothelial growth factor biologics. Previously, we identified soluble epoxide hydrolase (sEH) as a possible therapeutic target for CNV through a forward chemical genetic approach. The purpose of this study was to validate sEH as a target by examining retinal expression of sEH protein and mRNA by immunohistochemistry and RNAscope in situ hybridization, respectively, and to assess the efficacy of an adeno-associated virus (AAV) vector designed to knock down the sEH gene, Ephx2, in the murine laser-induced (L-) CNV model. nAMD patient postmortem eye tissue and murine L-CNV showed overexpression of sEH in photoreceptors and retinal pigment epithelial cells. Ephx2 knockdown significantly reduced CNV and normalized mRNA expression levels of CNV-related inflammatory markers. Thus, this study further establishes sEH as a promising therapeutic target against CNV associated with nAMD.

Macrophages play a key role in tissue repair and regeneration

Tissue regeneration after body injury has always been a complex problem to resolve for mammals. In adult mammals, the repair process after tissue injury is often accompanied by continuous and extensive fibrosis, which leads to scars. This process has been shown to severely hinder regeneration. Macrophages, as widely distributed innate immune cells, not only play an important role in various pathological processes, but also participate in the repair process before tissue regeneration and coordinate the regeneration process after repair. This review will discuss the various forms and indispensability of macrophages involved in repair and regeneration, and how macrophages play a role in the repair and regeneration of different tissues.

Trichinella Infection Ameliorated Vincristine-Induced Neuroinflammation in Mice

Vincristine (VCR) is a chemotherapeutic agent widely used in treatment of malignancies. However, VCR has a limitation in use since it commonly causes a painful neuropathy (VCR-induced peripheral neuropathy, VIPN). Inflammatory cytokines secreted by immune cells such as macrophages can exacerbate allodynia and hyperalgesia, because inhibiting the inflammatory response is a treatment target for VIPN. In this study, we investigated whether Trichinella spiralis, a widely studied helminth for its immunomodulatory abilities, can alleviate VCR-induced allodynia. Von Frey test showed that T. spiralis infection improved mechanical allodynia at 10 days after VCR injection. We further observed whether the difference was due to mitigated axon degeneration, but no significant difference between the groups in axonal degeneration in sciatic nerves and intra-epidermal nerve fibers was found. Conversely, we observed that number of infiltrated macrophages was decreased in the sciatic nerves of the T. spiralis infected mice. Moreover, treatment of T. spiralis excretory-secretory products caused peritoneal macrophages to secrete decreased level of IL-1β. This study suggests that T. spiralis can relieve VCR-induced mechanical allodynia by suppressing neuroinflammation and that application of controllable degree of helminth may prove beneficial for VIPN treatment.

The systemic-level repercussions of cancer-associated inflammation mediators produced in the tumor microenvironment

The tumor microenvironment is a dynamic, complex, and redundant network of interactions between tumor, immune, and stromal cells. In this intricate environment, cells communicate through membrane-membrane, ligand-receptor, exosome, soluble factors, and transporter interactions that govern cell fate. These interactions activate the diverse and superfluous signaling pathways involved in tumor promotion and progression and induce subtle changes in the functional activity of infiltrating immune cells. The immune response participates as a selective pressure in tumor development. In the early stages of tumor development, the immune response exerts anti-tumor activity, whereas during the advanced stages, the tumor establishes mechanisms to evade the immune response, eliciting a chronic inflammation process that shows a pro-tumor effect. The deregulated inflammatory state, in addition to acting locally, also triggers systemic inflammation that has repercussions in various organs and tissues that are distant from the tumor site, causing the emergence of various symptoms designated as paraneoplastic syndromes, which compromise the response to treatment, quality of life, and survival of cancer patients. Considering the tumor-host relationship as an integral and dynamic biological system, the chronic inflammation generated by the tumor is a communication mechanism among tissues and organs that is primarily orchestrated through different signals, such as cytokines, chemokines, growth factors, and exosomes, to provide the tumor with energetic components that allow it to continue proliferating. In this review, we aim to provide a succinct overview of the involvement of cancer-related inflammation at the local and systemic level throughout tumor development and the emergence of some paraneoplastic syndromes and their main clinical manifestations. In addition, the involvement of these signals throughout tumor development will be discussed based on the physiological/biological activities of innate and adaptive immune cells. These cellular interactions require a metabolic reprogramming program for the full activation of the various cells; thus, these requirements and the by-products released into the microenvironment will be considered. In addition, the systemic impact of cancer-related proinflammatory cytokines on the liver-as a critical organ that produces the leading inflammatory markers described to date-will be summarized. Finally, the contribution of cancer-related inflammation to the development of two paraneoplastic syndromes, myelopoiesis and cachexia, will be discussed.

Cancer combination therapies by angiogenesis inhibitors; a comprehensive review

Abnormal vasculature is one of the most conspicuous traits of tumor tissue, largely contributing to tumor immune evasion. The deregulation mainly arises from the potentiated pro-angiogenic factors secretion and can also target immune cells' biological events, such as migration and activation. Owing to this fact, angiogenesis blockade therapy was established to fight cancer by eliminating the nutrient and oxygen supply to the malignant cells by impairing the vascular network. Given the dominant role of vascular-endothelium growth factor (VEGF) in the angiogenesis process, the well-known anti-angiogenic agents mainly depend on the targeting of its actions. However, cancer cells mainly show resistance to anti-angiogenic agents by several mechanisms, and also potentiated local invasiveness and also distant metastasis have been observed following their administration. Herein, we will focus on clinical developments of angiogenesis blockade therapy, more particular, in combination with other conventional treatments, such as immunotherapy, chemoradiotherapy, targeted therapy, and also cancer vaccines. Video abstract.

