CREB regulates TNF-α-induced GM-CSF secretion via p38 MAPK in human lung fibroblasts

Serum galectin-3 as a biomarker of progression of idiopathic pulmonary fibrosis treated with nintedanib

Both serum and bronchoalveolar lavage fluid levels of galectin-3 (Gal-3) are elevated in patients with idiopathic pulmonary fibrosis (IPF). Phase II study on inhaler with Gal-3 inhibitor for IPF has been ongoing. In this study, 30 treatment-naive patients of IPF were prospectively enrolled and their sera were stored before and after nintedanib treatment. Though Gal-3 levels tended to increase after nintedanib treatment, in some patients, Gal-3 levels decreased immediately after the treatment. Patients whose serum Gal-3 levels decreased 1 month after nintedanib treatment tended to experience a smaller annual decline in forced vital capacity (FVC) than patients with increased Gal-3 levels. Furthermore, the rate of change in Gal-3 levels 1 month after nintedanib treatment positively correlated with the rate of annual FVC decline, whereas that of other fibrotic markers did not correlate with the rate of annual FVC decline. This study suggested that a decline in serum Gal-3 levels immediately after nintedanib treatment may predict less progression of IPF treated with nintedanib.

Traditional Chinese medicine in the treatment of Helicobacter pylori-related gastritis: The mechanisms of signalling pathway regulations

Helicobacter pylori-associated gastritis (HPAG) is a common condition of the gastrointestinal tract. However, extensive and long-term antibiotic use has resulted in numerous adverse effects, including increased resistance, gastrointestinal dysfunction, and increased recurrence rates. When these concerns develop, traditional Chinese medicine (TCM) may have advantages. TCM is based on the concept of completeness and aims to eliminate pathogens and strengthen the body. It has the potential to prevent this condition while also boosting the rate of Helicobacter pylori eradication. This review elaborates on the mechanism of TCM treatment for HPAG based on cellular signalling pathways, which reflects the flexibility of TCM in treating diseases and the advantages of multi-level, multi-pathway, and multi-target treatments for HPAG.

Gallic acid enhances GVL effects of T cells without exacerbating GVHD after haematopoietic stem cell transplantation

Allogeneic haematopoietic stem cell transplantation (allo-HSCT) is an effective therapy for acute myeloid leukaemia (AML), predominantly due to its potent graft-versus-leukaemia (GVL) effect. However, leukaemia relapse remains a major obstacle to the success of allo-HSCT. In this study, we demonstrated that gallic acid (GA), a natural dietary compound, can enhance T-cell-mediated GVL effects both in vitro and in vivo. GA-treated T cells exhibited increased activation and elevated secretion of cytotoxic cytokines, leading to the apoptosis of AML cells in co-culture systems in vitro. In a non-irradiated leukaemia mouse model, we showed that GA treatment prolonged the survival of leukaemic mice and reduced leukaemia cell infiltration. Further analysis revealed that GA treatment increased T-cell activation and tumour necrosis factor-α secretion. Moreover, integrated transcriptomic and proteomic analyses indicated that GA augments T-cell-mediated GVL effects through the activation of the MAPK and NF-κB pathways. Blocking these pathways individually diminished the protective effect of GA in AML model mice. Importantly, GA administration did not accelerate graft-versus-host disease (GVHD) progression in a mouse model. In conclusion, our study revealed that GA can enhance the GVL effects of T cells without exacerbating GVHD, offering insights into its potential to improve outcomes for patients after HSCT.

