Exclusive neutrophil recruitment with oncostatin M in a human system

Nomogram incorporating prognostic immune-inflammatory-nutritional score for survival prediction in pancreatic cancer: a retrospective study

BACKGROUND

Prognosis prediction for pancreatic cancer has always been difficult in clinical practice because of its high heterogeneity and mortality. The aim of the study was to assess the value of prognostic immune-inflammatory-nutritional (PIIN) score on overall survival (OS) in postoperative patients with pancreatic cancer and to develop a nomogram incorporating PIIN score.

METHODS

This study retrospectively analyzed the clinic pathological data of 155 patients with pancreatic cancer who underwent radical surgery. PIIN score was calculated by measuring the fibrinogen (FIB), neutrophil to lymphocyte ratio (NLR), systemic immune-inflammation index (SII), albumin-bilirubin (ALBI) score, and prognostic nutritional index (PNI). Patients were divided into two groups by PIIN score levels over a threshold of 37.2. Univariate and multivariate analysis were performed using the Cox regression analysis model. The time-dependent receiver operating characteristic (ROC) curve was plotted to compare the prognostic values of the scoring systems. Finally, a nomogram based on PIIN score was constructed and validated.

RESULTS

Multivariate regression analysis showed that PIIN score (hazard ratio (HR) = 2.171, 95% confidence interval (CI) = 1.207-3.906, P = 0.010), lymphovascular invasion (HR = 1.663, 95% CI = 1.081-2.557, P = 0.021), poor tumor grade (HR = 2.577, 95% CI = 1.668-3.982, P < 0.001), bad TNM stage (I vs. II: HR = 1.791, 95% CI = 1.103-2.906, P = 0.018; I vs. III: HR = 4.313, 95% CI = 2.365-7.865, P < 0.001) and without adjuvant chemotherapy (HR = 0.552, 95% CI = 0.368-0.829, P = 0.004) were independent risk factors for OS. The time-dependent ROC curves revealed that PIIN score was better than the other scoring systems in predicting survival prognosis. And last, the nomogram established from independent factors such as PIIN score had good predictive power for OS. The ROC curve results showed that the AUC values for 1, 3 and 5 years were 0.826, 0.798 and 0.846, respectively. The calibration plots showed the superior clinical applicability of the nomogram.

CONCLUSION

The nomogram model based on PIIN score can be utilized as one of the prognosis stratifications as well as postoperative follow-up for the development of individual treatment for pancreatic cancer.

Single-Cell Profiling of Tumor-Associated Neutrophils in Advanced Non-Small Cell Lung Cancer

Purpose

Neutrophils act as a non-negligible regulator in the initiation and progression of malignancies, playing bifacial roles in the process. Thus, to understand the heterogeneity of tumor-associated neutrophils (TANs) comprehensively in advanced non-small cell lung cancer (NSCLC) at single-cell resolution is necessary and urgent.

Materials and Methods

We applied single-cell RNA-sequencing (scRNA-seq) to portray the subtype-specific transcriptome landscape of TANs in advanced NSCLC using nine freshly obtained specimens. The scRNA-seq data were further processed for pseudo-time analysis to depict the developmental trajectory of TANs. Meanwhile, the interplay between TANs and other cell types within tumor microenvironment (TME) was revealed by intercellular interaction analysis.

Results

Seven distinct TAN subtypes were defined, of which, the N3 cluster was considered inflammatory phenotype expressing genes encoding multiple chemotactic cytokines, and correlated with inferior overall survival, indicating that N3 might be a pro-tumorigenic TAN subtype. N1 and N5 clusters were considered to be well differentiated and mature neutrophils based on CXCR2 expression and pseudo-time patterns, and both accounted for relatively high proportions in lung adenocarcinoma. In addition, genes related to neutrophil differentiation were discovered. We also found that TAN subtypes interacted most closely with macrophages through chemokine signaling pathways within TME.

Conclusion

Our study refined TAN subtypes and mapped the transcriptome landscape of TANs at single-cell resolution in advanced NSCLC, collectively indicating the heterogeneity of TANs in NSCLC. Neutrophil differentiation- and maturation-related genes were also discovered, which shed light on different functions of TAN subclones in tumor immune escape, and may further provide novel targets for immunotherapy.

Integrative transcriptomic analysis in human and mouse model of anaphylaxis identifies gene signatures associated with cell movement, migration and neuroinflammatory signalling

Background

Anaphylaxis is an acute life-threatening allergic reaction and a concern at a global level; therefore, further progress in understanding the underlying mechanisms and more effective strategies for diagnosis, prevention and management are needed.

Objective

We sought to identify the global architecture of blood transcriptomic features of anaphylaxis by integrating expression data from human patients and mouse model of anaphylaxis.

Methods

Bulk RNA-sequencings of peripheral whole blood were performed in: i) 14 emergency department (ED) patients with acute anaphylaxis, predominantly to Hymenoptera venom, ii) 11 patients with peanut allergy undergoing double-blind, placebo-controlled food challenge (DBPCFC) to peanut, iii) murine model of IgE-mediated anaphylaxis. Integrative characterisation of differential gene expression, immune cell-type-specific gene expression profiles, and functional and pathway analysis was undertaken.

Results

1023 genes were commonly and significantly dysregulated during anaphylaxis in ED and DBPCFC patients; of those genes, 29 were also dysregulated in the mouse model. Cell-type-specific gene expression profiles showed a rapid downregulation of blood basophil and upregulation of neutrophil signature in ED and DBPCFC patients and the mouse model, but no consistent and/or significant differences were found for other blood cells. Functional and pathway analysis demonstrated that human and mouse blood transcriptomic signatures of anaphylaxis follow trajectories of upregulation of cell movement, migration and neuroinflammatory signalling, and downregulation of lipid activating nuclear receptors signalling.

Conclusion

Our study highlights the matched and extensive blood transcriptomic changes and suggests the involvement of discrete cellular components and upregulation of migration and neuroinflammatory pathways during anaphylaxis.