Multi-Omics Reveals Different Strategies in the Immune and Metabolic Systems of High-Yielding Strains of Laying Hens

Lohmann Brown (LB) and Lohmann Selected Leghorn (LSL) are two commercially important laying hen strains due to their high egg production and excellent commercial suitability. The present study integrated multiple data sets along the genotype-phenotype map to better understand how the genetic background of the two strains influences their molecular pathways. In total, 71 individuals were analyzed (LB, n = 36; LSL, n = 35). Data sets include gut miRNA and mRNA transcriptome data, microbiota composition, immune cells, inositol phosphate metabolites, minerals, and hormones from different organs of the two hen strains. All complex data sets were pre-processed, normalized, and compatible with the mixOmics platform. The most discriminant features between two laying strains included 20 miRNAs, 20 mRNAs, 16 immune cells, 10 microbes, 11 phenotypic traits, and 16 metabolites. The expression of specific miRNAs and the abundance of immune cell types were related to the enrichment of immune pathways in the LSL strain. In contrast, more microbial taxa specific to the LB strain were identified, and the abundance of certain microbes strongly correlated with host gut transcripts enriched in immunological and metabolic pathways. Our findings indicate that both strains employ distinct inherent strategies to acquire and maintain their immune and metabolic systems under high-performance conditions. In addition, the study provides a new perspective on a view of the functional biodiversity that emerges during strain selection and contributes to the understanding of the role of host–gut interaction, including immune phenotype, microbiota, gut transcriptome, and metabolome.

AllergoOncology: Role of immune cells and immune proteins

Background

Immune cells and immune proteins play a pivotal role in host responses to pathogens, allergens and cancer. Understanding the crosstalk between allergic response and cancer, immune surveillance, immunomodulation, role of immunoglobulin E (IgE)‐mediated functions and help to develop novel therapeutic strategies. Allergy and oncology show two opposite scenarios: whereas immune tolerance is desired in allergy, it is detrimental in cancer.

Aim

The current review provides an update on the role of immune cells and immune proteins in allergy and cancer fields.

Methods

Authors investigated the role of relevant immunological markers and the correlation with cancer progression or cancer suppression.

Results

Activated immune cells such as macrophages ‘M1’, dendritic cells (DCs), innate lymphoid cells (ILC2), NK cells, Th1, follicular T helper cells (TFH), TCD8+, B lymphocytes and eosinophils have inhibitory effects on tumourigenesis, while tolerogenic cells such as macrophages ‘M2,’ tolerogenic DCs, ILC3, T and B regulatory lymphocytes appear to favour carcinogenesis. Mastocytes and alarmins can have both effects. RIgE antibodies and CCCL5 chemokine have an anticancer role, whereas IgG4, free light chains, Il‐10, TGF‐β, lipocalin‐2, CCL1 chemokine promote cancer progression. Fundamental is also the contribution of epigenetic changes regulated by the microRNA in cancer progression.

Conclusion

This knowledge represents the key to developing new anticancer therapies.

The Good, the Bad, and the Ugly: Neutrophils, Angiogenesis, and Cancer

Angiogenesis, the formation of new blood vessels from already existing vasculature, is tightly regulated by pro- and anti-angiogenic stimuli and occurs under both physiological and pathological conditions. Tumor angiogenesis is central for tumor development, and an “angiogenic switch” could be initiated by multiple immune cells, such as neutrophils. Tumor-associated neutrophils promote tumor angiogenesis by the release of both conventional and non-conventional pro-angiogenic factors. Therefore, neutrophil-mediated tumor angiogenesis should be taken into consideration in the design of novel anti-cancer therapy. This review recapitulates the complex role of neutrophils in tumor angiogenesis and summarizes neutrophil-derived pro-angiogenic factors and mechanisms regulating angiogenic activity of tumor-associated neutrophils. Moreover, it provides up-to-date information about neutrophil-targeting therapy, complementary to anti-angiogenic treatment.

Effects of osteogenic ambulatory mechanical stimulation on early stages of BMP-2 mediated bone repair

Purpose: Mechanical loading of bone defects through rehabilitation is a promising approach to stimulate repair and reduce nonunion risk; however, little is known about how therapeutic mechanical stimuli modulate early-stage repair before mineralized bone formation. The objective of this study was to investigate the early effects of osteogenic loading on cytokine expression and angiogenesis during the first 3 weeks of BMP-2 mediated segmental bone defect repair.Materials and Methods: A rat model of BMP-2 mediated bone defect repair was subjected to an osteogenic mechanical loading protocol using ambulatory rehabilitation and a compliant, load-sharing fixator with an integrated implantable strain sensor. The effect of fixator load-sharing on local tissue strain, angiogenesis, and cytokine expression was evaluated.Results: Using sensor readings for local measurements of boundary conditions, finite element simulations showed strain became amplified in remaining soft tissue regions between 1 and 3 weeks (Week 3: load-sharing: -1.89 ± 0.35% and load-shielded: -1.38 ± 0.35% vs. Week 1: load-sharing: -1.54 ± 0.17%; load-shielded: -0.76 ± 0.06%). Multivariate analysis of cytokine arrays revealed that load-sharing significantly altered expression profiles in the defect tissue at 2 weeks compared to load-shielded defects. Specifically, loading reduced VEGF (p = 0.052) and increased CXCL5 (LIX) levels. Subsequently, vascular volume in loaded defects was reduced relative to load-shielded defects but similar to intact bone at 3 weeks. Endochondral bone repair was also observed histologically in loaded defects at 3 weeks.Conclusions: Together, these results demonstrate that moderate ambulatory strains previously shown to stimulate bone regeneration significantly alter early angiogenic and cytokine signaling and may promote endochondral ossification.

Roles of Macrophages in Atherogenesis

Atherosclerosis is a chronic inflammatory disease that may ultimately lead to local proteolysis, plaque rupture, and thrombotic vascular disease, resulting in myocardial infarction, stroke, and sudden cardiac death. Circulating monocytes are recruited to the arterial wall in response to inflammatory insults and differentiate into macrophages which make a critical contribution to tissue damage, wound healing, and also regression of atherosclerotic lesions. Within plaques, macrophages take up aggregated lipoproteins which have entered the vessel wall to give rise to cholesterol-engorged foam cells. Also, the macrophage phenotype is influenced by various stimuli which affect their polarization, efferocytosis, proliferation, and apoptosis. The heterogeneity of macrophages in lesions has recently been addressed by single-cell sequencing techniques. This article reviews recent advances regarding the roles of macrophages in different stages of disease pathogenesis from initiation to advanced atherosclerosis. Macrophage-based therapies for atherosclerosis management are also described.

