IL-25 induces airways angiogenesis and expression of multiple angiogenic factors in a murine asthma model

Airway remodelling in asthma and the epithelium: on the edge of a new era

Asthma is a chronic, heterogeneous disease of the airways, often characterised by structural changes known collectively as airway remodelling. In response to environmental insults, including pathogens, allergens and pollutants, the epithelium can initiate remodelling via an inflammatory cascade involving a variety of mediators that have downstream effects on both structural and immune cells. These mediators include the epithelial cytokines thymic stromal lymphopoietin, interleukin (IL)-33 and IL-25, which facilitate airway remodelling through cross-talk between epithelial cells and fibroblasts, and between mast cells and airway smooth muscle cells, as well as through signalling with immune cells such as macrophages. The epithelium can also initiate airway remodelling independently of inflammation in response to the mechanical stress present during bronchoconstriction. Furthermore, genetic and epigenetic alterations to epithelial components are believed to influence remodelling. Here, we review recent advances in our understanding of the roles of the epithelium and epithelial cytokines in driving airway remodelling, facilitated by developments in genetic sequencing and imaging techniques. We also explore how new and existing therapeutics that target the epithelium and epithelial cytokines could modify airway remodelling.

Impact of obesity on airway remodeling in asthma: pathophysiological insights and clinical implications

The prevalence of obesity among asthma patients has surged in recent years, posing a significant risk factor for uncontrolled asthma. Beyond its impact on asthma severity and patients' quality of life, obesity is associated with reduced lung function, increased asthma exacerbations, hospitalizations, heightened airway hyperresponsiveness, and elevated asthma-related mortality. Obesity may lead to metabolic dysfunction and immune dysregulation, fostering chronic inflammation characterized by increased pro-inflammatory mediators and adipocytokines, elevated reactive oxygen species, and reduced antioxidant activity. This chronic inflammation holds the potential to induce airway remodeling in individuals with asthma and obesity. Airway remodeling encompasses structural and pathological changes, involving alterations in the airway's epithelial and subepithelial layers, hyperplasia and hypertrophy of airway smooth muscle, and changes in airway vascularity. In individuals with asthma and obesity, airway remodeling may underlie heightened airway hyperresponsiveness and increased asthma severity, ultimately contributing to the development of persistent airflow limitation, declining lung function, and a potential increase in asthma-related mortality. Despite efforts to address the impact of obesity on asthma outcomes, the intricate mechanisms linking obesity to asthma pathophysiology, particularly concerning airway remodeling, remain incompletely understood. This comprehensive review discusses current research investigating the influence of obesity on airway remodeling, to enhance our understanding of obesity's role in the context of asthma airway remodeling.

Amphiregulin Exerts Proangiogenic Effects in Developing Murine Lungs

Interrupted lung angiogenesis is a hallmark of bronchopulmonary dysplasia (BPD); however, druggable targets that can rescue this phenotype remain elusive. Thus, our investigation focused on amphiregulin (Areg), a growth factor that mediates cellular proliferation, differentiation, migration, survival, and repair. While Areg promotes lung branching morphogenesis, its effect on endothelial cell (EC) homeostasis in developing lungs is understudied. Therefore, we hypothesized that Areg promotes the proangiogenic ability of the ECs in developing murine lungs exposed to hyperoxia. Lung tissues were harvested from neonatal mice exposed to normoxia or hyperoxia to determine Areg expression. Next, we performed genetic loss-of-function and pharmacological gain-of-function studies in normoxia- and hyperoxia-exposed fetal murine lung ECs. Hyperoxia increased Areg mRNA levels and Areg+ cells in whole lungs. While Areg expression was increased in lung ECs exposed to hyperoxia, the expression of its signaling receptor, epidermal growth factor receptor, was decreased, indicating that hyperoxia reduces Areg signaling in lung ECs. Areg deficiency potentiated hyperoxia-mediated anti-angiogenic effects. In contrast, Areg treatment increased extracellular signal-regulated kinase activation and exerted proangiogenic effects. In conclusion, Areg promotes EC tubule formation in developing murine lungs exposed to hyperoxia.

