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Cachexia is a wasting syndrome that manifests in more than half of all cancer patients. Cancer-associated cachexia negatively influences the survival of patients and their quality of life. It is characterized by a rapid loss of adipose and skeletal muscle tissues, which is partly mediated by inflammatory cytokines. Here, we explored the crucial roles of interleukin-6 (IL-6) family cytokines, including IL-6, leukemia inhibitory factor, and oncostatin M, in the development of cancer cachexia. These cytokines have been shown to exacerbate cachexia by promoting the wasting of adipose and muscle tissues, activating mechanisms that enhance lipolysis and proteolysis. Overlapping effects of the IL-6 family cytokines depend on janus kinase/signal transducer and activator of transcription 3 signaling. We argue that the blockade of these cytokine pathways individually may fail due to redundancy and future therapeutic approaches should target common downstream elements to yield effective clinical outcomes., (© 2024 The Author(s). The FEBS Journal published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)

Progressive weakness and muscle loss are associated with multiple chronic conditions, including muscular dystrophy and cancer. Cancer-associated cachexia, characterized by dramatic weight loss and fatigue, leads to reduced quality of life and poor survival. Inflammatory cytokines have been implicated in muscle atrophy; however, available anticytokine therapies failed to prevent muscle wasting in cancer patients. Here, we show that oncostatin M (OSM) is a potent inducer of muscle atrophy. OSM triggers cellular atrophy in primary myotubes using the JAK/STAT3 pathway. Identification of OSM targets by RNA sequencing reveals the induction of various muscle atrophy-related genes, including Atrogin1. OSM overexpression in mice causes muscle wasting, whereas muscle-specific deletion of the OSM receptor (OSMR) and the neutralization of circulating OSM preserves muscle mass and function in tumor-bearing mice. Our results indicate that activated OSM/OSMR signaling drives muscle atrophy, and the therapeutic targeting of this pathway may be useful in preventing muscle wasting., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Inflammatory cytokines released by synovium after trauma disturb the gene regulatory network and have been implicated in the pathophysiology of osteoarthritis. A mechanistic understanding of how aging perturbs this process can help identify novel interventions. Here, we introduced network paradigms to simulate cytokine-mediated pathological communication between the synovium and cartilage. Cartilage-specific network analysis of injured young and aged murine knees revealed aberrant matrix remodeling as a transcriptomic response unique to aged knees displaying accelerated cartilage degradation. Next, network-based cytokine inference with pharmacological manipulation uncovered IL6 family member, Oncostatin M (OSM), as a driver of the aberrant matrix remodeling. By implementing a phenotypic drug discovery approach, we identified that the activation of OSM recapitulated an "inflammatory" phenotype of knee osteoarthritis and highlighted high-value targets for drug development and repurposing. These findings offer translational opportunities targeting the inflammation-driven osteoarthritis phenotype., (© 2023 The Authors. Aging Cell published by Anatomical Society and John Wiley & Sons Ltd.)

Purpose of the Review: The bone and hematopoietic tissues coemerge during development and are functionally intertwined throughout mammalian life. Oncostatin M (OSM) is an inflammatory cytokine of the interleukin-6 family produced by osteoblasts, bone marrow macrophages, and neutrophils. OSM acts via two heterodimeric receptors comprising GP130 with either an OSM receptor (OSMR) or a leukemia inhibitory factor receptor (LIFR). OSMR is expressed on osteoblasts, mesenchymal, and endothelial cells and mice deficient for the Osm or Osmr genes have both bone and blood phenotypes illustrating the importance of OSM and OSMR in regulating these two intertwined tissues., Recent Findings: OSM regulates bone mass through signaling via OSMR, adaptor protein SHC1, and transducer STAT3 to both stimulate osteoclast formation and promote osteoblast commitment; the effect on bone formation is also supported by action through LIFR. OSM produced by macrophages is an important inducer of neurogenic heterotopic ossifications in peri-articular muscles following spinal cord injury. OSM produced by neutrophils in the bone marrow induces hematopoietic stem and progenitor cell proliferation in an indirect manner via OSMR expressed by bone marrow stromal and endothelial cells that form hematopoietic stem cell niches. OSM acts as a brake to therapeutic hematopoietic stem cell mobilization in response to G-CSF and CXCR4 antagonist plerixafor. Excessive OSM production by macrophages in the bone marrow is a key contributor to poor hematopoietic stem cell mobilization (mobilopathy) in people with diabetes. OSM and OSMR may also play important roles in the progression of several cancers. It is increasingly clear that OSM plays unique roles in regulating the maintenance and regeneration of bone, hematopoietic stem and progenitor cells, inflammation, and skeletal muscles. Dysregulated OSM production can lead to bone pathologies, defective muscle repair and formation of heterotopic ossifications in injured muscles, suboptimal mobilization of hematopoietic stem cells, exacerbated inflammatory responses, and anti-tumoral immunity. Ongoing research will establish whether neutralizing antibodies or cytokine traps may be useful to correct pathologies associated with excessive OSM production., (© 2024. The Author(s).)

Age-associated clonal hematopoiesis (CH) occurs due to somatic mutations accrued in hematopoietic stem cells (HSCs) that confer a selective growth advantage in the context of aging. The mechanisms by which CH-mutant HSCs gain this advantage with aging are not comprehensively understood. Using unbiased transcriptomic approaches, we identified Oncostatin M (OSM) signaling as a candidate contributor to age-related Dnmt3a-mutant CH. We found that Dnmt3a-mutant HSCs from young adult mice (3-6 months old) subjected to acute OSM stimulation do not demonstrate altered proliferation, apoptosis, hematopoietic engraftment, or myeloid differentiation. Dnmt3a-mutant HSCs from young mice do transcriptionally upregulate an inflammatory cytokine network in response to acute in vitro OSM stimulation as evidenced by significant upregulation of the genes encoding IL-6, IL-1β, and TNFα. OSM-stimulated Dnmt3a-mutant HSCs also demonstrate upregulation of the anti-inflammatory genes Socs3, Atf3, and Nr4a1. In the context of an aged bone marrow (BM) microenvironment, Dnmt3a-mutant HSCs upregulate proinflammatory genes but not the anti-inflammatory genes Socs3, Atf3, and Nr4a1. The results from our studies suggest that aging may exhaust the regulatory mechanisms that HSCs employ to resolve inflammatory states in response to factors such as OSM., Competing Interests: Conflict of Interest Disclosure J.J.T. has received research support from H3 Biomedicine, Inc., and patent royalties from Fate Therapeutics. All other authors declare no competing interests., (Copyright © 2023 ISEH -- Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.)

Purpose: Radiation-induced heart fibrosis (RIHF) is a severe consequence of radiation-induced heart damage (RIHD) leading to impaired cardiac function. The involvement of oncostatin M (OSM) and its receptor (OSMR) in RIHD remains unclear. This study aimed to investigate the specific mechanism of OSM/OSMR in RIHF/RIHD., Methods and Materials: RNA sequencing was performed on heart tissues from a RIHD mouse model. OSM levels were assessed in serum samples obtained from patients receiving thoracic radiation therapy (RT), as well as in RIHF mouse heart tissues and serum using enzyme-linked immunosorbent assay. Fiber activation was evaluated through costimulation of primary cardiac fibroblasts and NIH3T3 cells with RT and OSM, using Western blotting, immunofluorescence, and quantitative Polymerase Chain Reaction (qPCR). Adeno-associated virus serotype 9-mediated overexpression or silencing of OSM specifically in the heart was performed in vivo to assess cardiac fibrosis levels by transthoracic echocardiography and pathologic examination. The regulatory mechanism of OSM on the transcription level of SMAD4 was further explored in vitro using mass spectrometric analysis, chromatin immunoprecipitation-qPCR, and DNA pull-down., Results: OSM levels were elevated in the serum of patients after thoracic RT as well as in RIHF mouse cardiac endothelial cells and mouse serum. The OSM rate (post-RT/pre-RT) and the heart exposure dose in RT patients showed a positive correlation. Silencing OSMR in RIHF mice reduced fibrosis, while OSMR overexpression increased fibrotic responses. Furthermore, increased OSM promoted histone acetylation (H3K27ac) in the SMAD4 promoter region, influencing SMAD4 transcription and subsequently enhancing fibrotic response., Conclusions: The findings demonstrated that OSM/OSMR signaling promotes SMAD4 transcription in cardiac fibroblasts through H3K27 hyperacetylation, thereby promoting radiation-induced cardiac fibrosis and manifestations of RIHD., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Atherosclerosis is a multifactorial inflammatory disease characterized by the development of plaque formation leading to occlusion of the vessel and hypoxia of the tissue supplied by the vessel. Chronic inflammation and altered collagen expression render stable plaque to unstable and increase plaque vulnerability. Thinned and weakened fibrous cap results in plaque rupture and formation of thrombosis and emboli formation leading to acute ischemic events such as stroke and myocardial infarction. Inflammatory mediators including TREM-1, TLRs, MMPs, and immune cells play a critical role in plaque vulnerability. Among the other inflammatory mediators, oncostatin-M (OSM), a pro-inflammatory cytokine, play an important role in the development and progression of atherosclerosis, however, the role of OSM in plaque vulnerability and extracellular matrix remodeling (ECM) is not well understood and studied. Since ECM remodeling plays an important role in atherosclerosis and plaque vulnerability, a detailed investigation on the role of OSM in ECM remodeling and plaque vulnerability is critical. This is important because the role of OSM has been discussed in the context of proliferation of vascular smooth muscle cells and regulation of cytokine expression but the role of OSM is scarcely discussed in relation to ECM remodeling and plaque vulnerability. This review focuses on critically discussing the role of OSM in ECM remodeling and plaque vulnerability., (© 2023. The Author(s).)