Effect of a resin-modified calcium silicate cement on inflammatory cell infiltration and reparative dentin formation after pulpotomy in rat molars

Resin monomers and polymerisation initiators have been shown to be cytotoxic for pulp cells and to disturb odontoblast differentiation. This study aimed to compare the effect of a resin-modified calcium silicate cement (TheraCal LC; TC) and a resin-free calcium silicate cement (ProRoot MTA; PR) on pulpal healing after pulpotomy. Pulpotomy was performed on the maxillary first molars of 8-week-old rats using either PR or TC. After 1, 3, 7, 14 and 28 days, pulpal responses were assessed by micro-computed tomography, haematoxylin-eosin staining and immunostaining against CD68, which is a pan-macrophage marker. The results showed that pulpotomy with TC induced persistent infiltration of inflammatory cells, including CD68-positive macrophages, and delayed the formation of reparative dentin as compared with that with PR, although both materials allowed pulpal healing over the long term. Therefore, resin-modified TC was not as biocompatible nor bioinductive as resin-free PR when applied on the healthy pulp of rat molars.

Amazon rainforest rodents (Proechimys) are resistant to post-stroke epilepsy

There are no clinical interventions to prevent post-injury epilepsy, a common and devastating outcome after brain insults. Epileptogenic events that run from brain injury to epilepsy are poorly understood. Previous studies in our laboratory suggested Proechimys, an exotic Amazonian rodent, as resistant to acquired epilepsy development in post-status epilepticus models. The present comparative study was conducted to assess (1) stroke-related brain responses 24-h and 30 days after cortical photothrombosis and (2) post-stroke epilepsy between Proechimys rodents and Wistar rats, a traditional animal used for laboratory research. Proechimys group showed smaller volume of ischemic infarction and lesser glial activation than Wistar group. In contrast to Wistar rats, post-stroke decreased levels of pro-inflammatory cytokines and increased levels of anti-inflammatory mediators and growth factors were found in Proechimys. Electrophysiological signaling changes assessed by cortical spreading depression, in vitro and in vivo, showed that Wistar's brain is most severely affected by stroke. Chronic electrocorticographic recordings showed that injury did not lead to epilepsy in Proechimys whereas 88% of the Wistar rats developed post-stroke epilepsy. Science gains insights from comparative studies on diverse species. Proechimys rodents proved to be a useful animal model to study antiepileptogenic mechanisms after brain insults and complement conventional animal models.

Macrophage Polarization in Response to Biomaterials for Vascularization

Vascularization of tissue engineering constructs is an urgent need for delivering oxygen and nutrients and promoting tissue remodeling. As we all know, almost all implanted biomaterials elicit immune responses. Interestingly, the immunomodulatory biomaterials can utilize the inherent regenerative capability of endogenous cells and stem cells recruited by the activated immune cells to facilitate anagenesis and tissue remodeling. Macrophages, as almost ones of the first responses upon the implantation of biomaterials, play a vital role in guiding vascular formation and tissue remodeling. The polarization of macrophages can be influenced by the physical and chemical properties of biomaterials and thus they display diverse function states. Here, this review focus on the macrophage polarization in response to biomaterials and the interactions between them. It also summarizes the current strategies to promote vascularization of tissue engineering constructs through macrophage responses.

New Angiogenic Regulators Produced by TAMs: Perspective for Targeting Tumor Angiogenesis

Simple Summary

Since the targeting of a single pro-angiogenic factor fails to improve oncological disease outcome, significant efforts have been made to identify new pro-angiogenic factors that could compensate for the deficiency of current therapy or act independently as single drugs. Our review aims to present the state-of-the art for well-known and recently described factors produced by macrophages that induce and regulate angiogenesis. A number of positive and negative regulators of angiogenesis in the tumor microenvironment are produced by tumor-associated macrophages (TAMs). Accumulating evidence has indicated that, apart from the well-known angiogenic factors, there are plenty of novel angiogenesis-regulating proteins that belong to different classes. We summarize the data regarding the direct or indirect mechanisms of the interaction of these factors with endothelial cells during angiogenesis. We highlight the recent findings that explain the limitations in the efficiency of current anti-angiogenic therapy approaches.

Abstract

Angiogenesis is crucial to the supply of a growing tumor with nutrition and oxygen. Inhibition of angiogenesis is one of the main treatment strategies for colorectal, lung, breast, renal, and other solid cancers. However, currently applied drugs that target VEGF or receptor tyrosine kinases have limited efficiency, which raises a question concerning the mechanism of patient resistance to the already developed drugs. Tumor-associated macrophages (TAMs) were identified in the animal tumor models as a key inducer of the angiogenic switch. TAMs represent a potent source not only for VEGF, but also for a number of other pro-angiogenic factors. Our review provides information about the activity of secreted regulators of angiogenesis produced by TAMs. They include members of SEMA and S100A families, chitinase-like proteins, osteopontin, and SPARC. The COX-2, Tie2, and other factors that control the pro-angiogenic activity of TAMs are also discussed. We highlight how these recent findings explain the limitations in the efficiency of current anti-angiogenic therapy. Additionally, we describe genetic and posttranscriptional mechanisms that control the expression of factors regulating angiogenesis. Finally, we present prospects for the complex targeting of the pro-angiogenic activity of TAMs.

Macrophages with reduced expressions of classical M1 and M2 surface markers in human bronchoalveolar lavage fluid exhibit pro-inflammatory gene signatures

The classical M1/M2 polarity of macrophages may not be applicable to inflammatory lung diseases including chronic obstructive pulmonary disease (COPD) due to the complex microenvironment in lungs and the plasticity of macrophages. We examined macrophage sub-phenotypes in bronchoalveolar lavage (BAL) fluid in 25 participants with CD40 (a M1 marker) and CD163 (a M2 marker). Of these, we performed RNA-sequencing on each subtype in 10 patients using the Illumina NextSeq 500. Approximately 25% of the macrophages did not harbor classical M1 or M2 surface markers (double negative, DN), and these cells were significantly enriched in COPD patients compared with non-COPD patients (46.7% vs. 14.5%, p < 0.001). 1886 genes were differentially expressed in the DN subtype compared with  all other subtypes at a 10% false discovery rate. The 602 up-regulated genes included 15 mitochondrial genes and were enriched in 86 gene ontology (GO) biological processes including inflammatory responses. Modules associated with cellular functions including oxidative phosphorylation were significantly down-regulated in the DN subtype. Macrophages in the human BAL fluid, which were negative for both M1/M2 surface markers, harbored a gene signature that was pro-inflammatory and suggested dysfunction in cellular homeostasis. These macrophages may contribute to the pathogenesis and manifestations of inflammatory lung diseases such as COPD.