Neutrophil extracellular traps: New players in cancer research

NETs are chromatin-derived webs extruded from neutrophils as a result of either infection or sterile stimulation using chemicals, cytokines, or microbes. In addition to the classical role that NETs play in innate immunity against infection and injuries, NETs have been implicated extensively in cancer progression, metastatic dissemination, and therapy resistance. The purpose of this review is to describe recent investigations into NETs and the roles they play in tumor biology and to explore their potential as therapeutic targets in cancer treatment.

Oncostatin M triggers brain inflammation by compromising blood-brain barrier integrity

Oncostatin M (OSM) is an IL-6 family member which exerts neuroprotective and remyelination-promoting effects after damage to the central nervous system (CNS). However, the role of OSM in neuro-inflammation is poorly understood. Here, we investigated OSM's role in pathological events important for the neuro-inflammatory disorder multiple sclerosis (MS). We show that OSM receptor (OSMRβ) expression is increased on circulating lymphocytes of MS patients, indicating their elevated responsiveness to OSM signalling. In addition, OSM production by activated myeloid cells and astrocytes is increased in MS brain lesions. In experimental autoimmune encephalomyelitis (EAE), a preclinical model of MS, OSMRβ-deficient mice exhibit milder clinical symptoms, accompanied by diminished T helper 17 (Th17) cell infiltration into the CNS and reduced BBB leakage. In vitro, OSM reduces BBB integrity by downregulating the junctional molecules claudin-5 and VE-cadherin, while promoting secretion of the Th17-attracting chemokine CCL20 by inflamed BBB-endothelial cells and reactive astrocytes. Using flow cytometric fluorescence resonance energy transfer (FRET) quantification, we found that OSM-induced endothelial CCL20 promotes activation of lymphocyte function-associated antigen 1 (LFA-1) on Th17 cells. Moreover, CCL20 enhances Th17 cell adhesion to OSM-treated inflamed endothelial cells, which is at least in part ICAM-1 mediated. Together, these data identify an OSM-CCL20 axis, in which OSM contributes significantly to BBB impairment during neuro-inflammation by inducing permeability while recruiting Th17 cells via enhanced endothelial CCL20 secretion and integrin activation. Therefore, care should be taken when considering OSM as a therapeutic agent for treatment of neuro-inflammatory diseases such as MS.

Mechanistic insights into the interplays between neutrophils and other immune cells in cancer development and progression

Cancer is considered a major public health concern worldwide and is characterized by an uncontrolled division of abnormal cells. The human immune system recognizes cancerous cells and induces innate immunity to destroy those cells. However, sustained tumors may protect themselves by developing immune escape mechanisms through multiple soluble and cellular mediators. Neutrophils are the most plenteous leukocytes in the human blood and are crucial for immune defense in infection and inflammation. Besides, neutrophils emancipate the antimicrobial contents, secrete different cytokines or chemokines, and interact with other immune cells to combat and successfully kill cancerous cells. Conversely, many clinical and experimental studies signpost that being a polarized and heterogeneous population with plasticity, neutrophils, particularly their subpopulations, act as a modulator of cancer development by promoting tumor metastasis, angiogenesis, and immunosuppression. Studies also suggest that tumor infiltrating macrophages, neutrophils, and other innate immune cells support tumor growth and survival. Additionally, neutrophils promote tumor cell invasion, migration and intravasation, epithelial to mesenchymal transition, survival of cancer cells in the circulation, seeding, and extravasation of tumor cells, and advanced growth and development of cancer cells to form metastases. In this manuscript, we describe and review recent studies on the mechanisms for neutrophil recruitment, activation, and their interplay with different immune cells to promote their pro-tumorigenic functions. Understanding the detailed mechanisms of neutrophil-tumor cell interactions and the concomitant roles of other immune cells will substantially improve the clinical utility of neutrophils in cancer and eventually may aid in the identification of biomarkers for cancer prognosis and the development of novel therapeutic approaches for cancer treatment.

New Insight Into Neutrophils: A Potential Therapeutic Target for Cerebral Ischemia

Ischemic stroke is one of the main issues threatening human health worldwide, and it is also the main cause of permanent disability in adults. Energy consumption and hypoxia after ischemic stroke leads to the death of nerve cells, activate resident glial cells, and promote the infiltration of peripheral immune cells into the brain, resulting in various immune-mediated effects and even contradictory effects. Immune cell infiltration can mediate neuronal apoptosis and aggravate ischemic injury, but it can also promote neuronal repair, differentiation and regeneration. The central nervous system (CNS), which is one of the most important immune privileged parts of the human body, is separated from the peripheral immune system by the blood-brain barrier (BBB). Under physiological conditions, the infiltration of peripheral immune cells into the CNS is controlled by the BBB and regulated by the interaction between immune cells and vascular endothelial cells. As the immune response plays a key role in regulating the development of ischemic injury, neutrophils have been proven to be involved in many inflammatory diseases, especially acute ischemic stroke (AIS). However, neutrophils may play a dual role in the CNS. Neutrophils are the first group of immune cells to enter the brain from the periphery after ischemic stroke, and their exact role in cerebral ischemia remains to be further explored. Elucidating the characteristics of immune cells and their role in the regulation of the inflammatory response may lead to the identification of new potential therapeutic strategies. Thus, this review will specifically discuss the role of neutrophils in ischemic stroke from production to functional differentiation, emphasizing promising targeted interventions, which may promote the development of ischemic stroke treatments in the future.