Differential regulation of a gene having either canonical or non-canonical cyclic AMP response element (CRE) in its promoter is primarily accomplished by its interactions with CREB (cAMP-response element binding protein). The present study aims to delineate the mechanism of the CREB-CRE interactions at the Oncostatin-M (osm) promoter by in vitro and in silico approaches. The non-canonical CRE osm consists of two half-CREs separated by a short intervening sequence of 9 base pairs. In this study, in vitro binding assays revealed that out of the two CRE half-sites, the right half-CRE was indispensable for binding of CREB, while the left sequence showed weaker binding ability and specificity. Genome-wide modeling and high throughput free energy calculations for the energy-minimized models containing CREB-CRE osm revealed that there was no difference in the binding of CREB to the right half of CRE osm site when compared to the entire CRE osm . These results were in accordance with the in vitro studies, confirming the indispensable role of the right half-CRE osm site in stable complex formation with the CREB protein. Additionally, conversion of the right half-CRE osm site to a canonical CRE palindrome showed stronger CREB binding, irrespective of the presence or absence of the left CRE sequence. Thus, the present study establishes an interesting insight into the interaction of CREB with a CRE variant located at the far end of a TATA-less promoter of a cytokine-encoding gene, which in turn could be involved in the regulation of transcription under specific conditions., Competing Interests: Declaration of competing interest No conflict of interest., (Copyright © 2023. Published by Elsevier B.V.)

Background: Oncostatin M (OSM) is a secreted cytokine of the interleukin (IL)-6 family that induces biological effects by activating functional receptor complexes of the common signal transducing component glycoprotein 130 (gp130) and OSM receptor β (OSMR) or leukaemia inhibitory factor receptor (LIFR), which are mainly involved in chronic inflammatory and cardiovascular diseases. The effect and underlying mechanism of OSM/OSMR/LIFR on the development of cardiac hypertrophy remains unclear., Methods and Results: OSMR-knockout (OSMR-KO) mice were subjected to aortic banding (AB) surgery to establish a model of pressure overload-induced cardiac hypertrophy. Echocardiographic, histological, biochemical and immunological analyses of the myocardium and the adoptive transfer of bone marrow-derived macrophages (BMDMs) were conducted for in vivo studies. BMDMs were isolated and stimulated with lipopolysaccharide (LPS) for the in vitro study. OSMR deficiency aggravated cardiac hypertrophy, fibrotic remodelling and cardiac dysfunction after AB surgery in mice. Mechanistically, the loss of OSMR activated OSM/LIFR/STAT3 signalling and promoted a proresolving macrophage phenotype that exacerbated inflammation and impaired cardiac repair during remodelling. In addition, adoptive transfer of OSMR-KO BMDMs to WT mice after AB surgery resulted in a consistent hypertrophic phenotype. Moreover, knockdown of LIFR in myocardial tissue with Ad-shLIFR ameliorated the effects of OSMR deletion on the phenotype and STAT3 activation., Conclusions: OSMR deficiency aggravated pressure overload-induced cardiac hypertrophy by modulating macrophages and OSM/LIFR/STAT3 signalling, which provided evidence that OSMR might be an attractive target for treating pathological cardiac hypertrophy and heart failure., (© 2023. The Author(s).)

Innate immune cells infiltrate growing adipose tissue and propagate inflammatory clues to metabolically distant tissues, thereby promoting glucose intolerance and insulin resistance. Cytokines of the IL-6 family and gp130 ligands are among such signals. The role played by oncostatin M (OSM) in the metabolic consequences of overfeeding is debated, at least in part, because prior studies did not distinguish OSM sources and dynamics. Here, we explored the role of OSM in metabolic responses and used bone marrow transplantation to test the hypothesis that hematopoietic cells are major contributors to the metabolic effects of OSM. We show that OSM is required to adapt during the development of obesity because OSM concentrations are dynamically modulated during high-fat diet (HFD) and Osm-/- mice displayed early-onset glucose intolerance, impaired muscle glucose uptake, and worsened liver inflammation and damage. We found that OSM is mostly produced by blood cells and deletion of OSM in hematopoietic cells phenocopied glucose intolerance of whole-body Osm-/- mice fed a HFD and recapitulated liver damage with increased aminotransferase levels. We thus uncovered that modulation of OSM is involved in the metabolic response to overfeeding and that hematopoietic cell-derived OSM can regulate metabolism, likely via multiple effects in different tissues., (© 2023 by the American Diabetes Association.)

Crosstalk between muscle fibers and immune cells is well known in the processes of muscle repair after exercise, especially resistance exercise. In aerobic exercise, however, this crosstalk is not fully understood. In the present study, we found that macrophages, especially anti-inflammatory (M2) macrophages, and neutrophils accumulated in skeletal muscles of mice 24 h after a single bout of an aerobic exercise. The expression of oncostatin M (OSM), a member of the interleukin 6 family of cytokines, was also increased in muscle fibers immediately after the exercise. In addition, we determined that deficiency of OSM in mice inhibited the exercise-induced accumulation of M2 macrophages and neutrophils, whereas intramuscular injection of OSM increased these immune cells in skeletal muscles. Furthermore, the chemokines related to the recruitment of macrophages and neutrophils were induced in skeletal muscles after aerobic exercise, which were attenuated in OSM-deficient mice. Among them, CC chemokine ligand 2, CC chemokine ligand 7, and CXC chemokine ligand 1 were induced by OSM in skeletal muscles. Next, we analyzed the direct effects of OSM on the skeletal muscle macrophages, because the OSM receptor β subunit was expressed predominantly in macrophages in the skeletal muscle. OSM directly induced the expression of these chemokines and anti-inflammatory markers in the skeletal muscle macrophages. From these findings, we conclude that OSM is essential for aerobic exercise-induced accumulation of M2 macrophages and neutrophils in the skeletal muscle partly through the regulation of chemokine expression in macrophages., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

The tumor microenvironment (TME) is reprogrammed by cancer cells and participates in all stages of tumor progression. The contribution of stromal cells to the reprogramming of the TME is not well understood. Here, we provide evidence of the role of the cytokine oncostatin M (OSM) as central node for multicellular interactions between immune and nonimmune stromal cells and the epithelial cancer cell compartment. OSM receptor (OSMR) deletion in a multistage breast cancer model halted tumor progression. We ascribed causality to the stromal function of the OSM axis by demonstrating reduced tumor burden of syngeneic tumors implanted in mice lacking OSMR. Single-cell and bioinformatic analysis of murine and human breast tumors revealed that OSM expression was restricted to myeloid cells, whereas OSMR was detected predominantly in fibroblasts and, to a lower extent, cancer cells. Myeloid-derived OSM reprogrammed fibroblasts to a more contractile and tumorigenic phenotype and elicited the secretion of VEGF and proinflammatory chemokines CXCL1 and CXCL16, leading to increased myeloid cell recruitment. Collectively, our data support the notion that the stromal OSM/OSMR axis reprograms the immune and nonimmune microenvironment and plays a key role in breast cancer progression.