JNK pathway and heat shock response mediate the survival of C26 colon carcinoma bearing mice fed with the mushroom Pleurotus eryngii var. eryngii without affecting tumor growth or cachexia

In the last few years, there has been emerging interest in developing treatments against human diseases using natural bioactive content. Here, the powder of the edible mushroom Pleurotus eryngii var. eryngii was mixed with the normal diet of mice bearing C26 colon carcinoma. Interestingly, it was evidenced by a significant increase in the survival rate of C26 tumor-bearing mice accompanied by a significant increase in Hsp90 and Hsp27 protein levels in the tumors. These data were paralleled by a decrease in Hsp60 levels. The mushroom introduced in the diet induced the inhibition of the transcription of the pro-inflammatory cytokines IL-6 and IL-1 exerting an anti-inflammatory action. The effects of the mushroom were mediated by the activation of c-Jun NH₂-terminal kinases as a result of metabolic stress induced by the micronutrients introduced in the diet. In the tumors of C26 bearing mice fed with Pleurotus eryngii there was also a decreased expression of the mitotic regulator survivin and the anti-apoptotic factor Bcl-xL as well as an increase in the expression levels of Atg7, a protein that drives autophagy. In our hypothesis the interplay of these molecules favored the survival of the mice fed with the mushroom. These data are promising for the introduction of Pleurotus eryngii as a dietary supplement or as an adjuvant in anti-cancer therapy.

Vascular endothelial growth factor-mediated peritoneal neoangiogenesis in peritoneal dialysis

Peritoneal dialysis (PD) is an important renal replacement therapy for patients with end-stage renal diseases, which is limited by peritoneal neoangiogenesis leading to ultrafiltration failure (UFF). Vascular endothelial growth factor (VEGF) and its receptors are key angiogenic factors involved in almost every step of peritoneal neoangiogenesis. Impaired mesothelial cells are the major sources of VEGF in the peritoneum. The expression of VEGF will be up-regulated in specific pathological conditions in PD patients, such as with non-biocompatible peritoneal dialysate, uremia and inflammation, and so on. Other working cells (i.e. vascular endothelial cells, macrophages and adipocytes) can also stimulate the secretion of VEGF. Meanwhile, hypoxia and activation of complement system further aggravate peritoneal injury and contribute to neoangiogenesis. There are several signalling pathways participating in VEGF-mediated peritoneal neoangiogenesis including tumour growth factor-β, Wnt/β-catenin, Notch and interleukin-6/signal transducer and activator of transcription 3. Moreover, VEGF is highly expressed in dialysate effluent of long-term PD patients and is associated with peritoneal transport function, which supports its role in the alteration of peritoneal structure and function. In this review, we systematically summarize the angiogenic effect of VEGF and evaluate it as a potential target for the prevention of peritoneal neoangiogenesis and UFF. Preservation of the peritoneal membrane using targeted therapy of VEGF-mediated peritoneal neoangiogenesis may increase the longevity of the PD modality for those who require life-long dialysis.

Restoration of the healing microenvironment in diabetic wounds with matrix-binding IL-1 receptor antagonist

Chronic wounds are a major clinical problem where wound closure is prevented by pathologic factors, including immune dysregulation. To design efficient immunotherapies, an understanding of the key molecular pathways by which immunity impairs wound healing is needed. Interleukin-1 (IL-1) plays a central role in regulating the immune response to tissue injury through IL-1 receptor (IL-1R1). Generating a knockout mouse model, we demonstrate that the IL-1-IL-1R1 axis delays wound closure in diabetic conditions. We used a protein engineering approach to deliver IL-1 receptor antagonist (IL-1Ra) in a localised and sustained manner through binding extracellular matrix components. We demonstrate that matrix-binding IL-1Ra improves wound healing in diabetic mice by re-establishing a pro-healing microenvironment characterised by lower levels of pro-inflammatory cells, cytokines and senescent fibroblasts, and higher levels of anti-inflammatory cytokines and growth factors. Engineered IL-1Ra has translational potential for chronic wounds and other inflammatory conditions where IL-1R1 signalling should be dampened.

Spatial Distribution of Mast Cells Regulates Asymmetrical Angiogenesis at the Ocular Surface

Mast cells, historically known for their function as effector cells in the induction of allergic diseases, reside in all vascularized tissues of the body, particularly, in proximity to blood and lymphatic vessels. Despite being neighboring sentinel cells to blood vessels, whether the spatial distribution of mast cells regulates the degree of angiogenesis remains to be investigated. Herein, an asymmetrical distribution of mast cells was shown at the murine ocular surface, with the higher number of mast cells distributed along the nasal limbus of the cornea compared with the temporal side. Using a well-characterized murine model of suture-induced corneal neovascularization, insult to the nasal side was shown to result in more extensive angiogenesis compared with that to the temporal side. To directly assess the impact of the spatial distribution of mast cell on angiogenesis, neovascularization was induced in mast cell-deficient mice (cKit^w-sh). Unlike the wild-type (C57BL/6) mice, cKit^w-sh mice did not show disproportionate growth of corneal blood vessels following the temporal and nasal insult. Moreover, cromolyn-mediated pharmacologic blockade of mast cells at the ocular surface attenuated the asymmetrical nasal and temporal neovascularization, suggesting that spatial distribution of mast cells significantly contributes to angiogenic response at the ocular surface.