Neutrophil-derived granule cargoes: paving the way for tumor growth and progression

Neutrophils are the key cells of our innate immune system mediating host defense via a range of effector functions including phagocytosis, degranulation, and NETosis. For this, they employ an arsenal of anti-microbial cargoes packed in their readily mobilizable granule subsets. Notably, the release of granule content is tightly regulated; however, under certain circumstances, their unregulated release can aggravate tissue damage and could be detrimental to the host. Several constituents of neutrophil granules have also been associated with various inflammatory diseases including cancer. In cancer setting, their excessive release may modulate tissue microenvironment which ultimately leads the way for tumor initiation, growth and metastasis. Neutrophils actively infiltrate within tumor tissues, wherein they show diverse phenotypic and functional heterogeneity. While most studies are focused at understanding the phenotypic heterogeneity of neutrophils, their functional heterogeneity, much of which is likely orchestrated by their granule cargoes, is beginning to emerge. Therefore, a better understanding of neutrophil granules and their cargoes will not only shed light on their diverse role in cancer but will also reveal them as novel therapeutic targets. This review provides an overview on existing knowledge of neutrophil granules and detailed insight into the pathological relevance of their cargoes in cancer. In addition, we also discuss the therapeutic approach for targeting neutrophils or their microenvironment in disease setting that will pave the way forward for future research.

Oncostatin M: A mysterious cytokine in cancers

Oncostatin M (OSM), as a member of the Interleukin-6 family cytokines, plays a significant role in inflammation, autoimmunity, and cancers. It is mainly secreted by T lymphocytes, neutrophils, and macrophages and was initially introduced as anti-cancer agent. However, in some cases, it promotes cancer progression. Overexpression of OSM and OSM receptor has been detected in various cancers including colon cancer, breast cancer, pancreatic cancer, myeloma, brain tumors, chronic lymphocytic leukemia, and hepatoblastoma. STAT3 is the main downstream signaling molecule of OSM, which operates the leading role in modifications of cancer cells and enhancing cell growth, invasion, survival, and all other hallmarks of cancer cells. However, due to the presence of multiple signaling pathways, it can act contradictory in some cancers. In this review, we will discuss the emerging roles of OSM in cancer and elucidate its function in tumor control or progression and finally discuss therapeutic approaches designed to manipulate this cytokine in cancer.

Neutrophils activated by BJcuL, a C-type lectin isolated from Bothrops jararacussu venom, decrease the invasion potential of neuroblastoma SK-N-SH cells in vitro

BACKGROUND

Neuroblastoma is a pediatric tumor with a mortality rate of 40% in the most aggressive cases. Tumor microenvironment components as immune cells contribute to the tumor progression; thereby, the modulation of immune cells to a pro-inflammatory and antitumoral profile could potentialize the immunotherapy, a suggested approach for high-risk patients. Preview studies showed the antitumoral potential of BJcuL, a C- type lectin isolated from Bothrops jararacussu venom. It was able to induce immunomodulatory responses, promoting the rolling and adhesion of leukocytes and the activation of neutrophils.

METHODS

SK-N-SH cells were incubated with conditioned media (CM) obtained during the treatment of neutrophils with BJcuL and fMLP, a bacteria-derived peptide highly effective for activating neutrophil functions. Then we evaluated the effect of the same stimulation on the co-cultivation of neutrophils and SK-N-SH cells. Tumor cells were tested for viability, migration, and invasion potential.

RESULTS

In the viability assay, only neutrophils treated with BJcuL (24 h) and cultivated with SK-N-SH were cytotoxic. Migration of tumor cells decreased when incubated directly (p < 0.001) or indirectly (p < 0.005) with untreated neutrophils. When invasion potential was evaluated, neutrophils incubated with BJcuL reduced the total number of colonies of SK-N-SH cells following co-cultivation for 24 h (p < 0.005). Treatment with CM resulted in decreased anchorage-free survival following 24 h of treatment (p < 0.001).

CONCLUSION

Data demonstrated that SK-N-SH cells maintain their migratory potential in the face of neutrophil modulation by BJcuL, but their invasive capacity was significantly reduced.

Endothelial signaling by neutrophil-released oncostatin M enhances P-selectin-dependent inflammation and thrombosis

In the earliest phase of inflammation, histamine and other agonists rapidly mobilize P-selectin to the apical membranes of endothelial cells, where it initiates rolling adhesion of flowing neutrophils. Clustering of P-selectin in clathrin-coated pits facilitates rolling. Inflammatory cytokines typically signal by regulating gene transcription over a period of hours. We found that neutrophils rolling on P-selectin secreted the cytokine oncostatin M (OSM). The released OSM triggered signals through glycoprotein 130 (gp130)-containing receptors on endothelial cells that, within minutes, further clustered P-selectin and markedly enhanced its adhesive function. Antibodies to OSM or gp130, deletion of the gene encoding OSM in hematopoietic cells, or conditional deletion of the gene encoding gp130 in endothelial cells inhibited neutrophil rolling on P-selectin in trauma-stimulated venules of the mouse cremaster muscle. In a mouse model of P-selectin-dependent deep vein thrombosis, deletion of OSM in hematopoietic cells or of gp130 in endothelial cells markedly inhibited adhesion of neutrophils and monocytes and the rate and extent of thrombus formation. Our results reveal a paracrine-signaling mechanism by which neutrophil-released OSM rapidly influences endothelial cell function during physiological and pathological inflammation.

The Complex Interaction between the Tumor Micro-Environment and Immune Checkpoints in Breast Cancer

The progression of breast cancer and its association with clinical outcome and treatment remain largely unexplored. Accumulating data has highlighted the interaction between cells of the immune system and the tumor microenvironment in cancer progression, and although studies have identified multiple facets of cancer progression within the development of the tumor microenvironment (TME) and its constituents, there is lack of research into the associations between breast cancer subtype and staging. Current literature has provided insight into the cells and pathways associated with breast cancer progression through expression analysis. However, there is lack of co-expression studies between immune pathways and cells of the TME that form pro-tumorigenic relationships contributing to immune-evasion. We focus on the immune checkpoint and TME elements that influence cancer progression, particularly studies in molecular subtypes of breast cancer.