The inhibitor of growth family member 4 (ING4) is one of the ING family genes, serves as a repressor of angiogenesis or tumour growth and suppresses loss of contact inhibition. Oncostatin M (OSM) is a multifunctional cytokine that belongs to the interleukin (IL)-6 subfamily with several biological activities. However, the role of recombinant adenoviruses co-expressing ING4 and OSM (Ad-ING4-OSM) in anti-tumour activity of laryngeal cancer has not yet been identified. Recombinant Ad-ING4-OSM was used to evaluate their combined effect on enhanced anti-tumour activity in Hep-2 cells of laryngeal cancer in vivo. Moreover, in vitro function assays of co-expression of Ad-ING4-OSM were performed to explore impact of co-expression of Ad-ING4-OSM on biological phenotype of laryngeal cancer cell line, that is Hep-2 cells. In vitro, Ad-ING4-OSM significantly inhibited the growth, enhanced apoptosis, altered cell cycle with G1 and G2/M phase arrest, and upregulated the expression of P21, P27, P53 and downregulated survivin in laryngeal cancer Hep-2 cells. Furthermore, in vivo functional experiments of co-expressing of Ad-ING4-OSM demonstrated that solid tumours in the nude mouse model were significantly suppressed, and the co-expressing Ad-ING4-OSM showed a significant upregulation expression of P21, P53, Bax and Caspase-3 and a downregulation of Cox-2, Bcl-2 and CD34. This study for the first time demonstrated the clinical value and the role of co-expressing Ad-ING4-OSM in biological function of laryngeal cancer. This work suggested that co-expressing Ad-ING4-OSM might serve as a potential therapeutic target for laryngeal cancer patients., (© 2022 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

Cellular signaling responses show substantial cell-to-cell heterogeneity, which is often ascribed to the inherent randomness of biochemical reactions, termed molecular noise, wherein high noise implies low signaling fidelity. Alternatively, heterogeneity could arise from differences in molecular content between cells, termed molecular phenotypic variability, which does not necessarily imply imprecise signaling. The contribution of these two processes to signaling heterogeneity is unclear. Here, we fused fibroblasts to produce binuclear syncytia to distinguish noise from phenotypic variability in the analysis of cytokine signaling. We reasoned that the responses of the two nuclei within one syncytium could approximate the signaling outcomes of two cells with the same molecular content, thereby disclosing noise contribution, whereas comparison of different syncytia should reveal contribution of phenotypic variability. We found that ~90% of the variance in the primary response (which was the abundance of phosphorylated, nuclear STAT) to stimulation with the cytokines interferon-γ and oncostatin M resulted from differences in the molecular content of individual cells. Thus, our data reveal that cytokine signaling in the system used here operates in a reproducible, high-fidelity manner.

Exacerbations of symptoms represent an unmet need for people with asthma. Bacterial dysbiosis and opportunistic bacterial infections have been observed in, and may contribute to, more severe asthma. However, the molecular mechanisms driving these exacerbations remain unclear. We show here that bacterial lipopolysaccharide (LPS) induces oncostatin M (OSM) and that airway biopsies from patients with severe asthma present with an OSM-driven transcriptional profile. This profile correlates with activation of inflammatory and mucus-producing pathways. Using primary human lung tissue or human epithelial and mesenchymal cells, we demonstrate that OSM is necessary and sufficient to drive pathophysiological features observed in severe asthma after exposure to LPS or Klebsiella pneumoniae . These findings were further supported through blockade of OSM with an OSM-specific antibody. Single-cell RNA sequencing from human lung biopsies identified macrophages as a source of OSM. Additional studies using Osm -deficient murine macrophages demonstrated that macrophage-derived OSM translates LPS signals into asthma-associated pathologies. Together, these data provide rationale for inhibiting OSM to prevent bacterial-associated progression and exacerbation of severe asthma.

Oncostatin M (OSM) plays a role in various inflammatory reactions, and neutrophils are the main source of OSM in pulmonary diseases. However, there is no evidence showing the mechanism of OSM production in neutrophils. While dexamethasone (Dex) has been known to exert anti-inflammatory activity in various fields, the precise mechanisms of OSM downregulation by Dex in neutrophils remain to be determined. Here, we examined how OSM is produced in neutrophil-like differentiated HL-60 cells. Enzyme-linked immunosorbent assay, real-time polymerase chain reaction, and Western blot analysis were utilized to assess the potential of Dex. Granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulation resulted in OSM elevation in neutrophil-like dHL-60 cells. OSM elevation induced by GM-CSF is regulated by phosphatidylinositol 3-kinase (PI3K)/Akt/nuclear factor (NF)-kB signal cascades. GM-CSF stimulation upregulated phosphorylated levels of PI3K or Akt or NF-κB in neutrophil-like dHL-60 cells. Treatment with Dex decreased OSM levels as well as the phosphorylated levels of PI3K or Akt or NF-κB in neutrophil-like dHL-60 cells. Our findings show the potential of Dex in the treatment of inflammatory diseases via blocking of OSM.

Objective: Obesity is associated with low-grade adipose tissue inflammation and locally elevated levels of several glycoprotein 130 (gp130) cytokines. The conversion of white into brown-like adipocytes (browning) may increase energy expenditure and revert the positive energy balance that underlies obesity. Although different gp130 cytokines and their downstream targets were shown to regulate expression of the key browning marker uncoupling protein 1 (Ucp1), it remains largely unknown how this contributes to the development and maintenance of obesity. Herein, we aim to study the role of gp130 cytokine signaling in white adipose tissue (WAT) browning in the obese state., Methods: Protein and gene expression levels of UCP1 and other thermogenic markers were assessed in a subcutaneous adipocyte cell line, adipose tissue depots from control or adipocyte-specific gp130 knockout (gp130 Δadipo ) mice fed either chow or a high-fat diet (HFD), or subcutaneous WAT biopsies from a human cohort of lean and obese subjects. WAT browning was modeled in vitro by exposing mature adipocytes to isoproterenol after stimulation with gp130 cytokines. ERK and JAK-STAT signaling were blocked using the inhibitors U0126 and Tofacitinib, respectively., Results: Inguinal WAT of HFD-fed gp130 Δadipo mice exhibited significantly elevated levels of UCP1 and other browning markers such as Cidea and Pgc-1α. In vitro, treatment with the gp130 cytokine oncostatin M (OSM) lowered isoproterenol-induced UCP1 protein and gene expression levels in a dose-dependent manner. Mechanistically, OSM mediated the inhibition of Ucp1 via the JAK-STAT but not the ERK pathway. As with mouse data, OSM gene expression in human WAT positively correlated with BMI (r = 0.284, p = 0.021, n = 66) and negatively with UCP1 expression (r = -0.413, p < 0.001, n = 66)., Conclusions: Our data support the notion that OSM negatively regulates thermogenesis in WAT and thus may be an attractive target for treating obesity., (Copyright © 2021 The Author(s). Published by Elsevier GmbH.. All rights reserved.)

Although patients with advanced ovarian cancer may respond initially to treatment, disease relapse is common, and nearly 50% of patients do not survive beyond five years, indicating an urgent need for improved therapies. To identify new therapeutic targets, we performed single-cell and nuclear RNA-seq data set analyses on 17 human ovarian cancer specimens, revealing the oncostatin M receptor (OSMR) as highly expressed in ovarian cancer cells. Conversely, oncostatin M (OSM), the ligand of OSMR, was highly expressed by tumor-associated macrophages and promoted proliferation and metastasis in cancer cells. Ovarian cancer cell lines and additional patient samples also exhibited elevated levels of OSMR when compared with other cell types in the tumor microenvironment or to normal ovarian tissue samples. OSMR was found to be important for ovarian cancer cell proliferation and migration. Binding of OSM to OSMR caused OSMR-IL6ST dimerization, which is required to produce oncogenic signaling cues for prolonged STAT3 activation. Human monoclonal antibody clones B14 and B21 directed to the extracellular domain of OSMR abrogated OSM-induced OSMR-IL6ST heterodimerization, promoted the internalization and degradation of OSMR, and effectively blocked OSMR-mediated signaling in vitro . Importantly, these antibody clones inhibited the growth of ovarian cancer cells in vitro and in vivo by suppressing oncogenic signaling through OSMR and STAT3 activation. Collectively, this study provides a proof of principle that anti-OSMR antibody can mediate disruption of OSM-induced OSMR-IL6ST dimerization and oncogenic signaling, thus documenting the preclinical therapeutic efficacy of human OSMR antagonist antibodies for immunotherapy in ovarian cancer. SIGNIFICANCE: This study uncovers a role for OSMR in promoting ovarian cancer cell proliferation and metastasis by activating STAT3 signaling and demonstrates the preclinical efficacy of antibody-based OSMR targeting for ovarian cancer treatment., (©2021 American Association for Cancer Research.)