IL-25 induces airway remodeling in asthma by orchestrating the phenotypic changes of epithelial cell and fibrocyte

BACKGROUND

Previous studies have shown that IL-25 levels are increased in patients with asthma with fixed airflow limitation (FAL). However, the mechanism by which IL-25 contributes to airway remodeling and FAL remains unclear. Here, we hypothesized that IL-25 facilitates pro-fibrotic phenotypic changes in bronchial epithelial cells (BECs) and circulating fibrocytes (CFs), orchestrates pathological crosstalk from BECs to CFs, and thereby contributes to airway remodeling and FAL.

METHODS

Fibrocytes from asthmatic patients with FAL and chronic asthma murine models were detected using flow cytometry, multiplex staining and multispectral imaging analysis. The effect of IL-25 on BECs and CFs and on the crosstalk between BECs and CFs was determined using cell culture and co-culture systems.

RESULTS

We found that asthmatic patients with FAL had higher numbers of IL-25 receptor (i.e., IL-17RB)+-CFs, which were negatively correlated with forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC). The number of airway IL-17RB+-fibrocytes was significantly increased in ovalbumin (OVA)- and IL-25-induced asthmatic mice versus the control subjects. BECs stimulated with IL-25 exhibited an epithelial-mesenchymal transition (EMT)-like phenotypic changes. CFs stimulated with IL-25 produced high levels of extracellular matrix (ECM) proteins and connective tissue growth factors (CTGF). These profibrotic effects of IL-25 were partially blocked by the PI3K-AKT inhibitor LY294002. In the cell co-culture system, OVA-challenged BECs facilitated the migration and expression of ECM proteins and CTGF in CFs, which were markedly blocked using an anti-IL-17RB antibody.

CONCLUSION

These results suggest that IL-25 may serve as a potential therapeutic target for asthmatic patients with FAL.

Type 1 and type 2 cytokine-mediated immune orchestration in the tumour microenvironment and their therapeutic potential

Cancer remains the second leading cause of death worldwide despite modern breakthroughs in medicine, and novel treatments are urgently needed. The revolutionary success of immune checkpoint inhibitors in the past decade serves as proof of concept that the immune system can be effectively harnessed to treat cancer. Cytokines are small signalling proteins with critical roles in orchestrating the immune response and have become an attractive target for immunotherapy. Type 1 immune cytokines, including interferon γ (IFNγ), interleukin-12 (IL-12), and tumour necrosis factor α (TNFα), have been shown to have largely tumour suppressive roles in part through orchestrating anti-tumour immune responses mediated by natural killer (NK) cells, CD8⁺ T cells and T helper 1 (Th1) cells. Conversely, type 2 immunity involving group 2 innate lymphoid cells (ILC2s) and Th2 cells are involved in tissue regeneration and wound repair and are traditionally thought to have pro-tumoural effects. However, it is found that the classical type 2 immune cytokines IL-4, IL-5, IL-9, and IL-13 may have conflicting roles in cancer. Similarly, type 2 immunity-related cytokines IL-25 and IL-33 with recently characterised roles in cancer may either promote or suppress tumorigenesis in a context-dependent manner. Furthermore, type 1 cytokines IFNγ and TNFα have also been found to have pro-tumoural effects under certain circumstances, further complicating the overall picture. Therefore, the dichotomy of type 1 and type 2 cytokines inhibiting and promoting tumours respectively is not concrete, and attempts of utilising these for cancer immunotherapy must take into account all available evidence. This review provides an overview summarising the current understanding of type 1 and type 2 cytokines in tumour immunity and discusses the prospects of harnessing these for immunotherapy in light of previous and ongoing clinical trials.