Neutrophil plasticity in the tumor microenvironment

Neutrophils act as the body's first line of defense against infection and respond to diverse inflammatory cues, including cancer. Neutrophils display plasticity, with the ability to adapt their function in different inflammatory contexts. In the tumor microenvironment, neutrophils have varied functions and have been classified using different terms, including N1/N2 neutrophils, tumor-associated neutrophils, and polymorphonuclear neutrophil myeloid-derived suppressor cells (PMN-MDSCs). These populations of neutrophils are primarily defined by their functional phenotype, because few specific cell surface markers have been identified. In this review, we will discuss neutrophil polarization and plasticity and the function of proinflammatory/anti-inflammatory and protumor/antitumor neutrophils in the tumor microenvironment. We will also discuss how neutrophils with the ability to suppress T-cell activation, referred to by some as PMN-MDSCs, fit into this paradigm.

Coordination of Immune-Stroma Crosstalk by IL-6 Family Cytokines

Stromal cells are a subject of rapidly growing immunological interest based on their ability to influence virtually all aspects of innate and adaptive immunity. Present in every bodily tissue, stromal cells complement the functions of classical immune cells by sensing pathogens and tissue damage, coordinating leukocyte recruitment and function, and promoting immune response resolution and tissue repair. These diverse roles come with a price: like classical immune cells, inappropriate stromal cell behavior can lead to various forms of pathology, including inflammatory disease, tissue fibrosis, and cancer. An important immunological function of stromal cells is to act as information relays, responding to leukocyte-derived signals and instructing leukocyte behavior in kind. In this regard, several members of the interleukin-6 (IL-6) cytokine family, including IL-6, IL-11, oncostatin M (OSM), and leukemia inhibitory factor (LIF), have gained recognition as factors that mediate crosstalk between stromal and immune cells, with diverse roles in numerous inflammatory and homeostatic processes. This review summarizes our current understanding of how IL-6 family cytokines control stromal-immune crosstalk in health and disease, and how these interactions can be leveraged for clinical benefit.

Distinct Functions of Neutrophil in Cancer and Its Regulation

Neutrophils are the most abundant of all white blood cells in the human circulation and are usually associated with inflammation and with fighting infections. In recent years the role immune cells play in cancer has been a matter of increasing interest. In this context the function of neutrophils is controversial as neutrophils were shown to possess both tumor promoting and tumor limiting properties. Here we provide an up-to-date review of the pro- and antitumor properties neutrophils possess as well as the environmental cues that regulate these distinct functions.

Oncostatin M induces IL-33 expression in liver endothelial cells in mice and expands ST2+CD4+ lymphocytes

Interleukin (IL)-33 is crucially involved in liver pathology and drives hepatoprotective functions. However, the regulation of IL-33 by cytokines of the IL-6 family, including oncostatin M (OSM) and IL-6, is not well studied. The aim of the present study was to determine whether OSM mediates regulation of IL-33 expression in liver cells. Intramuscular administration in mice of an adenovirus encoding OSM (AdOSM) leads to increase in expression of OSM in muscles, liver, and serum of AdOSM-infected mice compared with control mice. The increase of circulating OSM markedly regulated mRNA of genes associated with blood vessel biology, chemotaxis, cellular death, induction of cell adhesion molecules, and the alarmin cytokine IL-33 in liver. Steady-state IL-33 mRNA was upregulated by OSM at an early phase (8 h) following AdOSM infection. At the protein level, the expression of IL-33 was significantly induced in liver endothelial cells [liver sinusoidal endothelial cells (LSEC) and vascular endothelial cells] with a peak at 8 days post-AdOSM infection in mice. In addition, we found OSM-stimulated human microvascular endothelial HMEC-1 cells and human LSEC/TRP3 cells showed a significant increase in expression of IL-33 mRNA in a dose-dependent manner in cell culture. The OSM-mediated overexpression of IL-33 was associated with the activation/enrichment of CD4(+)ST2(+) cells in liver of AdOSM-infected mice compared with adenovirus encoding green fluorescent protein-treated control mice. In summary, these data suggest that the cytokine OSM regulates the IL-33 expression in liver endothelial cells in vivo and in HMEC-1/TRP3 cells in vitro and may specifically expand the target CD4(+)ST2(+) cells in liver.

Oncostatin M binds to extracellular matrix in a bioactive conformation: implications for inflammation and metastasis

Oncostatin M (OSM) is an interleukin-6-like inflammatory cytokine reported to play a role in a number of pathological processes including cancer. Full-length OSM is expressed as a 26 kDa protein that can be proteolytically processed into 24 kDa and 22 kDa forms via removal of C-terminal peptides. In this study, we examined both the ability of OSM to bind to the extracellular matrix (ECM) and the activity of immobilized OSM on human breast carcinoma cells. OSM was observed to bind to ECM proteins collagen types I and XI, laminin, and fibronectin in a pH-dependent fashion, suggesting a role for electrostatic bonds that involves charged amino acids of both the ECM and OSM. The C-terminal extensions of 24 kDa and 26 kDa OSM, which contains six and thirteen basic amino acids, respectively, enhanced electrostatic binding to ECM at pH 6.5-7.5 when compared to 22 kDa OSM. The highest levels of OSM binding to ECM, though, were observed at acidic pH 5.5, where all forms of OSM bound to ECM proteins to a similar extent. This indicates additional electrostatic binding properties independent of the OSM C-terminal extensions. The reducing agent dithiothreitol also inhibited the binding of OSM to ECM suggesting a role for disulfide bonds in OSM immobilization. OSM immobilized to ECM was protected from cleavage by tumor-associated proteases and maintained activity following incubation at acidic pH for extended periods of time. Importantly, immobilized OSM remained biologically active and was able to induce and sustain the phosphorylation of STAT3 in T47D and ZR-75-1 human breast cancer cells over prolonged periods, as well as increase levels of STAT1 and STAT3 protein expression. Immobilized OSM also induced epithelial-mesenchymal transition-associated morphological changes in T47D cells. Taken together, these data indicate that OSM binds to ECM in a bioactive state that may have important implications for the development of chronic inflammation and tumor metastasis.