Induction of scaffold angiogenesis by recipient vasculature precision micropuncture

The success of engineered tissues continues to be limited by time to vascularization and perfusion. Here, we studied the effects of precision injury to a recipient macrovasculature in promoting neovessel formation in an adjacently placed scaffold. Segmental 60 μm diameter micropunctures (MP) were created in the recipient rat femoral artery and vein followed by coverage with a simple collagen scaffold. Scaffolds were harvested at 24, 48, 72, and 96 h post-implantation for detailed analysis. Those placed on top of an MP segment showed an earlier and more robust cellular infiltration, including both endothelial cells (CD31) and macrophages (F4/80), compared to internal non-micropunctured control limbs (p < 0.05). At the 96-hour timepoint, MP scaffolds demonstrated an increase in physiologic perfusion (p < 0.003) and a 2.5-fold increase in capillary network formation (p < 0.001). These were attributed to an overall upsurge in small vessel quantity. Furthermore, MP positioned scaffolds demonstrated significant increases in many modulators of angiogenesis, including VEGFR2 and Tie-2 despite a decrease in HIF-1α at all timepoints. This study highlights a novel microsurgical approach that can be used to rapidly vascularize or inosculate contiguously placed scaffolds and grafts. Thereby, offering an easily translatable route towards the creation of thicker and more clinically relevant engineered tissues.

Trem-2 Promotes Emergence of Restorative Macrophages and Endothelial Cells During Recovery From Hepatic Tissue Damage

Macrophages are pivotal in mounting liver inflammatory and tissue repair responses upon hepatic injury, showing remarkable functional plasticity. The molecular mechanisms determining macrophage transition from inflammatory to restorative phenotypes in the damaged liver remain unclear. Using mouse models of acute (APAP) and chronic (CCl4) drug-induced hepatotoxic injury we show that the immune receptor Trem-2 controls phenotypic shifts of liver macrophages and impacts endothelial cell differentiation during tissue recovery. Trem-2 gene ablation led to a delayed re-population of Kupffer cells correlating with deterred resolution of hepatic damage following acute and chronic injury. During tissue recovery, we found that macrophages transitioning to Kupffer cells expressed high levels of Trem-2. Acquisition of the transition phenotype was associated with a unique transcriptomic profile denoting strong responsiveness to oxidative stress and downmodulation of the pro-inflammatory phenotype, which was not observed in absence of Trem-2. During tissue recovery, lack of Trem-2 favored accumulation of a liver-damage associated endothelial cell population (LDECs), whose transcriptional program was compatible with endothelial de-differentiation. Accordingly, LDECs precursor potential is supported by the downregulation of surface endothelial cell markers and by striking in vitro morphological changes towards typical endothelial cells. In conclusion, we found that the dynamics of liver macrophages in response to liver injury are critically controlled by Trem-2 and this regulation is interlinked with the de-differentiation of endothelial cells and heightened liver pathology. We propose that Trem-2 promotes the transition from pro-inflammatory to tissue repair phase by driving the acquisition of restorative properties in phagocytic macrophages.

Alternative Pathways of IL-1 Activation, and Its Role in Health and Disease

Cytokines activate or inhibit immune cell behavior and are thus integral to all immune responses. IL-1α and IL-1β are powerful apical cytokines that instigate multiple downstream processes to affect both innate and adaptive immunity. Multiple studies show that IL-1β is typically activated in macrophages after inflammasome sensing of infection or danger, leading to caspase-1 processing of IL-1β and its release. However, many alternative mechanisms activate IL-1α and IL-1β in atypical cell types, and IL-1 function is also important for homeostatic processes that maintain a physiological state. This review focuses on the less studied, yet arguably more interesting biology of IL-1. We detail the production by, and effects of IL-1 on specific innate and adaptive immune cells, report how IL-1 is required for barrier function at multiple sites, and discuss how perturbation of IL-1 pathways can drive disease. Thus, although IL-1 is primarily studied for driving inflammation after release from macrophages, it is clear that it has a multifaceted role that extends far beyond this, with various unconventional effects of IL-1 vital for health. However, much is still unknown, and a detailed understanding of cell-type and context-dependent actions of IL-1 is required to truly understand this enigmatic cytokine, and safely deploy therapeutics for the betterment of human health.

Angiogenesis in Lymph Nodes Is a Critical Regulator of Immune Response and Lymphoma Growth

Tumor-induced remodeling of the microenvironment in lymph nodes (LNs) includes the formation of blood vessels, which goes beyond the regulation of metabolism, and shaping a survival niche for tumor cells. In contrast to solid tumors, which primarily rely on neo-angiogenesis, hematopoietic malignancies usually grow within pre-vascularized autochthonous niches in secondary lymphatic organs or the bone marrow. The mechanisms of vascular remodeling in expanding LNs during infection-induced responses have been studied in more detail; in contrast, insights into the conditions of lymphoma growth and lodging remain enigmatic. Based on previous murine studies and clinical trials in human, we conclude that there is not a universal LN-specific angiogenic program applicable. Instead, signaling pathways that are tightly connected to autochthonous and infiltrating cell types contribute variably to LN vascular expansion. Inflammation related angiogenesis within LNs relies on dendritic cell derived pro-inflammatory cytokines stimulating vascular endothelial growth factor-A (VEGF-A) expression in fibroblastic reticular cells, which in turn triggers vessel growth. In high-grade B cell lymphoma, angiogenesis correlates with poor prognosis. Lymphoma cells immigrate and grow in LNs and provide pro-angiogenic growth factors themselves. In contrast to infectious stimuli that impact on LN vasculature, they do not trigger the typical inflammatory and hypoxia-related stroma-remodeling cascade. Blood vessels in LNs are unique in selective recruitment of lymphocytes via high endothelial venules (HEVs). The dissemination routes of neoplastic lymphocytes are usually disease stage dependent. Early seeding via the blood stream requires the expression of the homeostatic chemokine receptor CCR7 and of L-selectin, both cooperate to facilitate transmigration of tumor and also of protective tumor-reactive lymphocytes via HEV structures. In this view, the HEV route is not only relevant for lymphoma cell homing, but also for a continuous immunosurveillance. We envision that HEV functional and structural alterations during lymphomagenesis are not only key to vascular remodeling, but also impact on tumor cell accessibility when targeted by T cell-mediated immunotherapies.