Emerging roles for IL-25 and IL-33 in colorectal cancer tumorigenesis

Colorectal cancer (CRC) is the second leading cause of cancer-related death worldwide, and is largely refractory to current immunotherapeutic interventions. The lack of efficacy of existing cancer immunotherapies in CRC reflects the complex nature of the unique intestinal immune environment, which serves to maintain barrier integrity against pathogens and harmful environmental stimuli while sustaining host-microbe symbiosis during homeostasis. With their expression by barrier epithelial cells, the cytokines interleukin-25 (IL-25) and IL-33 play key roles in intestinal immune responses, and have been associated with inappropriate allergic reactions, autoimmune diseases and cancer pathology. Studies in the past decade have begun to uncover the important roles of IL-25 and IL-33 in shaping the CRC tumour immune microenvironment, where they may promote or inhibit tumorigenesis depending on the specific CRC subtype. Notably, both IL-25 and IL-33 have been shown to act on group 2 innate lymphoid cells (ILC2s), but can also stimulate an array of other innate and adaptive immune cell types. Though sometimes their functions can overlap they can also produce distinct phenotypes dependent on the differential distribution of their receptor expression. Furthermore, both IL-25 and IL-33 modulate pathways previously known to contribute to CRC tumorigenesis, including angiogenesis, tumour stemness, invasion and metastasis. Here, we review our current understanding of IL-25 and IL-33 in CRC tumorigenesis, with specific focus on dissecting their individual function in the context of distinct subtypes of CRC, and the potential prospects for targeting these pathways in CRC immunotherapy.

Interleukin-25-Mediated-IL-17RB Upregulation Promotes Cutaneous Wound Healing in Diabetic Mice by Improving Endothelial Cell Functions

Diabetic foot ulcer (DFU) frequently leads to non-traumatic amputation and finally even death. However, the mechanism of DFU is not fully understood. Interleukin 25 (IL-25), an alarmin cytokine that responds to tissue injury, has been reported to participate in tissue regeneration and maintaining glucose homeostasis. However, the role of IL-25 in diabetic wound healing remains unknown. Here, we showed that interleukin 17 receptor B (IL-17RB), the functional receptor of IL-25, was significantly inhibited in the wound skin of both diabetic patients with DFU and streptozotocin (STZ)-induced diabetic mice. Topical administration of recombinant IL-25 protein improved angiogenesis and collagen deposition in the wound bed and thus ameliorated delayed diabetic wound healing. IL-25 increased endothelial-specific CD31 expression in diabetic wounds and exogenous IL-25 protected endothelial cells from high glucose-impaired cell migration and tube formation in vitro. We further revealed that IL-25-mediated-IL-17RB signaling rescued the downregulation of Wnt/β-catenin pathway both in vivo in diabetic mice and in vitro in HUVECs and induced the phosphorylation of AKT and ERK 1/2 in HUVECs under high glucose conditions. This study defines a positive regulatory role of IL-25-mediated-IL-17RB signaling in diabetic wound healing and suggests that induction of IL-25-mediated-IL-17RB signaling may be a novel therapeutic strategy for treating poor healing diabetic wounds.

Ncf1 Governs Immune Niches in the Lung to Mediate Pulmonary Inflammation in Mice

Neutrophil cytosolic factor 1 (Ncf1) is a major genetic factor associated with autoimmune diseases and has been identified as a key player in autoimmune mediated inflammation. We addressed the role of Ncf1 in an antigen-induced pulmonary inflammation model, and found that the Ncf1^m1j mutation, causing a deficient reactive oxygen species response, alleviated disease. The Ncf1^m1j mutation was associated with a reduced inflammatory cell infiltration in airways, but had limited effect on mucus secretion, antibody production and lung fibrosis. The disease remission in the Ncf1 mutated mice was reversed when functional Ncf1 was transgenically expressed in alveolar macrophages, suggesting that the cellular inflammation was depended on functional Ncf1 in alveolar macrophages. By determining cytokine and chemokine profiles in lung and serum, we found that Ncf1 deficiency allowed an increased expression of Th1 cytokines, including TNF-α, IFN-γ and IL-12. Since also epithelial cytokines were found to be regulated by Ncf1, we tested the effect of Ncf1 in IL-33 and IL-25 induced lung inflammation models. Mice with the Ncf1^m1j mutation showed less sensitivity to IL-33, but not IL-25, induced lung inflammation, in a macrophage independent manner. The mice with deficient Ncf1 showed a reduced eosinophil infiltration and group 2 innate lymphoid cell (ILC2) activation. The production of IFN-γ in CD4⁺ T cells was increased, whereas IL-5 and IL-13 in ILC2 were decreased. Importantly, anti-IFN-γ antibody treatment of Ncf1 deficient mice increased eosinophil infiltration and rescued ILC2 activation in the lung. We conclude that Ncf1 deficiency enhances Th1 response, deactivates ILC2, and protects against pulmonitis.