Paeoniflorin suppresses vascular damage and the expression of E-selectin and ICAM-1 in a mouse model of cutaneous Arthus reaction

Paeoniflorin (PF) extracted from the root of Paeonia lactiflora pall, displays anti-inflammation properties in several animal models. Adhesion molecules are important for the recruitment of leucocyte to the vessel wall and involved in the pathogenesis of various autoimmune and inflammatory diseases. Herein, we investigate the effects of PF on adhesion molecule expression in a mouse model of cutaneous Arthus reaction and cultured human dermal microvascular endothelial cells (HDMECs). We showed that PF significantly ameliorated the immune complex (IC) induced vascular damage, leucocyte infiltrates and adhesion molecules expression. Furthermore, PF markedly blocked tumor necrosis factor-α (TNF-α)-induced E-selectin and intercellular adhesion molecule-1 (ICAM-1) expression in HDMECs at both mRNA and protein levels. PF also suppressed TNF-α-induced adhesion of polymorphonuclear leucocytes (PMNs) to HDMECs. Finally, western blot data revealed that PF can inhibit the phosphorylation of p38, JNK in TNF-α-treated HDMECs. These data suggest that PF, as an anti-inflammatory agent, can downregulate adhesion molecules expression. PF may be a candidate medicine for the treatment of IC-induced inflammatory response.

The enigmatic cytokine oncostatin m and roles in disease

Oncostatin M is a secreted cytokine involved in homeostasis and in diseases involving chronic inflammation. It is a member of the gp130 family of cytokines that have pleiotropic functions in differentiation, cell proliferation, and hematopoetic, immunologic, and inflammatory networks. However, Oncostatin M also has activities novel to mediators of this cytokine family and others and may have fundamental roles in mechanisms of inflammation in pathology. Studies have explored Oncostatin M functions in cancer, bone metabolism, liver regeneration, and conditions with chronic inflammation including rheumatoid arthritis, lung and skin inflammatory disease, atherosclerosis, and cardiovascular disease. This paper will review Oncostatin M biology in a historical fashion and focus on its unique activities, in vitro and in vivo, that differentiate it from other cytokines and inspire further study or consideration in therapeutic approaches.

TWEAK enhances E-selectin and ICAM-1 expression, and may contribute to the development of cutaneous vasculitis

Our previous work indicated that TWEAK is associated with various types of cutaneous vasculitis (CV). Herein, we investigate the effects of TWEAK on vascular injury and adhesion molecule expression in CV mice. We showed that TWEAK priming in mice induced a local CV. Furthermore, TWEAK priming also increased the extravasation of FITC-BSA, myeloperoxidase activity and the expression of E-selectin and ICAM-1. Conversely, TWEAK blockade ameliorated the LPS-induced vascular damage, leukocyte infiltrates and adhesion molecules expression in LPS-induced CV. In addition, TWEAK treatment of HDMECs up-regulated E-selectin and ICAM-1 expression at both mRNA and protein levels. TWEAK also enhanced the adhesion of PMNs to HDMECs. Finally, western blot data revealed that TWEAK can induce phosphorylation of p38, JNK and ERK in HDMECs. These data suggest that TWEAK acted as an inducer of E-selectin and ICAM-1 expression in CV mice and HDMECs, may contribute to the development of CV.

Potential of oncostatin M to accelerate diabetic wound healing

Oncostatin M (OSM) is a multifunctional cytokine found in a variety of pathologic conditions, which leads to excessive collagen deposition. Current studies demonstrate that OSM is also a mitogen for fibroblasts and has an anti-inflammatory action. It was therefore hypothesised that OSM may play an important role in healing of chronic wounds that usually involve decreased fibroblast function and persist in the inflammatory stage for a long time. In a previous in vitro study, the authors showed that OSM increased wound healing activities of diabetic dermal fibroblasts. However, wound healing in vivo is a complex process involving multiple factors. Thus, the purpose of this study was to evaluate the effect of OSM on diabetic wound healing in vivo. Five diabetic mice were used in this study. Four full-thickness round wounds were created on the back of each mouse (total 20 wounds). OSM was applied on the two left-side wounds (n = 10) and phosphate-buffered saline was applied on the two right-side wounds (n = 10). After 10 days, unhealed wound areas of the OSM and control groups were compared using the stereoimage optical topometer system. Also, epithelialisation, wound contraction and reduction in wound volume in each group were compared. The OSM-treated group showed superior results in all of the tested parameters. In particular, the unhealed wound area and the reduction in wound volume demonstrated statistically significant differences (P < 0·05). The results of this study indicate that topical application of OSM may have the potential to accelerate healing of diabetic wounds.

Endothelium-derived GM-CSF influences expression of oncostatin M

During and after transendothelial migration, neutrophils undergo a number of phenotypic changes resulting from encounters with endothelium-derived factors. This report uses an in vitro model with human umbilical vein endothelial cells and isolated human neutrophils to examine the effects of two locally derived cytokines, granulocyte (G)-macrophage (M) colony-stimulating factor (GM-CSF) and G-CSF, on oncostatin M (OSM) expression. Neutrophils contacting activated HUVEC expressed and released increased amounts of oncostatin M (OSM), a proinflammatory cytokine known to induce polymorphonuclear neutrophil adhesion and chemotaxis. Neutrophil transendothelial migration resulted in threefold higher OSM expression and protein levels compared with nontransmigrated cells. Addition of anti-GM-CSF neutralizing antibody reduced OSM expression level but anti-G-CSF was without effect. GM-CSF but not G-CSF protein addition to cultures of isolated neutrophils resulted in a significant increase in OSM protein secretion. However, inhibition of β(2) integrins by neutralizing antibody significantly reduced GM-CSF-induced OSM production indicating this phenomenon is adhesion dependent. Thus cytokine-stimulated endothelial cells can produce sufficient quantities of GM-CSF to influence in an adhesion-dependent manner, the phenotypic characteristics of neutrophils resulting in the latter's transmigration. Both transmigration and adhesion phenomenon lead to increased production of OSM by neutrophils that then play a major role in inflammatory response.