Clear-cell renal cell carcinoma (ccRCC) is the most prevalent subtype of renal cell carcinoma (RCC), and its progression has been linked to chronic inflammation. About 70% of the ccRCC cases are associated with inactivation of the von Hippel-Lindau ( VHL ) tumor-suppressor gene. However, it is still not clear how mutations in VHL , encoding the substrate-recognition subunit of an E3 ubiquitin ligase that targets the alpha subunit of hypoxia-inducible factor-α (HIFα), can coordinate tissue inflammation and tumorigenesis. We previously generated mice with conditional Vhlh knockout in kidney tubules, which resulted in severe inflammation and fibrosis in addition to hyperplasia and the appearance of transformed clear cells. Interestingly, the endothelial cells (EC), although not subject to genetic manipulation, nonetheless showed profound changes in gene expression that suggest a role in promoting inflammation and tumorigenesis. Oncostatin M (OSM) mediated the interaction between VHL -deficient renal tubule cells and the ECs, and the activated ECs in turn induced macrophage recruitment and polarization. The OSM-dependent microenvironment also promoted metastasis of exogenous tumors. Thus, OSM signaling initiates reconstitution of an inflammatory and tumorigenic microenvironment by VHL -deficient renal tubule cells, which plays a critical role in ccRCC initiation and progression. SIGNIFICANCE: A novel mechanism of cross-talk between ECs and VHL -deficient kidney tubules that stimulates inflammation and tumorigenesis is discovered, suggesting OSM could be a potential target for ccRCC intervention., (©2021 The Authors; Published by the American Association for Cancer Research.)

Objectives: This study aimed to determine whether mRNA expression of oncostatin-M (OSM) and its receptor (OSMR) in initial, pre-treatment intestinal biopsies is predictive of response to tumor necrosis factor antagonists (anti-TNF) in a pediatric inflammatory bowel disease (IBD) cohort. Secondary outcomes correlated OSM and OSMR expression with demographic variables; IBD type, extent, phenotype, and severity; laboratory values; and endoscopic findings., Methods: A retrospective chart review was conducted on 98 pediatric patients. Patients' clinical courses were stratified as follows: failed anti-TNF (n = 14), quiescent on anti-TNF (n = 36), anti-TNF naïve (n = 19), and age-matched non-IBD controls (n = 29). The mRNA from each patient's pre-treatment ileal or colonic biopsy was isolated, and expression of OSM and OSMR was analyzed., Results: There was no difference in OSM or OSMR expression among the three IBD groups; however, expression was significantly higher in patients with IBD than non-IBD controls (P < 0.001). OSM and OSMR were more highly expressed in patients with ulcerative colitis (UC) with a Mayo score of 3 (P = 0.0092 and P = 0.0313, respectively). High OSM expression correlated with severe disease activity indices at diagnosis (P = 0.002), anemia at diagnosis (P = 0.0236), and need for immunomodulators (P = 0.0193) and steroids (P = 0.0273) during patients' clinical courses., Conclusions: OSM and OSMR expression were not predictive of response to anti-TNF in our pediatric cohort. OSM expression did correlate with IBD compared with healthy controls as well as with several clinical indicators of severe IBD., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 by European Society for Pediatric Gastroenterology, Hepatology, and Nutrition and North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition.)

Psoriasis is a chronic disorder characterized by a complex interplay between keratinocytes and inflammatory mediators. In a previous study, we evaluated diacerein's ability to diminish interleukin (IL)-1's proinflammatory effects on cultured primary human keratinocytes. In this study, we evaluated diacerein's ability to diminish the inflammatory effects of a cytokine mixture (CM) consisting of IL-17A, IL-22, oncostatin M, IL-1A, and tumor necrosis factor (TNF)-alpha on cultured primary human keratinocytes. These five cytokines have been previously shown to induce an in vivo -equivalent cell culture psoriasis model. We also evaluated diacerein's anti-inflammatory effects in comparison to and in combination with infliximab, a TNF-alpha inhibitor currently used in the treatment of psoriasis. We found 81 genes that were significantly ( P  < 0.05) dysregulated by CM compared to medium control. All three treatment groups (diacerein alone, infliximab alone, and diacerein plus infliximab) diminished the effects of CM on these genes, with the greatest effect seen with diacerein plus infliximab. Using enzyme-linked immunosorbent assay method on cell culture supernatant, we determined the protein concentration for five genes (IL-19, IL-6, CSF3, S100A8, and NAP-2) significantly ( P  < 0.05) upregulated by CM at the gene level. Diacerein alone diminished the effect of CM on the protein concentration of two genes, whereas diacerein plus infliximab diminished the effect of CM on the protein concentration of all the five genes. Based on these results, we conclude that diacerein alone or in combination with infliximab may have a therapeutic role in psoriasis by downregulating key inflammatory mediators.

Our previous study indicated knockout of receptor for advanced glycation end-products (RAGE) significantly attenuated cigarette smoke (CS)-induced airway inflammation in mice. In the present study, we aim to further detect the mediatory effects of RAGE in DNA methylated modification in CS-induced airway inflammation. Lung tissues from the CS-exposed mouse model of airway inflammation were collected for profiling of DNA methylation by liquid hybridization capture-based bisulfite sequencing, which were used for conjoint analysis with our previous data of gene expression by cDNA microarray to identify functional methylated genes, as well as hub genes selected by protein-protein interaction (PPI) network analysis, and functional enrichment analyses were then performed. After RAGE knockout, 90 genes were identified by intersection of the differentially methylated genes and differentially expressed genes. According to the reversed effects of methylation in promoters on gene transcription, 14 genes with functional methylated modification were further identified, among which chemokine (C-X-C motif) ligand 1 (CXCL1), Toll-like receptor 6 (TLR6) and oncostatin M (OSM) with hypomethylation in promoters, were selected as the hub genes by PPI network analysis. Moreover, functional enrichment analyses showed the 14 functional methylated genes, including the 3 hub genes, were mainly enriched in immune-inflammatory responses, especially mitogen-activated protein kinase, tumor necrosis factor, TLRs, interleukin (IL)-6 and IL-17 pathways. The present study suggests that RAGE mediates functional DNA methylated modification in a cluster of 14 targeted genes, particularly hypomethylation in promoters of CXCL1, TLR6 and OSM, which might significantly contribute to CS-induced airway inflammation via a network of signaling pathways., (© 2021 The Author(s).)

Long noncoding RNAs play key roles in several cancers, but their potential functions in gastroenteropancreatic neuroendocrine neoplasms remain to be investigated. We performed GeneChip assay to explore differentiated lncRNAs in gastric NENs and peri-cancerous tissues. The regulation of HNF1A-AS1 on biological behavior of GEP-NENs cells and in vivo xenograft model was confirmed by CCK8, colony formation assay, transwell, western blot and qRT-PCR. We next detected the potential transcription factors and the binding sites between them with bioinformatic analysis. qRT-PCR was performed to analyze the exact relationship between them. HNF1A-AS1 expression was decreased in gastric NENs tissues ( p < 0.01). Over-expression of HNF1A-AS1 suppressed cellular proliferation, migration and invasion. Knockdown of transcription factor 3 inhibited the expression of HNF1A-AS1 and promoted cellular migration and invasion. Oncostatin M was identified as the downstream target of HNF1A-AS1. Inhibition of transforming growth factor-β activity inhibited HNF1A-AS1/Oncostatin M-mediated epithelial-mesenchymal transition. Our data suggest that transcription factor 3/HNF1A-AS1/Oncostatin M axis inhibits the tumorigenesis and metastasis of gastroenteropancreatic neuroendocrine neoplasms via transforming growth factor-β signaling.

Background: Invasive ductal carcinoma (IDC) is a serious problem for patients as it metastasizes, decreasing 5-year patient survival from > 95 to ~ 27%. The breast tumor microenvironment (TME) is often saturated with proinflammatory cytokines, such as oncostatin M (OSM), which promote epithelial-to-mesenchymal transitions (EMT) in IDC and increased metastasis. The extracellular matrix (ECM) also plays an important role in promoting invasive and metastatic potential of IDC. Specifically, the reorganization and alignment of collagen fibers in stromal ECM leads to directed tumor cell motility, which promotes metastasis. Lysyl oxidase like-2 (LOXL2) catalyzes ECM remodeling by crosslinking of collagen I in the ECM. We propose a novel mechanism whereby OSM induces LOXL2 expression, mediating stromal ECM remodeling of the breast TME., Methods: Bioinformatics was utilized to determine survival and gene correlation in patients. IDC cell lines were treated with OSM (also IL-6, LIF, and IL-1β) and analyzed for LOXL2 expression by qRT-PCR and immunolabelling techniques. Collagen I contraction assays, 3D invasion assays, and confocal microscopy were performed with and without LOXL2 inhibition to determine the impact of OSM-induced LOXL2 on the ECM., Results: Our studies demonstrate that IDC patients with high LOXL2 and OSM co-expression had worse rates of metastasis-free survival than those with high levels of either, individually, and LOXL2 expression is positively correlated to OSM/OSM receptor (OSMR) expression in IDC patients. Furthermore, human IDC cells treated with OSM resulted in a significant increase in LOXL2 mRNA, which led to upregulated protein expression of secreted, glycosylated, and enzymatically active LOXL2. The expression of LOXL2 in IDC cells did not affect OSM-promoted EMT, and LOXL2 was localized to the cytoplasm and/or secreted. OSM-induced LOXL2 promoted an increase in ECM collagen I fiber crosslinking, which led to significant fiber alignment between cells and increased IDC cell invasion., Conclusions: Aligned collagen fibers in the ECM provide pathways for tumor cells to migrate more easily through the stroma to nearby vasculature and tissue. These results provide a new paradigm through which proinflammatory cytokine OSM promotes tumor progression. Understanding the nuances in IDC metastasis will lead to better potential therapeutics to combat against the possibility.