The Identification of Childhood Asthma Progression-Related lncRNAs and mRNAs Suitable as Biomarkers Using Weighted Gene Coexpression Network Analysis

Background

Asthma is a common chronic respiratory disease in children, seriously affecting children's health and growth. This bioinformatics study aimed to identify potential RNA candidates closely associated with childhood asthma development within current gene databases.

Methods

GSE65204 and GSE19187 datasets were screened and downloaded from the NCBI GEO database. Differentially expressed long noncoding RNAs (DE-lncRNAs) and mRNAs (DE-mRNAs) were identified using the Bioconductor limma package in R, and these DE-mRNAs were used to perform biological process (BP) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Thereafter, weighted gene coexpression network analysis (WGCNA) was utilized to screen the modules directly related to childhood asthma, and a coexpression network of DE-lncRNAs and DE-mRNAs was built. Finally, principal component analysis (PCA) was performed.

Results

In total, 7 DE-lncRNAs and 1060 DE-mRNAs, as well as 7 DE-lncRNAs and 1027 DE-mRNAs, were identified in GSE65204 and GSE19187, respectively. After comparison, 336 overlapping genes had the same trend of expression, including 2 overlapped DE-lncRNAs and 334 overlapped DE-mRNAs. These overlapped DE-mRNAs were enriched in 28 BP and 12 KEGG pathways. Eleven modules were obtained in GSE65204, and it was found that the purple, black, and yellow modules were significantly positively correlated with asthma development. Subsequently, a coexpression network including 63 DE-mRNAs and 2 DE-lncRNAs was built, and five KEGG pathways, containing 8 genes, were found to be directly associated with childhood asthma. The PCA further verified these results.

Conclusion

LncRNAs LINC01559 and SNHG8 and mRNAs VWF, LAMB3, LAMA4, CAV1, ALDH1A3, SMOX, GNG4, and PPARG were identified as biomarkers associated with the progression of childhood asthma.

Calcilytics: a non-steroidal replacement for inhaled steroid and SABA/LABA therapy of human asthma?

INTRODUCTION

Asthma afflicts more than 300 million people. Contemporary mainstay therapies (inhaled corticosteroids and bronchodilators), prescribed empirically, control symptoms resulting from airways obstruction tolerably well in many patients but it is less clear that they alter the natural history of progressive airways inflammation and remodeling resulting in severe, therapy-resistant obstruction in a significant minority (5-10%), causing lifelong symptoms and elevated risk of recurrent hospital admission and death. Furthermore, no current anti-asthma drug targets bronchial smooth muscle hyperresponsiveness, a critical contributor to airways obstruction and the fundamental physiological abnormality characterizing asthma. Recent monoclonal antibody (biological) therapies reduce obstruction and exacerbations in some, but not all treated patients to an unpredictable extent, but are further limited by administration logistics and cost.

AREAS COVERED

An overview of the cellular and molecular immunopathology of asthma, highlighting the need and logic for the development of a novel, non-steroidal, small molecule drug for topical delivery targeting bronchial smooth muscle hyperresponsiveness and airways inflammation, particularly corticosteroid-refractory inflammation.

EXPERT OPINION

This article elaborates evidence supporting the hypothesis that topically delivered, inhaled antagonists of the calcium-sensing receptor (CaSR) have the potential to meet these requirements, and the practicality of repurposing existing, small molecule CaSR antagonists (calcilytics) for this purpose.