An allosteric interleukin-1 receptor modulator mitigates inflammation and photoreceptor toxicity in a model of retinal degeneration

BACKGROUND

Inflammation and particularly interleukin-1β (IL-1β), a pro-inflammatory cytokine highly secreted by activated immune cells during early AMD pathological events, contribute significantly to retinal neurodegeneration. Here, we identify specific cell types that generate IL-1β and harbor the IL-1 receptor (IL-1R) and pharmacologically validate IL-1β's contribution to neuro-retinal degeneration using the IL-1R allosteric modulator composed of the amino acid sequence rytvela (as well as the orthosteric antagonist, Kineret) in a model of blue light-induced retinal degeneration.

METHODS

Mice were exposed to blue light for 6 h and sacrificed 3 days later. Mice were intraperitoneally injected with rytvela, Kineret, or vehicle twice daily for 3 days. The inflammatory markers F4/80, NLRP3, caspase-1, and IL-1β were assessed in the retinas. Single-cell RNA sequencing was used to determine the cell-specific expression patterns of retinal Il1b and Il1r1. Macrophage-induced photoreceptor death was assessed ex vivo using retinal explants co-cultured with LPS-activated bone marrow-derived macrophages. Photoreceptor cell death was evaluated by the TUNEL assay. Retinal function was assessed by flash electroretinography.

RESULTS

Blue light markedly increased the mononuclear phagocyte recruitment and levels of inflammatory markers associated with photoreceptor death. Co-localization of NLRP3, caspase-1, and IL-1β with F4/80⁺ mononuclear phagocytes was clearly detected in the subretinal space, suggesting that these inflammatory cells are the main source of IL-1β. Single-cell RNA sequencing confirmed the immune-specific expression of Il1b and notably perivascular macrophages in light-challenged mice, while Il1r1 expression was found primarily in astrocytes, bipolar, and vascular cells. Retinal explants co-cultured with LPS/ATP-activated bone marrow-derived macrophages displayed a high number of TUNEL-positive photoreceptors, which was abrogated by rytvela treatment. IL-1R antagonism significantly mitigated the inflammatory response triggered in vivo by blue light exposure, and rytvela was superior to Kineret in preserving photoreceptor density and retinal function.

CONCLUSION

These findings substantiate the importance of IL-1β in neuro-retinal degeneration and revealed specific sources of Il1b from perivascular MPs, with its receptor Ilr1 being separately expressed on surrounding neuro-vascular and astroglial cells. They also validate the efficacy of rytvela-induced IL-1R modulation in suppressing detrimental inflammatory responses and preserving photoreceptor density and function in these conditions, reinforcing the rationale for clinical translation.

Inflammasomes: a preclinical assessment of targeting in atherosclerosis

INTRODUCTION

Inflammasomes are central to atherosclerotic vascular dysfunction with regulatory effects on inflammation, immune modulation, and lipid metabolism. The NLRP3 inflammasome is a critical catalyst for atherogenesis thus highlighting its importance in understanding the pathophysiology of atherosclerosis and for the identification of novel therapeutic targets and biomarkers for the treatment of cardiovascular disease.

AREAS COVERED

This review includes an overview of macrophage lipid metabolism and the role of NLRP3 inflammasome activity in cardiovascular inflammation and atherosclerosis. We highlight key activators, signal transducers and major regulatory components that are being considered as putative therapeutic targets for inhibition of NLRP3-mediated cardiovascular inflammation and atherosclerosis.

EXPERT OPINION

NLRP3 inflammasome activity lies at the nexus between inflammation and cholesterol metabolism; it offers unique opportunities for understanding atherosclerotic pathophysiology and identifying novel modes of treatment. As such, a host of NLRP3 signaling cascade components have been identified as putative targets for drug development. We catalog these current discoveries in therapeutic targeting of the NLRP3 inflammasome and, utilizing the CANTOS trial as the translational (bench-to-bedside) archetype, we examine the complexities, challenges, and ultimate goals facing the field of atherosclerosis research.

CDllb+ targeted depletion of macrophages negatively affects bone fracture healing

Inflammation is an important part of the fracture repair process which requires osteogenic cells to interact with innate immune cells such as macrophages. All murine macrophages express the F4/80 cell surface marker but they may be further subdivided into two main phenotypes: M1 (proinflammatory) or M2 (anti-inflammatory) based on surface marker expression and function. Macrophages polarize between these two main classes in response to inflammation while differentially regulating the healing process. Studies have shown that F4/80+ cell ablation impairs fracture healing, however, the distinct phenotypes that participate in the early healing process is unclear. We hypothesized that the M1 subtype is essential for the early steps of fracture healing and their depletion would impair fracture repair. To test this hypothesis, M1 (F4/80+/MHCII+/CD86+/CDllb+) macrophages were depleted using a saporin conjugated Mac-1 antibody (Mac1SAP) in vitro using primary macrophages and in vivo using a mouse femur fracture model. Primary macrophages isolated from mice femoral bone marrow were either left undifferentiated (+PBS), differentiated into M1 macrophages (+LPS), or differentiated to M2 macrophages (+IL-4), and then treated with either vehicle or 10 pM Mac1SAP. Samples were collected at day 2 and 5 post Mac1SAP treatment. Macrophage subtypes were identified by flow cytometry and cytokine secretion profiles were quantified using xMAP. For the in vivo model, mice were treated with Mac1SAP 24 h prior to fracture. Femur bone marrow samples were collected and analyzed by flow cytometry, xMAP, immunohistochemistry, MicroCT, and histology. The results demonstrated that Mac1SAP significantly depleted M1 macrophages both in vivo and in vitro. Mac1SAP treatment altered expression of 75% of cytokines in vitro and 30% of cytokines in vivo including IL-6, TNF-a, and IP-10. In both the in vitro and in vivo models, the M1 subtype correlated highly with cytokines G-CSF, IL-1α, IL-6, IL-10, LIX, KC, MCP-1, IP-10, MIP1α, MIP1β, RANTES, IL-9, IL-2 and TNFα. M1 depletion was also found to reduced callus properties at day 14 via microCT analysis. Overall, the data suggests that depletion of M1 macrophages by Mac1SAP treatment alters the cytokine expression profiles during early bone repair which ultimately impairs bone healing.