Ca2+ Signaling in Cardiovascular Fibroblasts

Fibrogenesis is a physiological process required for wound healing and tissue repair. It is induced by activation of quiescent fibroblasts, which first proliferate and then change their phenotype into migratory, contractile myofibroblasts. Myofibroblasts secrete extracellular matrix proteins, such as collagen, to form a scar. Once the healing process is terminated, most myofibroblasts undergo apoptosis. However, in some tissues, such as the heart, myofibroblasts remain active and sensitive to neurohumoral factors and inflammatory mediators, which lead eventually to excessive organ fibrosis. Many cellular processes involved in fibroblast activation, including cell proliferation, protein secretion and cell contraction, are highly regulated by intracellular Ca2+ signals. This review summarizes current research on Ca2+ signaling pathways underlying fibroblast activation. We present receptor- and ion channel-mediated Ca2+ signaling pathways, discuss how localized Ca2+ signals of the cell nucleus may be involved in fibroblast activation and present Ca2+-sensitive transcription pathways relevant for fibroblast biology. When investigated, we highlight how the function of Ca2+-handling proteins changes during cardiac and pulmonary fibrosis. Many aspects of Ca2+ signaling remain unexplored in different types of cardiovascular fibroblasts in relation to pathologies, and a better understanding of Ca2+ signaling in fibroblasts will help to design targeted therapies against fibrosis.

Effect of ginsenoside Rg1 on hematopoietic stem cells in treating aplastic anemia in mice via MAPK pathway

BACKGROUND

Aplastic anemia (AA) presents a significant clinical challenge as a life-threatening condition due to failure to produce essential blood cells, with the current therapeutic options being notably limited.

AIM

To assess the therapeutic potential of ginsenoside Rg1 on AA, specifically its protective effects, while elucidating the mechanism at play.

METHODS

We employed a model of myelosuppression induced by cyclophosphamide (CTX) in C57 mice, followed by administration of ginsenoside Rg1 over 13 d. The investigation included examining the bone marrow, thymus and spleen for pathological changes via hematoxylin-eosin staining. Moreover, orbital blood of mice was collected for blood routine examinations. Flow cytometry was employed to identify the impact of ginsenoside Rg1 on cell apoptosis and cycle in the bone marrow of AA mice. Additionally, the study further evaluated cytokine levels with enzyme-linked immunosorbent assay and analyzed the expression of key proteins in the MAPK signaling pathway via western blot.

RESULTS

Administration of CTX led to significant damage to the bone marrow's structural integrity and a reduction in hematopoietic cells, establishing a model of AA. Ginsenoside Rg1 successfully reversed hematopoietic dysfunction in AA mice. In comparison to the AA group, ginsenoside Rg1 provided relief by reducing the induction of cell apoptosis and inflammation factors caused by CTX. Furthermore, it helped alleviate the blockade in the cell cycle. Treatment with ginsenoside Rg1 significantly alleviated myelosuppression in mice by inhibiting the MAPK signaling pathway.

CONCLUSION

This study suggested that ginsenoside Rg1 addresses AA by alleviating myelosuppression, primarily through modulating the MAPK signaling pathway, which paves the way for a novel therapeutic strategy in treating AA, highlighting the potential of ginsenoside Rg1 as a beneficial intervention.

TNF-α can promote membrane invasion by activating the MAPK/MMP9 signaling pathway through autocrine in bone-invasive pituitary adenoma

AIMS

A bone-invasive pituitary adenoma exhibits aggressive behavior, leading to a worse prognosis. We have found that TNF-α promotes bone invasion by facilitating the differentiation of osteoclasts, however, before bone-invasive pituitary adenoma invades bone tissue, it needs to penetrate the dura mater, and this mechanism is not yet clear.

METHODS

We performed transcriptome microarrays on specimens of bone-invasive pituitary adenomas (BIPAs) and noninvasive pituitary adenomas (NIPAs) and conducted differential expressed gene analysis and enrichment analysis. We altered the expression of TNF-α through plasmids, then validated the effects of TNF-α on GH3 cells and verified the efficacy of the TNF-α inhibitor SPD304. Finally, the effects of TNF-α were validated in in vivo experiments.

RESULTS

Pathway act work showed that the MAPK pathway was significantly implicated in the pathway network. The expression of TNF-α, MMP9, and p-p38 is higher in BIPAs than in NIPAs. Overexpression of TNF-α elevated the expression of MAPK pathway proteins and MMP9 in GH3 cells, as well as promoted proliferation, migration, and invasion of GH3 cells. Flow cytometry indicated that TNF-α overexpression increased the G2 phase ratio in GH3 cells and inhibited apoptosis. The expression of MMP9 was reduced after blocking the P38 MAPK pathway; overexpression of MMP9 promoted invasion of GH3 cells. In vivo experiments confirm that the TNF-α overexpression group has larger tumor volumes. SPD304 was able to suppress the effects caused by TNF-α overexpression.