Combined blockade of IL-25, IL-33 and TSLP mediates amplified inhibition of airway inflammation and remodelling in a murine model of asthma

BACKGROUND AND OBJECTIVE

Isolated blockade of IL-25, IL-33 and thymic stromal lymphopoietin (TSLP) has been shown to reduce airways inflammation and hyperresponsiveness in murine asthma model. The hypothesis that combined blockade of all three cytokines can accomplish this more effectively has never been addressed.

METHODS

We studied a murine asthma model employing sensitization and challenge with ovalbumin (OVA) or saline control. To discern the effects of IL-33 blockade, we compared outcomes in strain identical, wild-type and IL-33 receptor (St2 ^-/- ) gene-deleted mice. We then examined, in the St2 ^-/- animals, the effects of additional, single or combined blockade of IL-25 and TSLP with blocking antibodies. Outcomes included airways reactivity, inflammatory cellular infiltration, epithelial cell metaplasia, deposition of fibrosis-related proteins, local Th2-type cytokine expression and total and specific serum IgE concentrations measured by ELISA and quantitative immunohistochemistry.

RESULTS

St2 ^-/- gene deletion significantly reduced airways reactivity, inflammatory cellular infiltration, lung tissue expression of Th2 cytokines and fibrosis related proteins and serum total IgE in response to OVA sensitization and challenge. Additional administration of anti-IL-25 and anti-TSLP blocking antibodies to the St2 ^-/- mice further significantly reduced inflammation, Th2 cytokine expression, airways fibrosis and IgE production, while anti-TSLP alone reduced eosinophil infiltration and local IL-4 expression. The airways inflammatory cellular infiltrate and lung tissue expression of Th2 cytokine, but not fibrosis-related proteins were also reduced in the presence of isotype identical, control antibodies.

CONCLUSION

Combined blockade of these three cytokines may better ameliorate airways pathological changes in this murine asthma model, with implications for human asthma.

Asthma from immune pathogenesis to precision medicine

Asthma is characterized by multiple immunological mechanisms (endotypes) determining variable clinical presentations (phenotypes). The identification of endotypic mechanisms is crucial to better characterize patients and to identify tailored therapeutic approaches with novel biological agents targeting specific immunological pathways. This review focused on summarizing the major immunological mechanisms involved in the pathogenesis of asthma, as well as on discussing the emergence of phenotypic features of the disease. Novel biological agents and other drugs targeting specific endotypes are discussed, as their use represent a precision medicine approach to the disease that is nowadays mandatory particularly for treating more severe patients.

Insulin‑like growth factor 1 inhibits phagocytosis of alveolar epithelial cells in asthmatic mice

The phagocytosis of apoptotic cells by alveolar epithelial cells helps to eliminate airway inflammation. Insulin‑like growth factor 1 (IGF‑1) regulates cell metabolism and proliferation, and promotes cell survival, while it may also promote the proliferation and differentiation of alveolar epithelial cells during the repair of lung injury. The present study investigated the effect of IGF‑1 on the phagocytic activity of alveolar epithelial cells, a nonprofessional phagocyte. IGF‑1 was elevated in lung tissue and bronchoalveolar lavage fluid obtained from mice with ovalbumin‑induced asthma. IGF‑1 was reduced by 50% in the lung tissue and by nearly 100% in the bronchoalveolar lavage fluid in asthmatic mice established by depletion of alveolar macrophages using 2‑chloroadenosine. In addition, interleukin‑33 induced IGF‑1 production in primary alveolar macrophages. It was also observed that IGF‑1 inhibited the phagocytosis of fluorescent microspheres and apoptotic cells by MLE‑12 alveolar epithelial cells. Antibody blocking of IGF‑1 enhanced the phagocytosis of fluorescent microspheres and apoptotic cells, and significantly reduced inflammatory cell infiltration in airway and perivascular tissues. The elevated IGF‑1 level in the lungs of asthma model mice was mainly produced in alveolar macrophages. Taken together, the current study demonstrated that IGF‑1 inhibited phagocytosis by alveolar epithelial cells, and that IGF‑1 blockade enhanced the phagocytic activity and alleviated airway inflammation. These results support the potential use of IGF‑1 as a target in the treatment of asthma.