Background: Despite progress in the detection of biological molecules that contribute to intracranial aneurysm (IA) development, many pathophysiological mechanisms remain unclear, particularly with regard to predicting IA rupture. In this study, we aimed to identify hub genes and construct a new model to predict IA rupture., Methods: Four datasets (62 ruptured IAs, 16 unruptured IAs, and 31 normal controls) were downloaded from the Gene Expression Omnibus. Differentially expressed genes (DEGs) were identified between the IAs and normal controls. All overlapping genes were analyzed using weighted gene co-expression network analysis. Functional enrichment analyses were performed using key modules. We then intersected the key module genes with DEGs. Protein-protein interaction networks were assessed to identify key hub genes. Least absolute shrinkage and selection operator logistic regression analysis was performed to construct a prediction model. A receiver operating characteristic curve was constructed to evaluate the reliability of the scoring system., Results: After intersection and normalization, 433 DEGs were identified and 15,388 genes were selected for weighted gene co-expression network analysis. The black module with 1145 genes exhibited the highest correlation with IA rupture. Many potential mechanisms are involved, such as the inflammatory response, innate immune response, extracellular exosome, and extracellular space. Thirty hub genes were selected from the protein-protein interaction, and 4 independent risk genes, TNFAIP6, NCF2, OSM, and IRAK3, were identified in the least absolute shrinkage and selection operator logistic regression model., Conclusions: Our prediction model not only serves as a useful tool for assessing the risk of IA rupture, but the key genes identified herein could also serve as biomarkers and therapeutic targets., (Copyright © 2021. Published by Elsevier Inc.)

Pathologic roles of innate immunity in neurologic disorders are well described, but their beneficial aspects are less understood. Dectin-1, a C-type lectin receptor (CLR), is largely known to induce inflammation. Here, we report that Dectin-1 limited experimental autoimmune encephalomyelitis (EAE), while its downstream signaling molecule, Card9, promoted the disease. Myeloid cells mediated the pro-resolution function of Dectin-1 in EAE with enhanced gene expression of the neuroprotective molecule, Oncostatin M (Osm), through a Card9-independent pathway, mediated by the transcription factor NFAT. Furthermore, we find that the Osm receptor (OsmR) functioned specifically in astrocytes to reduce EAE severity. Notably, Dectin-1 did not respond to heat-killed Mycobacteria, an adjuvant to induce EAE. Instead, endogenous Dectin-1 ligands, including galectin-9, in the central nervous system (CNS) were involved to limit EAE. Our study reveals a mechanism of beneficial myeloid cell-astrocyte crosstalk regulated by a Dectin-1 pathway and identifies potential therapeutic targets for autoimmune neuroinflammation., Competing Interests: Declaration of Interests R.-R.J. is a consultant of Boston Scientific and received a research grant from the company. This activity is not related to the current study. The remaining authors declare no competing interests., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Feiyangchangweiyan capsule (FYC) is a traditional Chinese medicine formulation used in the clinical treatment of acute and chronic gastroenteritis and bacterial dysentery. However, the effect of FYC on ulcerative colitis (UC) and the mechanism thereof remains unknown., Purpose: To investigate the protective effect of FYC on UC mice induced by dextran sulfate sodium and illustrate the potential mechanism of this effect., Methods: Here, we established a model of UC mice by dextran sulfate sodium and administered with FYC. The disease activity index (DAI), colon length, myeloperoxidase (MPO) content in serum, pathological structure and ultrastructural changes, and inflammatory cell infiltration of colon tissue were evaluated. Transcriptome and 16S rDNA sequencing were employed to illuminate the mechanism of FYC in the protection of UC mice., Results: FYC significantly alleviates the pathological damage and the infiltration of inflammatory cells in colon tissue of dextran sulfate sodium induced UC mice, rescues shortened colon length, reduces DAI score, MPO content in serum, and pro-inflammatory factors including IL-1β, IL-6, CCL11, MCP-1 and MIP-2, and increases anti-inflammatory factors such as IL-10. Transcriptomics revealed that Oncostatin M (OSM) and its receptor (OSMR) are the critical pathway for UC treatment by FYC. OSM and OSMR increased in UC mice compared to control mice, and decreased with FYC, which was verified via measurement of OSM and OSMR mRNA and protein levels. Furthermore, we observed that FYC modulates intestinal microbiome composition (e.g., the proportion of Barnesiella/Proteobacteria) by affecting the inflammatory factors., Conclusion: FYC exerts an effect on UC by inhibiting the OSM/OSMR pathway and regulating inflammatory factors to improve the intestinal flora., (Copyright © 2020. Published by Elsevier GmbH.)

Purpose: Vernal keratoconjunctivitis (VKC) is a severe and recurrent allergic conjunctivitis, the mechanism of which is not well understood. In this study, we investigated the role of oncostatin M (OSM) in the pathogenesis of VKC, with a focus on tissue remodeling., Study Design: Clinical and experimental., Patients and Methods: The OSM concentrations in tear fluid samples obtained from VKC patients and healthy controls were measured using ELISA, and the expression of OSM mRNA and protein in giant papillae resected from VKC patients was investigated using RT-PCR and immunohistochemistry, respectively. In cultured human conjunctival epithelial cells (HconEpiCs), expression of OSM receptor β (OSMRβ) was detected using immunocytochemical and FACS analyses. Finally, we investigated whether recombinant OSM activated STAT1 and STAT3 to induce the expression of various genes related to tissue remodeling in HconEpiCs, by using Western blot analysis, microarray analysis, and RT-PCR., Results: The OSM concentration was higher in the tear fluid of VKC patients than in that of the healthy controls, and strong expression of OSM mRNA was found in the giant papillae. We also detected T cells expressing OSM in the giant papillae. In addition, HconEpiCs showed surface expression of OSMRβ. Recombinant human OSM strongly activated both STAT1 and STAT3 in HconEpiCs and induced various tissue remodeling-related genes, including MMP-1, MMP-3, IL-24, IL-20, serpinB3, S100A7, tenascin C, and SOCS3., Conclusion: Our results suggest that OSM is one of the key molecules involved in remodeling of giant papillae in VKC.

Cutaneous squamous cell carcinoma (cuSCC) is the second most common skin cancer and commonly arises in chronically UV-exposed skin or chronic wounds. Since UV exposure and chronic wounds are the two most prominent environmental factors that lead to cuSCC initiation, we undertook this study to test whether more acute molecular responses to UV and wounding overlapped with molecular signatures of cuSCC. We reasoned that transcriptional signatures in common between acutely UV-exposed skin, wounded skin, and cuSCC tumors, might enable us to identify important pathways contributing to cuSCC. We performed transcriptomic analysis on acutely UV-exposed human skin and integrated those findings with datasets from wounded skin and our transcriptomic data on cuSCC using functional pair analysis, GSEA, and pathway analysis. Integrated analyses revealed significant overlap between these three datasets, thus highlighting deep molecular similarities these biological processes, and we identified Oncostatin M (OSM) as a potential common upstream driver. Expression of OSM and its downstream targets correlated with poorer overall survival in head and neck SCC patients. In vitro, OSM promoted invasiveness of keratinocytes and cuSCC cells and suppressed apoptosis of irradiated keratinocytes. Together, these results support the concept of using an integrated, biologically-informed approach to identify potential promoters of tumorigenesis.

Graphene oxide (GO) and its derivatives are currently being explored for the modification of bone biomaterials. However, the effect of GO coatings on immunoregulation and subsequent impacts on osteogenesis are not known. In this study, GO was coated on pure titanium using dopamine. GO-coated titanium (Ti-GO) surfaces exhibited good biocompatibility, with the ability to stimulate the expression of osteogenic genes, and extracellular matrix mineralization in human mesenchymal stromal cells (hMSCs). Interestingly, it was found that GO-coated surfaces could manipulate the polarization of macrophages and expression of inflammatory cytokines via the Toll-like receptor pathway. Under physiological conditions, Ti-GO activated macrophages and induced mild inflammation and a pro-osteogenic environment, characterized by a slight increase in the levels of proinflammatory cytokines, as well as increased expression of the TGF-β1 and oncostatin M genes. In an environment mimicking acute inflammatory conditions, Ti-GO attenuated inflammatory responses, as shown by the downregulation of proinflammatory cytokines. Conditioned medium collected from macrophages stimulated by Ti-GO played a significant stimulatory role in the osteogenic differentiation of hMSCs. In summary, GO-coated surfaces displayed beneficial immunomodulatory effects in osteogenesis, indicating that GO could be a potential substance for the modification of bone scaffolds and implants., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020. Published by Elsevier B.V.)