Macrophage subtype and cytokine expression characterization during the acute inflammatory phase of mouse bone fracture repair

Fracture repair is a complex process requiring heterotypic interactions between osteogenic cells and immune cells. Recent evidence indicates that macrophages are critically involved in fracture repair. Polarized macrophage populations differentially promote and regulate inflammation in other tissues, but little is known about the various macrophage subtypes and their signaling activities following a bone fracture. The authors hypothesized that classically activated (M1 subtype) and alternatively activated (M2 subtype) macrophages are active during the early repair process to initiate and regulate the inflammatory response. To test our hypothesis, bone marrow was collected from intact femurs (naïve group), contralateral and fractured femurs of mice on days 0, 1, 2, 4, and 7 postfracture. Macrophages were isolated from the bone marrow and macrophage subtypes were identified using flow cytometry with antibodies to F4/80, MHC II, CD86, CD11c, and CD40. Bone marrow cytokine levels were measured using xMAP. Flow cytometry revealed dynamic changes in M1 subtype (F4/80+/MHC II+/CD86+), M2 subtype (F4/80+/MHC II-/CD86-), and dendritic cell (DCs; MHCII+/CD11c+/CD40+) populations following fracture as compared to naïve controls. M1 subtype levels were correlated with IL-1α, IL-1ß, IL-2, IL-17, Eotaxin, and MCP-1, while DCs were correlated with IL-6, G-CSF, LIF, KC, and VEGF-A. The results indicate that M1 and M2 subtypes and DCs are recruited to the fracture site early during the repair process and consequently may work in tandem to regulate the inflammatory response required to recruit osteogenic cells needed for later stages of repair.

Interleukin-1β and Cancer

Within a tumor, IL-1β is produced and secreted by various cell types, such as immune cells, fibroblasts, or cancer cells. The IL1B gene is induced after "priming" of the cells and a second signal is required to allow IL-1β maturation by inflammasome-activated caspase-1. IL-1β is then released and leads to transcription of target genes through its ligation with IL-1R1 on target cells. IL-1β expression and maturation are guided by gene polymorphisms and by the cellular context. In cancer, IL-1β has pleiotropic effects on immune cells, angiogenesis, cancer cell proliferation, migration, and metastasis. Moreover, anti-cancer treatments are able to promote IL-1β production by cancer or immune cells, with opposite effects on cancer progression. This raises the question of whether or not to use IL-1β inhibitors in cancer treatment.

Carbon Nanomaterials Promote M1/M2 Macrophage Activation

Toxic effects of certain carbon nanomaterials (CNM) have been observed in several exposure scenarios both in vivo and in vitro. However, most of the data currently available has been generated in a high-dose/acute exposure setup, limiting the understanding of their immunomodulatory mechanisms. Here, macrophage-like THP-1 cells, exposed to ten different CNM for 48 h in low-cytotoxic concentration of 10 µg mL^-1 , are characterized by secretion of different cytokines and global transcriptional changes. Subsequently, the relationships between cytokine secretion and transcriptional patterns are modeled, highlighting specific pathways related to alternative macrophage activation. Finally, time- and dose-dependent activation of transcription and secretion of M1 marker genes IL-1β and tumor necrosis factor, and M2 marker genes IL-10 and CSF1 is confirmed among the three most responsive CNM, with concentrations of 5, 10, and 20 µg mL^-1 at 24, 48, and 72 h of exposure. These results underline CNM effects on the formation of cell microenvironment and gene expression leading to specific patterns of macrophage polarization. Taken together, these findings imply that, instead of a high and toxic CNM dose, a sub-lethal dose in controlled exposure setup can be utilized to alter the cell microenvironment and program antigen presenting cells, with fascinating implications for novel therapeutic strategies.

Macrophages potentiate STAT3 signaling in skeletal muscles and regulate pancreatic cancer cachexia

Incidence of cachexia is highly prevalent in pancreatic ductal adenocarcinoma (PDAC); advanced disease stage directly correlates with decreased muscle and fat mass in PDAC patients. The pancreatic tumor microenvironment is central to the release of systemic factors that govern lipolysis, proteolysis, and muscle and fat degeneration leading to the cachectic phenotype in cancer patients. The current study explores the role of macrophages, a key immunosuppressive player in the pancreatic tumor microenvironment, in regulating cancer cachexia. We observed a negative correlation between CD163-positive macrophage infiltration and muscle-fiber cross sectional area in human PDAC patients. To investigate the role of macrophages in myodegeneration, we utilized conditioned media transplant assays and orthotopic models of PDAC-induced cachexia in immune-competent mice with and without macrophage depletion. We observed that macrophage-derived conditioned medium, in combination with tumor cell-conditioned medium, promoted muscle atrophy through STAT3 signaling. Furthermore, macrophage depletion attenuated systemic inflammation and muscle wasting in pancreatic tumor-bearing mice. Targeting macrophage-mediated STAT3 activation or macrophage-derived interleukin-1 alpha or interleukin-6 diminished myofiber atrophy. Taken together, the current study identified the critical association between macrophages and cachexia phenotype in pancreatic cancer.

Cytokines in Inflammatory Disease

This review aims to briefly discuss a short list of a broad variety of inflammatory cytokines. Numerous studies have implicated that inflammatory cytokines exert important effects with regard to various inflammatory diseases, yet the reports on their specific roles are not always consistent. They can be used as biomarkers to indicate or monitor disease or its progress, and also may serve as clinically applicable parameters for therapies. Yet, their precise role is not always clearly defined. Thus, in this review, we focus on the existing literature dealing with the biology of cytokines interleukin (IL)-6, IL-1, IL-33, tumor necrosis factor-alpha (TNF-α), IL-10, and IL-8. We will briefly focus on the correlations and role of these inflammatory mediators in the genesis of inflammatory impacts (e.g., shock, trauma, immune dysregulation, osteoporosis, and/or critical illness).

Mechanism of angiogenesis promotion with Shexiang Baoxin Pills by regulating function and signaling pathway of endothelial cells through macrophages

BACKGROUND AND AIMS

"Shexiang Baoxin Pill" (SBP), a commonly used traditional Chinese medicine, has been used to treat angina, myocardial infarction and coronary heart disease in China for thirty years. SBP has been proven to promote angiogenesis in a rat model of myocardial infarction (MI). The aim of the present study was to determine the pro-angiogenic effects and mechanism of SBP during inflammation or ischemic pathological conditions and elucidate its regulatory effects on endothelial cell function and signaling pathways mediated by macrophages.