Potential Role of Interleukin-25/Interleukin-33/Thymic Stromal Lymphopoietin-Fibrocyte Axis in the Pathogenesis of Allergic Airway Diseases

Objective:

Allergic airway diseases (AADs) are a group of heterogeneous disease mediated by T-helper type 2 (Th2) immune response and characterized with airway inflammation and remodeling, including allergic asthma, allergic rhinitis, and chronic rhinosinusitis with allergic background. This review aimed to discuss the abnormal epithelial-mesenchymal crosstalk in the pathogenesis of AADs.

Data Sources:

Articles referred in this review were collected from the database of PubMed published in English up to January 2018.

Study Selection:

We had done a literature search using the following terms “allergic airway disease OR asthma OR allergic rhinitis OR chronic sinusitis AND IL-25 OR IL-33 OR thymic stromal lymphopoietin OR fibrocyte”. Related original or review articles were included and carefully analyzed.

Results:

It is now believed that abnormal epithelial-mesenchymal crosstalk underlies the pathogenesis of AADs. However, the key regulatory factors and molecular events involved in this process still remain unclear. Epithelium-derived triple cytokines, including interleukin (IL)-25, IL-33, and thymic stromal lymphopoietin (TSLP), are shown to act on various target cells and promote the Th2 immune response. Circulating fibrocyte is an important mesenchymal cell that can mediate tissue remodeling. We previously found that IL-25-circulating fibrocyte axis was significantly upregulated in patients with asthma, which may greatly contribute to asthmatic airway inflammation and remodeling.

Conclusions:

In view of the redundancy of cytokines and “united airway” theory, we propose a new concept that IL-25/IL-33/TSLP-fibrocyte axis may play a vital role in the abnormal epithelial-mesenchymal crosstalk in some endotypes of AADs. This novel idea will guide potential new intervention schema for the common treatment of AADs sharing common pathogenesis in the future.

IL-25 protects against high-fat diet-induced hepatic steatosis in mice by inducing IL-25 and M2a macrophage production

Interleukin (IL)-25 is a cytokine that has previously been shown to have a protective role against nonalcoholic fatty liver disease (NAFLD), which is associated with the induction of M2 macrophage differentiation. However, the direct relationships between IL-25 expression regulation, M2 induction and NAFLD remain unknown. In this study, we demonstrate that IL-25 promotes hepatic macrophage differentiation into M2a macrophages both in vivo and in vitro via the IL-13/STAT6 pathway. M2 macrophages that were differentiated in vitro were able to ameliorate high-fat diet HFD-induced hepatic steatosis. Furthermore, we found that IL-25 treatment, both in vitro and in vivo, promotes direct binding of STAT6 to the IL-25 gene promoter region. This binding of STAT6 in response to IL-25 treatment also resulted in the increase of IL-25 expression in hepatocytes. Together, these findings identify IL-25 as a protective factor against HFD-induced hepatic steatosis by inducing an increase of IL-25 expression in hepatocytes and through promotion of M2a macrophage production.

Angiogenesis in the lung

Both systemic (tracheal and bronchial) and pulmonary circulations perfuse the lung. However, documentation of angiogenesis of either is complicated by the presence of the other. Well-documented angiogenesis of the systemic circulations have been identified in asthma, cystic fibrosis, chronic thromboembolism and primary carcinomas. Angiogenesis of the vasa vasorum, which are branches of bronchial arteries, is seen in the walls of large pulmonary vessels after a period of chronic hypoxia. Documentation of increased pulmonary capillaries has been shown in models of chronic hypoxia, after pneumonectomy and in some carcinomas. Although endothelial cell proliferation may occur as part of the repair process in several pulmonary diseases, it is separate from the unique establishment of new functional perfusing networks defined as angiogenesis. Identification of the mechanisms driving the expansion of new vascular beds in the adult needs further investigation. Yet the growth factors and molecular mechanisms of lung angiogenesis remain difficult to separate from underlying disease sequelae.