The activation of osteoblasts is significantly correlated to prostate tumor bone metastasis and bone loss. Oncostatin M (OSM) could promote breast cancer metastasis to bone. However, its role and mechanism in prostate cancer bone metastasis remain unclear. MicroRNAs (miRNAs) could play important roles in cancers via post-transcriptionally regulating target genes via binding to specific sequences in the 3' UTR of downstream target genes. In the present study, we performed microarray profiling analyses to identify differentially-expressed miRNAs in preosteoclast before and after osteoclast differentiation that could target OSM. miR-181b-5p was downregulated during Raw264.7 cells differentiation into osteoclast. By direct targeting OSM 3' UTR, miR-181b-5p inhibited OSM messenger RNA expression and protein levels, subsequently decreasing IL-6 and AREG and increasing OPG, while OSM overexpression exerted an opposing effect. More importantly, co-culture with miR-181b-5p-overexpressing differentiated Raw264.7 cells suppressed proliferation, migration, and invasion of mouse prostate cancer RM-1 cells, while co-culture with OSM-overexpressing Raw264.7 cells led to opposing cellular effects. More importantly, the effects of miR-181b-5p on osteoclastogenic factors and RM-1 cells could be significantly reversed by OSM overexpression. In summary, miR-181b-5p/OSM axis could be a viable therapeutic target for patients with surgically removed primary tumors to reduce bone metastasis and prevent bone loss., (© 2019 Wiley Periodicals, Inc.)

Background: Hepatic myofibroblasts (MFs) can originate from hepatic stellate cells, portal fibroblasts, or bone marrow-derived mesenchymal stem cells and can migrate towards the site of injury by aligning with nascent and established fibrotic septa in response to several mediators. Oncostatin M (OSM) is known to orchestrate hypoxia-modulated hepatic processes involving the hypoxia-inducible factor 1 (HIF-1)., Methods: In vivo and in vitro experiments were performed to analyze the expression of OSM and OSM-receptor (OSMR) in three murine models of non-alcoholic-fatty liver disease (NAFLD) and -steatohepatitis (NASH) and in human NASH patients as well as the action of OSM on phenotypic responses of human MFs., Results: Hepatic OSM and OSMR levels were overexpressed in three murine NASH models and in NASH patients. OSM stimulates migration in human MFs by involving early intracellular ROS generation and activation of Ras/Erk, JNK1/2, PI3K/Akt as well as STAT1/STAT3 pathways and HIF-1α. OSM-dependent migration relies on a biphasic mechanism requiring early intracellular generation of reactive oxygen species (ROS) and late HIF1-dependent expression and release of VEGF., Conclusion: OSM is overexpressed in experimental and human progressive NAFLD and can act as a profibrogenic factor by directly stimulating migration of hepatic MFs., Competing Interests: The authors declare no conflict of interest.

Human Oncostatin M (OSM), initially discovered as a tumour inhibitory factor secreted from U-937 cells, is a gp130 (IL-6/LIF) cytokine family member that exhibits pleiotropic effects in inflammation, haematopoiesis, skeletal tissue alteration, liver regeneration, cardiovascular and metabolic diseases. Cytoplasmic expression of OSM in Escherichia coli results in inclusion bodies, and complex solubilisation, refolding and purification is required to prepare bioactive protein. Herein, eight N-terminal fusion variants of OSM with hexahistidine (His6) tag and seven solubility-enhancing tags, including thioredoxin (Trx), small ubiquitin-related modifier (Sumo), glutathione S-transferase (GST), maltose-binding protein (MBP), N-utilisation substance protein A (Nusa), human protein disulphide isomerase (PDI) and the b'a' domain of PDI (PDIb'a'), were tested for soluble OSM expression in E. coli. The His6-OSM plasmid was also introduced into genetically engineered Origami 2 and SHuffle strains to test expression of the protein. At 18 °C, MBP-tagged OSM was highly expressed and solubility was dramatically enhanced. In addition, His6-OSM was more highly expressed and soluble in Origami 2 and SHuffle strains than in BL21(DE3). MBP-OSM and His6-OSM were purified more than 95% with yields of 11.02 mg and 3.27 mg from a 500 mL culture. Protein identity was confirmed by mass spectroscopy, and bioactivity was demonstrated by in vitro inhibition of Th17 cell differentiation.

Objective: Previous studies indicate a role for Oncostatin M (OSM) in atherosclerosis and other chronic inflammatory diseases for which inhibitory antibodies are in development. However, to date no intervention studies with OSM have been performed, and its relation to coronary heart disease (CHD) has not been studied., Approach and Results: Gene expression analysis on human normal arteries (n = 10) and late stage/advanced carotid atherosclerotic arteries (n = 127) and in situ hybridization on early human plaques (n = 9) showed that OSM, and its receptors, OSM receptor (OSMR) and Leukemia Inhibitory Factor Receptor (LIFR) are expressed in normal arteries and atherosclerotic plaques. Chronic OSM administration in APOE*3Leiden.CETP mice (n = 15/group) increased plasma E-selectin levels and monocyte adhesion to the activated endothelium independently of cholesterol but reduced the amount of inflammatory Ly-6CHigh monocytes and atherosclerotic lesion size and severity. Using aptamer-based proteomics profiling assays high circulating OSM levels were shown to correlate with post incident CHD survival probability in the AGES-Reykjavik study (n = 5457)., Conclusions: Chronic OSM administration in APOE*3Leiden.CETP mice reduced atherosclerosis development. In line, higher serum OSM levels were correlated with improved post incident CHD survival probability in patients, suggesting a protective cardiovascular effect., Competing Interests: I have read the journal's policy and the authors of this manuscript have the following competing interests: Danielle van Keulen and Dennie Tempel are employed by Quorics B.V., Maarten D Sollewijn Gelpke by Molecular Profiling Consulting, Lori L Jennings by Novartis and Kim Holmstrøm and Boye Schnack Nielsen PhD by Bioneer A/S. There are no patents, products in development or marketed products to declare. This does not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials,as detailed online in the guide for authors.

The fibrogenic response in tissue-resident fibroblasts is determined by the balance between activation and repression signals from the tissue microenvironment. While the molecular pathways by which transforming growth factor-1 (TGF-β1) activates pro-fibrogenic mechanisms have been extensively studied and are recognized critical during fibrosis development, the factors regulating TGF-β1 signaling are poorly understood. Here we show that macrophage hypoxia signaling suppresses excessive fibrosis in a heart via oncostatin-m (OSM) secretion. During cardiac remodeling, Ly6C hi monocytes/macrophages accumulate in hypoxic areas through a hypoxia-inducible factor (HIF)-1α dependent manner and suppresses cardiac fibroblast activation. As an underlying molecular mechanism, we identify OSM, part of the interleukin 6 cytokine family, as a HIF-1α target gene, which directly inhibits the TGF-β1 mediated activation of cardiac fibroblasts through extracellular signal-regulated kinase 1/2-dependent phosphorylation of the SMAD linker region. These results demonstrate that macrophage hypoxia signaling regulates fibroblast activation through OSM secretion in vivo.

Diabetes impairs the mobilization of hematopoietic stem/progenitor cells (HSPCs) from the bone marrow (BM), which can worsen the outcomes of HSPC transplantation and of diabetic complications. In this study, we examined the oncostatin M (OSM)-p66Shc pathway as a mechanistic link between HSPC mobilopathy and excessive myelopoiesis. We found that streptozotocin-induced diabetes in mice skewed hematopoiesis toward the myeloid lineage via hematopoietic-intrinsic p66Shc. The overexpression of Osm resulting from myelopoiesis prevented HSPC mobilization after granulocyte colony-stimulating factor (G-CSF) stimulation. The intimate link between myelopoiesis and impaired HSPC mobilization after G-CSF stimulation was confirmed in human diabetes. Using cross-transplantation experiments, we found that deletion of p66Shc in the hematopoietic or nonhematopoietic system partially rescued defective HSPC mobilization in diabetes. Additionally, p66Shc mediated the diabetes-induced BM microvasculature remodeling. Ubiquitous or hematopoietic restricted Osm deletion phenocopied p66Shc deletion in preventing diabetes-associated myelopoiesis and mobilopathy. Mechanistically, we discovered that OSM couples myelopoiesis to mobilopathy by inducing Cxcl12 in BM stromal cells via nonmitochondrial p66Shc. Altogether, these data indicate that cell-autonomous activation of the OSM-p66Shc pathway leads to diabetes-associated myelopoiesis, whereas its transcellular hematostromal activation links myelopoiesis to mobilopathy. Targeting the OSM-p66Shc pathway is a novel strategy to disconnect mobilopathy from myelopoiesis and restore normal HSPC mobilization., (© 2019 by the American Diabetes Association.)