Oncostatin M (OSM) is increased in asthma with incompletely reversible airflow obstruction

Oncostatin M, a unique member of the interleukin (IL)-6 cytokine family, is thought to be involved in airway remodeling. The expression of oncostatin M in the lower airways is unknown. The aim of this study was to measure the sputum expression of oncostatin M in patients with asthma with and without irreversible airflow obstruction. Induced sputum was collected from nonsmoking adults with stable asthma (n = 53), 31 with incomplete reversibility of airflow obstruction. Peripheral blood cells were isolated and stimulated with lipopolysaccharide in 10 participants with asthma and irreversible airflow obstruction. Oncostatin M protein levels were determined in supernatant, whereas RNA was extracted to determine Oncostatin M mRNA expression using real-time polymerase chain reaction (PCR). Oncostatin M mRNA expression and protein levels were significantly higher in the sputum of asthmatics with irreversible airflow obstruction. Sputum oncostatin M levels were highest in people with severe airflow obstruction and were localized to airway neutrophils and macrophages. Peripheral blood neutrophils released more oncostatin M when stimulated with lipopolysaccharide compared with unstimulated neutrophils. Sputum oncostatin M is increased in asthma with irreversible airflow obstruction and is present in airway neutrophils and macrophages. Oncostatin M may link airway inflammation to remodeling in asthma.

Development and characterization of a novel human in vitro blood-nerve barrier model using primary endoneurial endothelial cells

There are phenotypic and functional differences between vascular endothelium from different tissues and between microvascular and macrovascular endothelial cells (ECs) from the same tissue. Relatively little is known about the human blood-nerve barrier (BNB). We report the development of an in vitro BNB model using primary human endoneurial ECs freshly isolated and purified from decedent sciatic nerves via endoneurial stripping, connective tissue enzymatic digestion, and density centrifugation. Primary human endoneurial ECs are spindle shaped and contact inhibited. They rapidly differentiate to form capillary-like networks and microvessels, bind Ulex Europaeus Agglutinin 1 lectin, express von Willebrand factor, and endocytose acetylated low-density lipoprotein. They also express specific transport and cellular adhesion molecules and tight junction proteins, consistent with cells that form a highly restrictive endothelial barrier similar to the blood-brain barrier. When cultured on collagen-coated transwell inserts, the primary human endoneurial ECs develop an in vitro BNB with high transendothelial electrical resistances (160 Omega x cm(2); maximal 12 days after seeding) and low solute permeability coefficient to fluoresceinated high-molecular weight (70 kDa) dextran (2.75 x 10(-3) cm/minute). This in vitro BNB model retains essential known or expected characteristics of the human BNB and has many potential applications for studies of solute, macromolecule, microbial, virus, and leukocyte interactions with this highly specialized endothelial barrier.

Exogenous stromal cell-derived factor-1 induces modest leukocyte recruitment in vivo

Stromal cell-derived factor-1 (SDF-1; CXCL12), a CXC chemokine, has been found to be involved in inflammation models in vivo and in cell adhesion, migration, and chemotaxis in vitro. This study aimed to determine whether exogenous SDF-1 induces leukocyte recruitment in mice. After systemic administration of SDF-1alpha, expression of the adhesion molecules P-selectin and VCAM-1 in mice was measured using a quantitative dual-radiolabeled Ab assay and leukocyte recruitment in various tissues was evaluated using intravital microscopy. The effect of local SDF-1alpha on leukocyte recruitment was also determined in cremaster muscle and compared with the effect of the cytokine TNFalpha and the CXC chemokine keratinocyte-derived chemokine (KC; CXCL1). Systemic administration of SDF-1alpha (10 microg, 4-5 h) induced upregulation of P-selectin, but not VCAM-1, in most tissues in mice. It caused modest leukocyte recruitment responses in microvasculature of cremaster muscle, intestine, and brain, i.e., an increase in flux of rolling leukocytes in cremaster muscle and intestines, leukocyte adhesion in all three tissues, and emigration in cremaster muscle. Local treatment with SDF-1alpha (1 microg, 4-5 h) reduced leukocyte rolling velocity and increased leukocyte adhesion and emigration in cremasteric venules, but the responses were much less profound than those elicited by KC or TNFalpha. SDF-1alpha-induced recruitment was dependent on endothelial P-selectin, but not P-selectin on platelets. We conclude that the exogenous SDF-1alpha enhances leukocyte-endothelial cell interactions and induces modest and endothelial P-selectin-dependent leukocyte recruitment.

A novel mechanism of erythrocyte capture from circulation in humans

OBJECTIVE

The capture of blood cells from the circulation is mediated by highly specialized adhesion molecules. These molecules contribute to the specificity of recruitment for various subsets. Here, we used a simple substrate of hyaluronic acid to investigate the specificity of CD44-mediated recruitment from human whole blood under shear conditions.

MATERIALS AND METHODS

Human whole blood was perfused through a parallel-plate flow chamber, which mimics intravascular conditions. Microscopy was used to directly observe blood-cell interactions with adhesion molecule substrates.

RESULTS

Erythrocytes, but not leukocytes, efficiently tethered to and rolled on the hyaluronic acid substrate. These interactions were demonstrated to be mediated by CD44 and regulated by the sialic acid content of the cells. Inflammatory stimuli did not result in enhanced erythrocyte rolling. Rather, interactions were restricted to aged erythrocytes approaching senescence. This mechanism of erythrocyte capture from the blood flow was found to be restricted to primates and not conserved across mammalian species.

CONCLUSION

This is the first report of erythrocyte tethering and rolling under shear conditions, a behavior, until now, thought to be exclusive to leukocytes. It may represent an important mechanism to identify, capture, and clear old erythrocytes during normal homeostasis or clot formation.