Insulin-Like Growth Factor-1 Signaling in Lung Development and Inflammatory Lung Diseases

Insulin-like growth factor-1 (IGF-1) was firstly identified as a hormone that mediates the biological effects of growth hormone. Accumulating data have indicated the role of IGF-1 signaling pathway in lung development and diseases such as congenital disorders, cancers, inflammation, and fibrosis. IGF-1 signaling modulates the development and differentiation of many types of lung cells, including airway basal cells, club cells, alveolar epithelial cells, and fibroblasts. IGF-1 signaling deficiency results in alveolar hyperplasia in humans and disrupted lung architecture in animal models. The components of IGF-1 signaling pathways are potentiated as biomarkers as they are dysregulated locally or systemically in lung diseases, whereas data may be inconsistent or even paradoxical among different studies. The usage of IGF-1-based therapeutic agents urges for more researches in developmental disorders and inflammatory lung diseases, as the majority of current data are collected from limited number of animal experiments and are generally less exuberant than those in lung cancer. Elucidation of these questions by further bench-to-bedside researches may provide us with rational clinical diagnostic approaches and agents concerning IGF-1 signaling in lung diseases.

IL-25 dampens the growth of human germinal center-derived B-cell non Hodgkin Lymphoma by curtailing neoangiogenesis

Interleukin (IL)-25, a member of the IL-17 cytokine superfamily, is produced by immune and non-immune cells and exerts type 2 pro-inflammatory effects in vitro and in vivo. The IL-25 receptor(R) is composed of the IL-17RA/IL-17RB subunits. Previous work showed that germinal centre (GC)-derived B-cell non Hodgkin lymphomas (B-NHL) expressed IL-17AR, formed by IL-17RA and IL-17RC subunits, and IL-17A/IL-17AR axis promoted B-NHL growth by stimulating neoangiogenesis. Here, we have investigated expression and function of IL-25/IL-25R axis in lymph nodes from human GC-derived B-NHL, i.e. Follicular Lymphoma (FL,10 cases), Diffuse Large B Cell Lymphoma (6 cases) and Burkitt Lymphoma (3 cases). Tumor cells expressed IL-25R and IL-25 that was detected also in non-malignant cells by flow cytometry. Immunohistochemical studies confirmed expression of IL-25R and IL-25 in FL cells, and highlighted IL-25 expression in bystander elements of the FL microenvironment. IL-25 i) up-regulated phosphorylation of NFkBp65, STAT-1 and JNK in B-NHL cells; ii) inhibited in vitro proliferation of the latter cells; iii) exerted anti-tumor activity in two in vivo B-NHL models by dampening expression of pro-angiogenic molecules as VEGF-C, CXCL6 and ANGPT3. In conclusion, IL-25, that is intrinsically pro-angiogenic, inhibits B-NHL growth by reprogramming the angiogenic phenotype of B-NHL cells.

Therapeutic efficacy of a co-blockade of IL-13 and IL-25 on airway inflammation and remodeling in a mouse model of asthma

Repeated airway inflammation and unremitting remodeling provoke irreversible pulmonary dysfunction and resistance to current drugs in patients with chronic bronchial asthma. Interleukin (IL)-13 and IL-25 play an important role in airway inflammation and remodeling in asthma. We aimed to investigate whether co-inhibiting IL-13 and IL-25 can effectively down-regulate allergen-induced airway inflammation and remodeling in mice. Mice with asthma induced by chronic exposure to ovalbumin (OVA) were given soluble IL-13 receptor α2 (sIL-13R) or soluble IL-25 receptor (sIL-25R) protein alone and in combination to neutralize the bioactivity of IL-13 and IL-25, and relevant airway inflammation and remodeling experiments were performed. We found that the co-blockade of IL-13 and IL-25 with sIL-13R and sIL-25R was more effective than either agent alone at decreasing inflammatory cell infiltration, airway hyperresponsiveness (AhR) and airway remodeling including mucus production, extracellular collagen deposition, smooth muscle cell hyperplasia and angiogenesis in mice exposed to OVA. These results suggest that the combined inhibition of IL-13 and IL-25 may provide a novel therapeutic strategy for asthma, especially for patients who are resistant to current treatments.