CONCLUSION

Bone-invasive pituitary adenoma secretes higher levels of TNF-α, which then acts on itself in an autocrine manner, activating the MAPK pathway and promoting the expression of MMP9, thereby accelerating the membrane invasion process. SPD304 significantly inhibits the effect of TNF-α and may be applied in the clinical treatment of bone-invasive pituitary adenoma.

Serum Induces the Subunit-Specific Activation of NF-κB in Proliferating Human Cardiac Stem Cells

Cardiovascular diseases (CVDs) are often linked to ageing and are the major cause of death worldwide. The declined proliferation of adult stem cells in the heart often impedes its regenerative potential. Thus, an investigation of the proliferative potential of adult human cardiac stem cells (hCSCs) might be of great interest for improving cell-based treatments of cardiovascular diseases. The application of human blood serum was already shown to enhance hCSC proliferation and reduce senescence. Here, the underlying signalling pathways of serum-mediated hCSC proliferation were studied. We are the first to demonstrate the involvement of the transcription factor NF-κB in the serum-mediated proliferative response of hCSCs by utilizing the NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC). RNA-Sequencing (RNA-Seq) revealed ATF6B, COX5B, and TNFRSF14 as potential targets of NF-κB that are involved in serum-induced hCSC proliferation.

Methyl lucidone inhibits airway inflammatory response by reducing TAK1 activity in human bronchial epithelial NCI-H292 cells

Background

Methyl lucidone (ML), a methyl derivative of lucidone, has anti-inflammatory properties. However, the molecular mechanisms that reduce the inflammatory effect of ML in human lung epithelial cells remain unkown. This study aimed to elucidate the molecular mechanisms underlying the anti-inflammatory effect of ML.

Methods

Four compounds (ML, methyl linderone, kanakugiol, and linderone) from Lindera erythrocarpa Makino were evaluated for their ability to reduce MUC5AC secretion levels in phorbol-12-myristate-13-acetate (PMA)-stimulated NCI-H292 cells using ELISA. The expression and secretion levels of inflammatory response-related proteins were analyzed using quantitative reverse transcription-PCR, ELISA, and western blotting. To determine whether ML directly regulates TGF-β-activated kinase 1 (TAK1), we performed an in vitro kinase assay.

Results

ML treatment effectively reduced the levels of inflammatory cytokines, including interleukin-1β and TNF-α, increased by stimulation. Furthermore, ML downregulated the pathway cascade of both IκB kinase (IKK)/NF-κB and p38 mitogen-activated protein (MAP) kinase/CREB by inhibiting the upstream kinase TAK1. An in vitro kinase analysis confirmed that ML treatment significantly reduced the kinase activity of TAK1.

Conclusion

ML pretreatment repressed the PMA-stimulated inflammation reaction by reducing the TAK1-mediated IKK/NF-κB and p38 MAP kinase/CREB signaling. These findings suggest that ML may improve respiratory health and can be used as a dietary supplement or functional food to prevent inflammatory lung diseases.

Inhibition of CREB promotes glucocorticoids action on airway inflammation in pediatric asthma by promoting ferroptosis of eosinophils

BACKGROUND

Pediatric asthma is a common chronic disease of childhood with airway inflammation. Cyclic adenosine monophosphate response element binding protein (CREB) plays a significant role in the transcription of proinflammatory genes, but its role in pediatric asthma has remained unclear. Herein, we investigated the functions of CREB in pediatric asthma.