Oncostatin M expression is functionally connected to neutrophils in the early inflammatory phase of skin repair: implications for normal and diabetes-impaired wounds

In this study, we investigated the role of the cytokine oncostatin M (OSM) for wound biology. OSM and its specific OSM receptor subunit beta (OSMRbeta) were induced upon injury. OSM induction paralleled the early influx of polymorphonuclear neutrophils (PMN) into the wound. OSM protein was localized in PMN in very early wounds, whereas OSMRbeta could be detected on macrophages, keratinocytes, and fibroblasts later in repair. To establish a functional connection between PMN and OSM expression in wounds, we depleted mice from circulating PMN by injecting an anti-PMN monoclonal antibody (Ly-6G). PMN-depleted wounds were characterized by a nearly complete loss of OSM but not OSMRbeta mRNA and protein expression within the initial 16-24 hours after injury. PMN-rich chronic wounds from diabetic ob/ob mice were characterized by a strongly elevated OSM mRNA and protein expression as compared to healthy animals. Moreover, a leptin-mediated improvement of chronic wounds in ob/ob mice was paralleled by a complete inhibition of PMN influx associated again with a dramatic loss of OSM expression at the wound site. These data constitute strong evidence that OSM expression during wound inflammation is functionally connected to PMN infiltration.

TNF-alpha-secreting monocytes are recruited into the brain of cholestatic mice

Signaling occurs between the liver and brain in cholestatic liver disease, giving rise to sickness behaviors such as fatigue. However, the signaling pathways involved are poorly defined. Circulating inflammatory mediator levels are increased in cholestasis, leading to speculation that they may be capable of activating circulating immune cells that subsequently could gain access to the brain. Indeed, we have identified that at day 10 after bile duct resection-induced cholestasis, there is activation of circulating monocytes that express tumor necrosis factor alpha (TNF-alpha) in conjunction with increased expression of adhesion molecules by cerebral endothelium. Moreover, using intravital microscopy, we have identified markedly enhanced leukocytes rolling along cerebral endothelial cells, mediated by P-selectin, in bile duct-resected (BDR) but not control mice. In addition, we have identified increased infiltration of monocytes (but not lymphocytes) into the brains of BDR mice and found that these infiltrating monocytes produce TNF-alpha. Furthermore, infiltration of TNF-alpha-secreting monocytes into the brains of cholestatic mice is associated with a broad activation of resident brain macrophages to produce TNF-alpha. In conclusion, cholestasis is associated with an activation of cerebral endothelium that recruits TNF-alpha-producing monocytes into the brain. We hypothesize that enhanced TNF-alpha release within the brain may contribute to the development of cholestasis-associated sickness behaviors, including fatigue.

Breast cancer cells stimulate neutrophils to produce oncostatin M: potential implications for tumor progression

Tumor-associated and tumor-infiltrating neutrophils (TAN) and macrophages (TAM) can account for as much as 50% of the total tumor mass in invasive breast carcinomas. It is thought that tumors secrete factors that elicit a wound-repair response from TAMs and TANs and that this response inadvertently stimulates tumor progression. Oncostatin M is a pleiotropic cytokine belonging to the interleukin-6 family that is expressed by several cell types including activated human T lymphocytes, macrophages, and neutrophils. Whereas oncostatin M can inhibit the proliferation of breast cancer cells in vitro, recent studies suggest that oncostatin M may promote tumor progression by enhancing angiogenesis and metastasis. In addition, neutrophils can be stimulated to synthesize and rapidly release large quantities of oncostatin M. In this article, we show that human neutrophils secrete oncostatin M when cocultured with MDA-MB-231 and T47D human breast cancer cells. Neutrophils isolated from whole blood or breast cancer cells alone express little oncostatin M by immunocytochemistry and ELISA, but neutrophils express and release high levels of oncostatin M when they are cocultured with breast cancer cells. In addition, we show that granulocyte-macrophage colony-stimulating factor produced by breast cancer cells and cell-cell contact are both necessary for the release of oncostatin M from neutrophils. Importantly, neutrophil-derived oncostatin M induces vascular endothelial growth factor from breast cancer cells in coculture and increases breast cancer cell detachment and invasive capacity, suggesting that neutrophils and oncostatin M may promote tumor progression in vivo.

Analysis of gene and protein expression in healthy and carious tooth pulp with cDNA microarray and two-dimensional gel electrophoresis

Complementary DNA (cDNA) microarray and two-dimensional (2-D) gel electrophoresis, combined with mass spectrometry, enable simultaneous analysis of expression patterns of thousands of genes, but their use in pulp biology has been limited. Here we compared gene and protein expression of pulp tissues from sound and carious human teeth using cDNA microarray and 2-D gel electrophoresis to evaluate their usefulness in pulp biology research and to identify the genes with changes in carious teeth. The cDNA microarray revealed several differentially expressed genes and genes with a high expression in both tissues. These genes have various functions, e.g. effects on vascular and nerve structures, inflammation, and cell differentiation. Variability between cDNA hybridizations indicates that the overall gene expression pattern may vary significantly between individual teeth. The 2-D gel electrophoresis revealed no change between healthy and diseased tissue. The identification of 96 proteins in the pulp tissue revealed none of the gene products with corresponding high/different mRNA expression in cDNA microarray. Interestingly, we detected also a hypothetical protein (putative nucleoside diphosphate kinase), and present therefore the first evidence for the existence of this protein. Even though the methods reveal potentially important gene expression, they may currently have only limited value in in vivo pulp biology research.

Secretion of oncostatin M by neutrophils in rheumatoid arthritis

OBJECTIVE

Neutrophils are known to express and release a large number of proinflammatory cytokines when they are stimulated by inflammatory stimuli. The objective of this study was to determine whether neutrophils express oncostatin M (OSM), a member of the interleukin-6 family of cytokines that has been implicated in the pathogenesis of inflammatory joint disease.