For a long time, the central nervous system (CNS) was believed to be an immune privileged organ. In the last decades, it became apparent that the immune system interacts with the CNS not only in pathological, but also in homeostatic situations. It is now clear that immune cells infiltrate the healthy CNS as part of immune surveillance and that immune cells communicate through cytokines with CNS resident cells. In pathological conditions, an enhanced infiltration of immune cells takes place to fight the pathogen. A well-known family of cytokines is the interleukin (IL)-6 cytokine family. All members are important in cell communication and cell signaling in the immune system. One of these members is oncostatin M (OSM), for which the receptor is expressed on several cells of the CNS. However, the biological function of OSM in the CNS is not studied in detail. Here, we briefly describe the general aspects related to OSM biology, including signaling and receptor binding. Thereafter, the current understanding of OSM during CNS homeostasis and pathology is summarized.

Oncostatin M (OSM) and its receptor (OSMR) are members of the interleukin-6 family cytokines. Although OSM and OSMR expression was detected in human ovaries, their function and regulation during follicle development, ovulation and luteolysis have not been studied in any species. The aim of the present study was to investigate the levels of OSM and OSMR mRNA in bovine ovaries and the effect of OSM treatment on cultured granulosa cells. OSM mRNA was not detected in granulosa cells obtained from follicles around the time of follicular deviation and from pre-ovulatory follicles, whereas OSMR transcript levels were greater in granulosa cells of atretic subordinate follicles (P < 0.001). Abundance of OSMR mRNA increased in granulosa cells of preovulatory follicles, collected at 12 and 24 h after the ovulatory stimulus with gonadotropins (P < 0.001). In the luteal tissue, OSM mRNA abundance levels were higher at 24-48 h after PGF-induced luteolysis (P < 0.01) compared to 0 h, whereas OSMR mRNA was transiently increased at 2 h after PGF treatment (P < 0.05). In cultured granulosa cells, 10 ng/mL OSM in the presence of FSH increased BAX/BCL2 mRNA ratio (P < 0.05) compared to the control. Moreover, 100 ng/mL OSM in the presence of FSH increased OSMR (P < 0.05) and decreased XIAP mRNA (P < 0.05) levels, compared to the control group. These findings provide the first evidence that OSMR is regulated during follicle atresia, ovulation and luteolysis, and that OSM from other cells may mediate granulosa and luteal cell function, regulating the expression of genes involved in cell's viability., (Copyright © 2018 Elsevier Inc. All rights reserved.)

The pleiotropic interleukin-6 (IL-6)-type cytokine oncostatin M (OSM) signals in multiple cell types, affecting processes such as cell differentiation, hematopoiesis, and inflammation. In humans, OSM exerts its effects through activation of either of two different heterodimeric receptor complexes, formed by glycoprotein 130 (gp130) and either OSM receptor (OSMR) or leukemia inhibitory factor receptor (LIFR). In contrast, the mouse OSM orthologue acts mainly through dimers containing OSMR and gp130 and shows limited activity through mouse LIFR. Despite their structural similarity, neither human nor mouse OSM signal through the other species' OSMR. The molecular basis for such species-specific signaling, however, remains poorly understood. To identify key molecular features of OSM that determine receptor activation in humans and mice, we generated chimeric mouse-human cytokines. Replacing regions within binding site III of murine OSM with the human equivalents showed that the cytokine's AB loop was critical for receptor selection. Substitutions of individual amino acids within this region demonstrated that residues Asn-37, Thr-40, and Asp-42 of the murine cytokine were responsible for limited LIFR activation and absence of human OSMR/LIFR signaling. In human OSM, Lys-44 appeared to be the main residue preventing mouse OSMR activation. Our data reveal that individual amino acids within the AB loop of OSM determine species-specific activities. These mutations might reflect a key step in the evolutionary process of this cytokine, in which receptor promiscuity gives way to ligand-receptor specialization., (© 2018 Adrian-Segarra et al.)

Idiopathic pulmonary fibrosis (IPF) is considered to be an ailment of the lungs that cannot be cured, wherein the lung tissues are characterized by increased thickness and stiffness, and/or scars. Despite the fact that extensive success has been achieved regarding the molecular diagnostics and pathobiology, the basic pathogenesis associated with IPF has not yet been fully elucidated and requires further clarification. In the current research, the changes in microRNA (miRNA) and mRNA expression in IPF were investigated through an integrative network technique. The authentic miRNA and mRNA expression profiling datasets were downloaded from Gene Expression Omnibus, followed by identification of differentially expressed miRNAs and mRNAs with use of the Significance Analysis of Microarrays algorithm. Expansion of the molecular targets associated with miRNAs was performed with the use of CyTargetLinker in Cytoscape, which was succeeded by validation with the use of mRNA array expression profiling. The incorporated miRNA‑mRNA network covered 27 genes, in addition to 22 miRNAs that were associated with IPF development. As revealed by the functional enrichment analysis, the cytokine‑cytokine receptor interaction and glycine, serine and threonine metabolism signalling pathways were extensively associated with IPF development. Overall, the present incorporated network illustrated the key link between miRNA and genes in IPF; in particular, it was elucidated that miR‑409‑5p and has‑miR‑376c, together with their target genes (C‑C motif chemokine ligand 20 and oncostatin M), are likely candidates involved in the promotion of IPF initiation and progression.

Tight junctions (TJs) alteration is commonly seen in airway inflammatory diseases. Oncostatin M (OSM) is an inflammatory mediator associated with chronic rhinosinusitis with nasal polyps (CRSwNP). We have previously shown that human nasal epithelial cells (hNECs) are highly permissive cells for influenza A virus (IAV). However, its role in TJs alteration and the effects of IAV on inducing OSM expression in nasal epithelium remains to be further investigated. In this study, OSM and TJs expression was measured and compared between inferior turbinate from healthy controls and nasal polyps from CRSwNP. Additionally, hNECs cultured at air-liquid interface (ALI) were infected with H3N2 influenza virus to study the role of influenza virus in inducing epithelial OSM expression as a possible means of exacerbation. The expression of ZO-1, claudin-1, and occludin was markedly decreased and correlated negatively with that of OSM in CRSwNP. By using the in vitro hNEC model, H3N2 infection resulted in significantly increased OSM expression (2.2-, 4.7- and 3.9-fold higher at 8, 24, and 48 h post-infection vs. mock infection). Furthermore, OSM is found to co-localize with ciliated and goblet cells in hNECs infected with H3N2 influenza virus. Our findings demonstrated that increased OSM expression is implicated in CRSwNP as a possible mechanism of TJs' impairment, which can be further augmented following influenza infection via epithelial OSM expression, possibly contributing to exacerbations., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Bile acids (BAs) control metabolism and inflammation by interacting with several receptors. Here, we report that intravenous infusion of taurodeoxycholate (TDCA) decreases serum pro-inflammatory cytokines, normalizes hypotension, protects against renal injury, and prolongs mouse survival during sepsis. TDCA increases the number of granulocytic myeloid-derived suppressor cells (MDSC LT ) distinctive from MDSCs obtained without TDCA treatment (MDSC L ) in the spleen of septic mice. FACS-sorted MDSC LT cells suppress T-cell proliferation and confer protection against sepsis when adoptively transferred better than MDSC L . Proteogenomic analysis indicated that TDCA controls chromatin silencing, alternative splicing, and translation of the immune proteome of MDSC LT , which increases the expression of anti-inflammatory molecules such as oncostatin, lactoferrin and CD244. TDCA also decreases the expression of pro-inflammatory molecules such as neutrophil elastase. These findings suggest that TDCA globally edits the proteome to increase the number of MDSC LT cells and affect their immune-regulatory functions to resolve systemic inflammation during sepsis.

Purpose: To investigate the effect of oncostatin M (OSM) on protein expression levels and enzymatic activities of matrix metalloprotainase (MMP)-2 and MMP-9 in primary trophoblasts and the invasiveness thereof under normoxia and hypoxia conditions., Materials and Methods: Protein expression levels and enzymatic activities of MMP-2 and MMP-9 in primary trophoblasts under normoxia and hypoxia conditions were examined by Western blot and zymography, respectively. Effects of exogenous OSM on the in vitro invasion activity of trophoblasts according to oxygen concentration were also determined. Signal transducer and activator of transcription 3 (STAT3) siRNA was used to determine whether STAT3 activation in primary trophoblasts was involved in the effect of OSM., Results: OSM enhanced protein expression levels and enzymatic activities of MMP-2 and MMP-9 in term trophoblasts under hypoxia condition, compared to normoxia control (p<0.05). OSM-induced MMP-2 and MMP-9 enzymatic activities were significantly suppressed by STAT3 siRNA silencing under normoxia and hypoxia conditions (p<0.05). Hypoxia alone or OSM alone did not significantly increase the invasiveness of term trophoblasts. However, the invasion activity of term trophoblasts was significantly increased by OSM under hypoxia, compared to that without OSM treatment under normoxia., Conclusion: OSM might be involved in the invasiveness of extravillous trophoblasts under hypoxia conditions via increasing MMP-2 and MMP-9 enzymatic activities through STAT3 signaling. Increased MMP-9 activity by OSM seems to be more important in primary trophoblasts., Competing Interests: The authors have no financial conflicts of interest., (© Copyright: Yonsei University College of Medicine 2018.)