METHODS

Eosinophils were purified from the peripheral blood of interleukin 5 (IL5) transgenic (IL5T) neonatal mice. The contents of CREB, long-chain fatty-acid-CoA ligase 4, transferrin receptor protein 1, ferritin heavy chain 1, and glutathione peroxidase 4 in eosinophils were examined by Western blot analysis. The viability of eosinophils, and the mean fluorescence intensity of Siglec F, C-C motif chemokine receptor 3 (CCR3), and reactive oxygen species were examined by flow cytometry. The concentration of iron in eosinophils was assessed by a commercial kit. The contents of malondialdehyde, glutathione, glutathione peroxidase, IL-5, and IL-4 were discovered by enzyme-linked-immunosorbent serologic assay. The C57BL/6 mice were randomly divided into four groups: sham, ovalbumin (OVA), OVA+Ad-shNC, and OVA+Ad-shCREB. The bronchial and alveolar structures were evaluated by hematoxylin and eosin staining. Leukocytes and eosinophils in the blood were measured using a HEMAVET 950.

RESULTS

The abundance of CREB in eosinophils was enhanced by CREB overexpression vector transfection, but reduced by short hairpin (sh)CREB transfection. Downregulation of CREB triggered the cell death of eosinophils. Knockdown of CREB could obviously contribute to ferroptosis of eosinophils. In addition, downregulation of CREB facilitated dexamethasone (DXMS, a type of glucocorticoid)-induced eosinophils death. Moreover, we established an asthma mouse model by OVA treatment. The CREB was upregulated in OVA group mice, but Ad-shCREB treatment obviously downregulated CREB level. Downregulation of CREB diminished OVA-induced asthmatic airway inflammation by reducing the number of inflammatory cells and the levels of proinflammatory factors. Downregulated CREB enhanced the anti-inflammatory effect of DXMS in OVA-induced mice.

CONCLUSION

Inhibition of CREB promoted the effect of glucocorticoids on airway inflammation in pediatric asthma through promoting ferroptosis of eosinophils.

Role of GM-CSF in lung balance and disease

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a hematopoietic growth factor originally identified as a stimulus that induces the differentiation of bone marrow progenitor cells into granulocytes and macrophages. GM-CSF is now considered to be a multi-origin and pleiotropic cytokine. GM-CSF receptor signals activate JAK2 and induce nuclear signals through the JAK-STAT, MAPK, PI3K, and other pathways. In addition to promoting the metabolism of pulmonary surfactant and the maturation and differentiation of alveolar macrophages, GM-CSF plays a key role in interstitial lung disease, allergic lung disease, alcoholic lung disease, and pulmonary bacterial, fungal, and viral infections. This article reviews the latest knowledge on the relationship between GM-CSF and lung balance and lung disease, and indicates that there is much more to GM-CSF than its name suggests.

Endoglin Modulates TGFβR2 Induced VEGF and Proinflammatory Cytokine Axis Mediated Angiogenesis in Prolonged DEHP-Exposed Breast Cancer Cells

Angiogenesis is the process of vascular network development and plays a crucial role in cancer growth, progression, and metastasis. Phthalates are a class of environmental pollutants that have detrimental effects on human health and are reported to increase cancer risk. However, the interplay between phthalate exposure and angiogenesis has not been investigated thoroughly. In this study, we investigated the effect of prolonged di (2-ethylhexyl) phthalate (DEHP) treatment on the angiogenic potential of triple-negative breast cancer. MDA-MB-231 cells were exposed to physiological concentrations of DEHP for more than three months. Prolonged DEHP exposure induced angiogenesis in breast cancer cells. Endoglin (ENG)/CD105 is a membrane glycoprotein and an auxiliary receptor of the TGFβ receptor complex. In endothelial cells, ENG is highly expressed and it is a prerequisite for developmental angiogenesis. A literature review highlights endoglin as a well-known mesenchymal stem cell marker responsible for vascular development and angiogenesis. NGS analysis showed that endoglin overexpression in DEHP-exposed MDA-MB-231 cells correlated with tumor development and growth. An in vivo zebrafish xenograft assay showed that VEGFA induced sprouting of the subintestinal vein (SIV) in embryos injected with DEHP-exposed cells. Endoglin knockdown reduced SIV sprouting and VEGFA expression in zebrafish embryos. An in vitro HUVEC tube formation assay showed that endoglin depletion reversed DEHP-induced VEGF-mediated HUVEC tube formation in coculture. DEHP-induced endoglin activated TGFβ/SMAD3/VEGF and MAPK/p38 signaling in MDA-MB-231 cells. A cytokine angiogenesis antibody array showed induced expression of the inflammatory cytokines IL1α, IL1β, IL6, and IL8, along with GMCSF and VEGF. Endoglin knockdown reversed DEHP-induced activation of the TGFβ/SMAD3/VEGF signaling axis, MAPK/p38 signaling, and cytokine regulation, limiting angiogenesis potential both in vivo and in vitro. Targeting endoglin might serve as a potential alternative treatment to control angiogenesis, leading to metastasis and limiting cancer progression.