METHODS

We used a polyvinyl alcohol (PVA) sponge implantation mouse model as an inflammatory angiogenesis model and utilized a mouse femoral artery ligation model as a hind limb ischemia model. We also performed cell proliferation, cell migration and tubule formation in vitro experiments to assess the effects of SBP on endothelial cell function and signaling pathways by stimulating macrophage activity.

RESULTS

The in vitro experiment results showed that SBP could significantly increase the expression of mRNAs and proteins associated with angiogenesis in endothelial cells by activating macrophages to release pro-angiogenic factors such as Vegf-a. Activation of macrophages by SBP eventually led to endothelial cell proliferation, migration and tubule formation and increased the expression of p-Akt and p-Erk1/2 proteins in the downstream PI3K/Akt and MAPK/Erk1/2 signaling pathways related to angiogenesis, respectively. The in vivo experiment results indicated that SBP had angiogenesis effects in both inflammatory and ischemic angiogenesis models with dose- and time-dependent effects.

CONCLUSION

Shexiang Baoxin Pills can promote angiogenesis by activating macrophages to regulate endothelial cell function and signal transduction pathways.

Inhibition of NLRP3 inflammasome in tumor microenvironment leads to suppression of metastatic potential of cancer cells

Tumor microenvironment favors tumor cells to promote their growth and metastasis such as migration, invasion, and angiogenesis. IL-1β, one of the inflammatory cytokines released from myeloid cells in tumor microenvironment, plays an important role in development and progress of tumor. The activation of inflammasome is a critical step to secrete mature IL-1β through stepwise reactions to activate capspase-1. Therefore, we investigated whether the inhibition of NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome in macrophages regulated the metastatic potential of tumor cells. NLRP3 inflammasome was activated by ATP in bone marrow-derived primary mouse macrophages. The metastatic potential of mouse melanoma cell line (B16F10) was determined by migration and invasion assays with transwell system. ATP-treated wild-type macrophages increased the migration and invasion of melanoma cells. However, NLRP3- or caspase-1-knockout macrophages exhibited greatly diminished ability to promote the migration and invasion of melanoma cells. In addition, treatment with celastrol, an inhibitor of NLRP3 inflammasome, reduced the potency of macrophages to stimulate migration and invasion of melanoma cells. The results demonstrate that inhibition of the NLRP3 inflammasome in macrophages by genetic deficiency or a pharmacological inhibitor is linked to suppression of the metastatic potential of tumor cells. The results would provide a novel anti-cancer strategy to modulate tumor microenvironment by suppressing NLRP3 inflammasome and consequently reducing IL-1β production.

IL-1 Family Cytokine Regulation of Vascular Permeability and Angiogenesis

The IL-1 family of cytokines are well-known for their primary role in initiating inflammatory responses both in response to and acting as danger signals. It has long been established that IL-1 is capable of simultaneously regulating inflammation and angiogenesis, indeed one of IL-1's earliest names was haemopoeitn-1 due to its pro-angiogenic effects. Other IL-1 family cytokines are also known to have roles in mediating angiogenesis, either directly or indirectly via induction of proangiogenic factors such as VEGF. Of note, some of these family members appear to have directly opposing effects in different tissues and pathologies. Here we will review what is known about how the various IL-1 family members regulate vascular permeability and angiogenic function in a range of different tissues, and describe some of the mechanisms employed to achieve these effects.

The emerging roles of inflammasome-dependent cytokines in cancer development

In addition to the genomic alterations that occur in malignant cells, the immune system is increasingly appreciated as a critical axis that regulates the rise of neoplasms and the development of primary tumours and metastases. The interaction between inflammatory cell infiltrates and stromal cells in the tumour microenvironment is complex, with inflammation playing both pro- and anti-tumorigenic roles. Inflammasomes are intracellular multi-protein complexes that act as key signalling hubs of the innate immune system. They respond to cellular stress and trauma by promoting activation of caspase-1, a protease that induces a pro-inflammatory cell death mode termed pyroptosis along with the maturation and secretion of the pro-inflammatory cytokines interleukin (IL)-1β and IL-18. Here, we will briefly introduce inflammasome biology with a focus on the dual roles of inflammasome-produced cytokines in cancer development. Despite emerging insight that inflammasomes may promote and suppress cancer development according to the tumour stage and the tumour microenvironment, much remains to be uncovered. Further exploration of inflammasome biology in tumorigenesis should enable the development of novel immunotherapies for cancer patients.

VEGF-like protein from Apostichopus japonicus promotes cell proliferation and migration

Vascular endothelial growth factor (VEGF) is a key conservative regulator of inflammation response by promoting cell proliferation, migration, and vascular permeability. It also induces the release of inflammatory factors in vertebrates. We previously characterized NLR family pyrin domain containing 3 and HMGB3 homology in Apostichopus japonicus, providing the occurrence of inflammation in this species. However, to our knowledge, other inflammation-related molecules, such as VEGF, have rarely been investigated. In the present study, a novel VEGF homolog was identified from A. japonicus (designated as AjVEGF) by rapid amplification of cDNA ends. Full-length cDNA of AjVEGF was 3181 bp with a putative open reading frame of 1752 bp encoding 583 amino acid (aa) residue protein. Structural analysis revealed that AjVEGF processed characteristic VEGF domains of platelet-derived growth factor domain (132-232 aa) and CXC domain (223-270 aa). Multiple sequence alignment and phylogenetic analysis both supported that AjVEGF belongs to a new member of VEGF protein subfamily. Both Vibrio splendidus challenge in vivo and lipopolysaccharide stimulation in vitro could significantly upregulate mRNA expression of AjVEGF compared with the control group. Functional analysis indicated that recombinant AjVEGF promoted coelomocyte proliferation and migration not only in sea cucumber but also in human colorectal adenocarcinoma cells (HT29). This consistent function was also detected for human VEGFs. Taken together, these findings suggest that AjVEGF has a similar function of VEGF in higher animals and might serve as a candidate cytokine in sea cucumber inflammation.