Cnidium officinale extract and butylidenephthalide inhibits retinal neovascularization in vitro and in vivo

BACKGROUND

Retinal neovascularization, which is the pathological growth of new blood vessels, is associated with retinopathy of prematurity, neovascular age-related macular degeneration, diabetic retinopathy and retinal vein occlusion. In this study, we evaluated the effect of an extract of Cnidium officinale Makino (COE) and its bioactive compound, butylidenephthalide (BP), on the migration and tube formation of human umbilical vein endothelial cells (HUVECs), and on retinal pathogenic neovascularization in the oxygen-induced retinopathy (OIR) mouse model.

METHOD

The HUVECs were incubated with COE and BP (0.1-10 μg/ml). The mice were exposed to 75 % oxygen for 5 days starting on the 7(th) postnatal day (P7-P12). Then, the mice were returned to room air and intraperitoneally injected with COE (100 mg/kg) and BP (5 mg/kg) once per day for 5 days (P12-P16). On P17, we measured retinal neovascularization and analyzed the angiogenesis-related proteins expression using protein arrays.

RESULTS

COE and BP inhibit the HUVECs migration and the tube formation in a dose-dependent manner. In addition, COE significantly decreased retinal neovascularization in the OIR mice. COE reduced the expression levels of AREG, ANG, DLL4, Endostatin, IGFBP-2 and VEGF. Additionally, BP also inhibited the retinal neovascularization and down-regulated the expression of AREG, ANG, DLL4 and VEGF.

CONCLUSION

These results suggest that COE and BP exerts antiangiogenic effects on retinal neovascularization by inhibiting the expression of AREG, ANG, DLL4 and VEGF, indicating that antiangiogenic activities of COE may be in part due to its bioactive compound, BP.

Specific immunotherapy generates CD8(+) CD196(+) T cells to suppress lung cancer growth in mice

That specific immunotherapy can inhibit cancer growth has been recognized; its efficiency is to be improved. This study aimed to inhibit lung cancer (LC) growth in a mouse model by using an LC-specific vaccination. In this study, a LC mouse model was created by adoptive transplantation with LC cells. The tumor-bearing mice were vaccinated with LC cell extracts plus adjuvant TNBS or adoptive transplantation with specific CD8(+) CD196(+) T cells. The results showed that the vaccination with LC extracts (LCE)/TNBS markedly inhibited the LC growth and induced CD8(+) CD196(+) T cells in LC tissue and the spleen. These CD8(+) CD196(+) T cells proliferated and produce high levels of perforin upon exposure to LCE and specifically induced LC cell apoptosis. Exposure to TNBS induced RAW264.7 cells to produce macrophage inflammatory protein-3α; the latter activated signal transducer and activator of transcription 3 and further induced perforin expression in the CD8(+) CD196(+) T cells. Adoptive transfer with specific CD8(+) CD196(+) T cells suppressed LC growth in mice. In conclusion, immunization with LC extracts and TNBS can induce LC-specific CD8(+) CD196(+) T cells in LC-bearing mice and inhibit LC growth.

Interleukin (IL)-25: Pleiotropic roles in asthma

IL-25, also named IL-17E, is a distinct member of the IL-17 cytokine family, which can promote and augment T helper type 2 (Th2) responses locally or systemically. Growing evidence from experimental and clinical studies indicates that the expression of IL-25 and its cognate receptor, IL-17RB/RA, is markedly upregulated in asthmatic conditions. It has also been found that IL-25 induces not only typical eosinophilic inflammation and airway hyperresponsiveness (AHR), but also airway remodelling, manifested by goblet cell hyperplasia, subepithelial collagen deposition and angiogenesis. This review will focus on the discovery, cellular origins and targets of IL-25, and try to update current animal and human studies elucidating the roles of IL-25 in asthma. We conclude that although IL-25 is a pleiotropic cytokine, it may only play its dominant role in a certain specific asthmatic endotype, named 'IL-25 high' phenotype. Thus, targeting IL-25 or its receptor might selectively benefit some subgroups with asthma. Furthermore, the major IL-25 producing as well as responsive cells in the changeable milieu of asthma should be assessed in the future.