GM-CSF: Orchestrating the Pulmonary Response to Infection

This review summarizes the structure and function of the alveolar unit, comprised of alveolar macrophage and epithelial cell types that work in tandem to respond to infection. Granulocyte-macrophage colony-stimulating factor (GM-CSF) helps to maintain the alveolar epithelium and pulmonary immune system under physiological conditions and plays a critical role in restoring homeostasis under pathologic conditions, including infection. Given the emergence of novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and global spread of coronavirus disease 2019 (COVID-19), with subsequent acute respiratory distress syndrome, understanding basic lung physiology in infectious diseases is especially warranted. This review summarizes clinical and preclinical data for GM-CSF in respiratory infections, and the rationale for sargramostim (yeast-derived recombinant human [rhu] GM-CSF) as adjunctive treatment for COVID-19 and other pulmonary infectious diseases.

Short Chain Fatty Acid Acetate Increases TNFα-Induced MCP-1 Production in Monocytic Cells via ACSL1/MAPK/NF-κB Axis

Short-chain fatty acid (SCFA) acetate, a byproduct of dietary fiber metabolism by gut bacteria, has multiple immunomodulatory functions. The anti-inflammatory role of acetate is well documented; however, its effect on monocyte chemoattractant protein-1 (MCP-1) production is unknown. Similarly, the comparative effect of SCFA on MCP-1 expression in monocytes and macrophages remains unclear. We investigated whether acetate modulates TNFα-mediated MCP-1/CCL2 production in monocytes/macrophages and, if so, by which mechanism(s). Monocytic cells were exposed to acetate with/without TNFα for 24 h, and MCP-1 expression was measured. Monocytes treated with acetate in combination with TNFα resulted in significantly greater MCP-1 production compared to TNFα treatment alone, indicating a synergistic effect. On the contrary, treatment with acetate in combination with TNFα suppressed MCP-1 production in macrophages. The synergistic upregulation of MCP-1 was mediated through the activation of long-chain fatty acyl-CoA synthetase 1 (ACSL1). However, the inhibition of other bioactive lipid enzymes [carnitine palmitoyltransferase I (CPT I) or serine palmitoyltransferase (SPT)] did not affect this synergy. Moreover, MCP-1 expression was significantly reduced by the inhibition of p38 MAPK, ERK1/2, and NF-κB signaling. The inhibition of ACSL1 attenuated the acetate/TNFα-mediated phosphorylation of p38 MAPK, ERK1/2, and NF-κB. Increased NF-κB/AP-1 activity, resulting from acetate/TNFα co-stimulation, was decreased by ACSL1 inhibition. In conclusion, this study demonstrates the proinflammatory effects of acetate on TNF-α-mediated MCP-1 production via the ACSL1/MAPK/NF-κB axis in monocytic cells, while a paradoxical effect was observed in THP-1-derived macrophages.