METHODS

Neutrophils were isolated from the blood of healthy volunteer donors and from the blood and synovial fluid of patients with rheumatoid arthritis (RA). OSM levels were measured in cell extracts and in culture supernatants by Western blotting. Total RNA was isolated from control and granulocyte-macrophage colony-stimulating factor (GM-CSF)-treated neutrophils, and OSM messenger RNA levels were quantified by hybridization of a radiolabeled probe.

RESULTS

GM-CSF stimulated a rapid and transient expression and release of OSM from blood neutrophils, which was more rapid than the expression and release from blood monocytes. A 28-kd protein was identified in cell extracts, but an additional 25-kd isoform was detected in culture supernatants. Synovial fluid neutrophils could not be stimulated to express OSM, but this cytokine was detected in cell-free supernatants at various levels.

CONCLUSION

Blood neutrophils can be stimulated to express and rapidly release large quantities of OSM. We propose that this important cytokine is released from neutrophils as they infiltrate rheumatoid joints and, thus, contribute to the complex cytokine network that characterizes RA.

Growth plate damage, a feature of juvenile idiopathic arthritis, can be induced by adenoviral gene transfer of oncostatin M: a comparative study in gene-deficient mice

OBJECTIVE

To investigate the involvement of proinflammatory and destructive mediators in oncostatin M (OSM)-induced joint pathology, using gene-deficient mice.

METHODS

An adenoviral vector expressing murine OSM was injected into the joints of naive wild-type mice and mice deficient for interleukin-1 (IL-1), IL-6, tumor necrosis factor alpha (TNFalpha), or inducible nitric oxide synthase (iNOS). Reverse transcription-polymerase chain reaction was used to study gene expression. Inflammation and cartilage proteoglycan (PG) depletion were assessed by histology. OSM and IL-1 levels in synovial fluid from patients with juvenile idiopathic arthritis (JIA) were measured by enzyme-linked immunosorbent assay.

RESULTS

Adenoviral expression of murine OSM led to joint inflammation, bone apposition, chondrophyte formation, articular cartilage PG depletion, and VDIPEN neoepitope expression in wild-type mice. A unique and consistent observation was the focal PG depletion and disorganization of the growth plate cartilage during the first week of inflammation. Synovial IL-1beta, IL-6, TNFalpha, and iNOS gene expression was strongly induced. Of these factors, only deficiency in IL-1 markedly reduced inflammation and PG depletion and completely prevented growth plate damage. In addition, this is the first study in which OSM was detected in JIA synovial fluid. Most samples were also IL-1beta positive.

CONCLUSION

IL-1, but not IL-6, TNFalpha, or iNOS, plays an important role in joint disease induced by intraarticular gene transfer of OSM in mice. The effect of OSM on murine connective tissue and the presence of OSM in human synovial fluid make involvement of OSM in human arthropathies very likely.

Anti-adhesive effect of nitric oxide on Plasmodium falciparum cytoadherence under flow

Nitric oxide (NO) is widely known to inhibit platelet and leukocyte adhesion to endothelium through its regulatory effect on adhesion molecule expression. The objective of the present study was to investigate if NO affects the cytoadherence of Plasmodium falciparum-infected erythrocytes (IRBCs) to human microvascular endothelium (HDMECs) under flow conditions in vitro. The effect of endogenous NO was studied using the NO synthase inhibitor L-N(G)-nitro-arginine-methyl-ester (L-NAME). Treatment of HDMECs with 3 mmol/L of L-NAME for 4 hours significantly enhanced IRBC adhesion and the effect could be reversed by an anti-P-selectin but not an anti-VCAM-1 antibody. The effect of exogenous NO on cytoadherence was studied by using the NO donor 3-(2-hydroxy-2-nitroso-1-propylhydrazino)-1-propanamine (PPN). PPN (300 micro mol/L) treatment reduced the number of adherent IRBCs on resting HDMECs by down-regulating basal ICAM-1 expression, and on tumor necrosis factor-alpha-stimulated HDMECs by inhibition of VCAM-1 induction and down-regulation of ICAM-1 expression. The inhibitory effect of PPN on tumor necrosis factor-alpha-induced VCAM-1 expression at 24 hours was evident when the NO donor was added for as short as 2 hours. These findings suggest that NO may be protective against P. falciparum infection by inhibiting cytoadherence, and underscore the therapeutic potential of NO in the treatment of severe falciparum malaria.

Adenoviral transfer of the murine oncostatin M gene suppresses dextran-sodium sulfate-induced colitis

The use of biologics has promising potential in the treatment of inflammation. Studies with cultured cells and mouse models of disease have ascribed proinflammatory and anti-inflammatory functions to oncostatin M (OSM) and the related cytokine, interleukin-6 (IL-6). Here, we examined the effect of systemic administration of adenoviral (Ad) vectors encoding either murine OSM (AdMuOSM) or murine IL-6 (AdMuIL-6) in a mouse model of colitis. BALB/c mice were treated with a 5-day course of 4% dextran-sodium sulfate (DSS) water with or without administration of adenoviral vectors (i.p. or i.m. at 10(7) plaque-forming units [pfu]) given as a cotreatment or therapy. The deletion variant of the adenovirus served as a control for adenoviral infection. Colitis was assessed by (1) morphology (damage score, macrophage infiltration, apoptosis) and (2) function (myeloperoxidase activity and Ussing chamber analysis of epithelial ion transport). Infection with adenovirus alone did not affect colonic form or function. AdMuOSM (either i.p. or i.m.) significantly reduced the severity of the DSS-induced colitis. There was less damage, reduced macrophage infiltration, fewer apoptotic bodies, and a significant improvement in stimulated ion transport in colonic tissues from the treated mice. No benefit of AdMuIL-6 treatment was observed in this model system. Thus, systemic administration of AdMuOSM given as a cotreatment and to a lesser extent as a therapy was found to be of benefit in DSS-induced colitis, a murine model of inflammatory bowel disease (IBD).