Progression of systemic scleroderma (SSc), a chronic connective tissue disease that causes a fibrotic phenotype, is highly heterogeneous amongst patients and difficult to accurately diagnose. To meet this clinical need, we developed a novel three-layer classification model, which analyses gene expression profiles from SSc skin biopsies to diagnose SSc severity. Two SSc skin biopsy microarray datasets were obtained from Gene Expression Omnibus. The skin scores obtained from the original papers were used to further categorize the data into subgroups of low (<18) and high (≥18) severity. Data was pre-processed for normalization, background correction, centering and scaling. A two-layered cross-validation scheme was employed to objectively evaluate the performance of classification models of unobserved data. Three classification models were used: support vector machine, random forest, and naive Bayes in combination with feature selection methods to improve performance accuracy. For both input datasets, random forest classifier combined with correlation-based feature selection (CFS) method and naive Bayes combined with CFS or support vector machine based recursive feature elimination method yielded the best results. Additionally, we performed a principal component analysis to show that low and high severity groups are readily separable by gene expression signatures. Ultimately, we found that our novel classification prediction model produced global gene signatures that significantly correlated with skin scores. This study represents the first report comparing the performance of various classification prediction models for gene signatures from SSc patients, using current clinical diagnostic factors. In summary, our three-classification model system is a powerful tool for elucidating gene signatures from SSc skin biopsies and can also be used to develop a prognostic gene signature for SSc and other fibrotic disorders., Competing Interests: The authors have declared that no competing interests exist.

Background: Systemic and chronic inflammatory conditions in patients with breast cancer have been associated with reduced patient survival and increased breast cancer aggressiveness. This paper characterizes the role of an inflammatory cytokine, oncostatin M (OSM), in the preintravasation aspects of breast cancer metastasis., Methods: OSM expression levels in human breast cancer tissue samples were assessed using tissue microarrays, and expression patterns based on clinical stage were assessed. To determine the in vivo role of OSM in breast cancer metastasis to the lung, we used three orthotopic breast cancer mouse models, including a syngeneic 4T1.2 mouse mammary cancer model, the MDA-MB-231 human breast cancer xenograft model, and an OSM-knockout (OSM-KO) mouse model. Progression of metastatic disease was tracked by magnetic resonance imaging and bioluminescence imaging. Endpoint analysis included circulating tumor cell (CTC) counts, lung metastatic burden analysis by qPCR, and ex vivo bioluminescence imaging., Results: Using tissue microarrays, we found that tumor cell OSM was expressed at the highest levels in ductal carcinoma in situ. This finding suggests that OSM may function during the earlier steps of breast cancer metastasis. In mice bearing MDA-MB-231-Luc2 xenograft tumors, peritumoral injection of recombinant human OSM not only increased metastases to the lung and decreased survival but also increased CTC numbers. To our knowledge, this is the first time that a gp130 family inflammatory cytokine has been shown to directly affect CTC numbers. Using a 4T1.2 syngeneic mouse model of breast cancer, we found that mice bearing 4T1.2-shOSM tumors with knocked down tumor expression of OSM had reduced CTCs, decreased lung metastatic burden, and increased survival compared with mice bearing control tumors. CTC numbers were further reduced in OSM-KO mice bearing the same tumors, demonstrating the importance of both paracrine- and autocrine-produced OSM in this process. In vitro studies further supported the hypothesis that OSM promotes preintravasation aspects of cancer metastasis, because OSM induced both 4T1.2 tumor cell detachment and migration., Conclusions: Collectively, our findings suggest that OSM plays a crucial role in the early steps of metastatic breast cancer progression, resulting in increased CTCs and lung metastases as well as reduced survival. Therefore, early therapeutic inhibition of OSM in patients with breast cancer may prevent breast cancer metastasis.

Oncostatin M (OSM) and leukemia inhibitory factor (LIF) are closely related members of the interleukin-6 (IL-6) cytokine family. Both cytokines share a common origin and structure, and both interact through a specific region, termed binding site III, to activate a dimeric receptor complex formed by glycoprotein 130 (gp130) and LIF receptor (LIFR) in humans. However, only OSM activates the OSM receptor (OSMR)-gp130 complex. The molecular features that enable OSM to specifically activate the OSMR are currently unknown. To define specific sequence motifs within OSM that are critical for initiating signaling via OSMR, here we generated chimeric OSM-LIF cytokines and performed alanine-scanning experiments. Replacement of the OSM AB loop within OSM's binding site III with that of LIF abrogated OSMR activation, measured as STAT3 phosphorylation at Tyr-705, but did not compromise LIFR activation. Correspondingly, substitution of the AB loop and D-helix in LIF with their OSM counterparts was sufficient for OSMR activation. The alanine-scanning experiments revealed that residues Tyr-34, Gln-38, Gly-39, and Leu-45 (in the AB loop) and Pro-153 (in the D-helix) had specific roles in activating OSMR but not LIFR signaling, whereas Leu-40 and Cys-49 (in the AB loop), and Phe-160 and Lys-163 (in the D-helix) were required for activation of both receptors. Because most of the key amino acid residues identified here are conserved between LIF and OSM, we concluded that comparatively minor differences in a few amino acid residues within binding site III account for the differential biological effects of OSM and LIF., (© 2018 Adrian-Segarra et al.)

The oncostatin M (OSM) receptor (OSMR) shows frequent gene copy number gains and overexpression in cervical squamous cell carcinomas (SCCs), associated with adverse clinical outcomes. In SCC cells that overexpress OSMR, the major ligand OSM induces multiple pro-malignant effects, including invasion, secretion of angiogenic factors, and metastasis. Here, we demonstrate, for the first time, that OSMR overexpression in SCC cells activates cell-autonomous feed-forward signalling, via further expression of OSMR and OSM and sustained STAT3 activation, despite expression of the negative regulator suppressor of cytokine signalling 3 (SOCS3). The pro-malignant effects associated with OSMR overexpression are critically mediated by JAK-STAT3 activation, which is induced by exogenous OSM and also by autocrine OSM-OSMR interactions. Importantly, specific inhibition of OSM-OSMR interactions by neutralizing antibodies significantly inhibits STAT3 activation and feed-forward signalling, leading to reduced invasion, angiogenesis, and metastasis. Our findings are supported by data from 1254 clinical SCC samples, in which OSMR levels correlated with multiple cognate genes, including OSM, STAT3, and downstream targets. These data strongly support the development of OSM-OSMR-blocking antibodies as biologically targeted therapies against SCCs of the cervix and other anatomical sites. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd., (Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.)

Aim: To elucidate the role of microRNA-20a-5p (miR-20a-5p) in the pathogenesis of Vogt-Koyanagi-Harada (VKH) disease., Methods: Quantitative real-time PCR was used to quantify miR-20a-5p expression in CD4 + T cells from patients with active VKH and normal controls. The promoter methylation status of miR-20a-5p was detected by bisulfite sequencing PCR. Targets were evaluated by a luciferase reporter assay. The functional effects of miR-20a-5p on CD4 + T cells from patients with active VKH were assessed by upregulation or downregulation of its expression using liposomes., Results: The miR-20a-5p level was significantly decreased in CD4 + T cells from patients with active VKH as compared with normal controls. The two genes, oncostatin M (OSM) and C-C motif chemokine ligand 1 (CCL1), were identified as targets of miR-20a-5p. The upregulation of miR-20a-5p significantly suppressed interleukin 17 (IL-17) production in CD4 + T cells from patients with active VKH, whereas downregulation of miR-20a-5p exhibited an inverse effect. In addition, overexpression of OSM and CCL1 could rescue the effect of the upregulation of miR-20a-5p. Moreover, the level of miR-20a-5p was reduced in response to hypermethylation of the promoter. Further study showed that miR-20a-5p suppressed the activity of the phosphoinositide 3-kinase-AKT pathway., Conclusions: Our findings indicate that downregulation of miR-20a-5p is caused by promoter hypermethylation. MiR-20a-5p could also suppress the production of IL-17 by targeting OSM and CCL1 production in CD4 + T cells in patients with active VKH., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)