The Phosphodiesterase Inhibitor Ensifentrine Reduces Production of Proinflammatory Mediators in Well Differentiated Bronchial Epithelial Cells by Inhibiting PDE4

Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) anion channel that impair airway salt and fluid secretion. Excessive release of proinflammatory cytokines and chemokines by CF bronchial epithelium during airway infection leads to chronic inflammation and a slow decline in lung function; thus, there is much interest in finding safe and effective treatments that reduce inflammation in CF. We showed previously that the cyclic nucleotide phosphodiesterase (PDE) inhibitor ensifentrine (RPL554; Verona Pharma) stimulates the channel function of CFTR mutants with abnormal gating and also those with defective trafficking that are partially rescued using a clinically approved corrector drug. PDE inhibitors also have known anti-inflammatory effects; therefore, we examined whether ensifentrine alters the production of proinflammatory cytokines in CF bronchial epithelial cells. Ensifentrine reduced the production of monocyte chemoattractant protein-1 and granulocyte monocyte colony-stimulating factor (GM-CSF) during challenge with interleukin-1β Comparing the effect of ensifentrine with milrinone and roflumilast, selective PDE3 and PDE4 inhibitors, respectively, demonstrated that the anti-inflammatory effect of ensifentrine was mainly due to inhibition of PDE4. Beneficial modulation of GM-CSF was further enhanced when ensifentrine was combined with low concentrations of the β 2-adrenergic agonist isoproterenol or the corticosteroid dexamethasone. The results indicate that ensifentrine may have beneficial anti-inflammatory effects in CF airways particularly when used in combination with β 2-adrenergic agonists or corticosteroids. SIGNIFICANCE STATEMENT: Airway inflammation that is disproportionate to the burden of chronic airway infection causes much of the pathology in the cystic fibrosis (CF) lung. We show here that ensifentrine beneficially modulates the release of proinflammatory factors in well differentiated CF bronchial epithelial cells that is further enhanced when combined with β2-adrenergic agonists or low-concentration corticosteroids. The results encourage further clinical testing of ensifentrine, alone and in combination with β2-adrenergic agonists or low-concentration corticosteroids, as a novel anti-inflammatory therapy for CF.

[Expression of CREB in children with recurrent wheezing and its effect on ORMDL3 gene expression]

OBJECTIVE

To study the expression level of cAMP response element-binding protein (CREB) in children with recurrent wheezing under three years of age and its effect on the expression of the serum orosomucoid 1-like protein 3 (ORMDL3) gene.

METHODS

Thirty-six children with recurrent wheezing under three years of age who visited the hospital from June 2017 to June 2019 were selected as the recurrent wheezing group. Twenty-four healthy children from physical examination were selected as the control group. The CREB expression level in peripheral blood was measured by quantitative real-time PCR. Human bronchial epithelial cells (BEAS-2B) were cultured, and dual-luciferase reporter assay and quantitative real-time PCR were used to investigate the effects of overexpression and siRNA interference of CREB on the promoter activity and mRNA expression of the ORMDL3 gene in the BEAS-2B cells.

RESULTS

The expression level of CREB in the recurrent wheezing group was significantly higher than that in the control group (P<0.001). In BEAS-2B cells, overexpression of CREB significantly up-regulated the promoter activity and mRNA expression of the ORMDL3 gene (P<0.05), while siRNA interference of CREB significantly reduced the promoter activity and mRNA expression of the ORMDL3 gene (P<0.05).

CONCLUSIONS

The expression of CREB is increased in children with recurrent wheezing, and CREB may be involved in the pathogenesis of recurrent wheezing by regulating expression of the ORMDL3 gene.

Pharmacological inhibition of GSK3 promotes TNFα-induced GM-CSF via up-regulation of ERK signaling in nasopharyngeal carcinoma (NPC)

Granulocyte-macrophage colony stimulating factor (GM-CSF) functions to drive nasopharyngeal cancer (NPC) metastasis via recruitment and activation of macrophages. However, the source and the regulation of GM-CSF in tumor microenvironment of NPC are not fully understood. In this study, we found that TNFα induced GM-CSF production in NPC CNE1, CNE2, and 5-8F cells in time- and dose-dependent manners. GM-CSF production was tolerant, because the pre-treatment of NPC cells with TNFα down-regulated the GM-CSF production induced by TNFα re-treatment. TNFα activated glycogen synthase kinase-3 (GSK-3), which is an enzyme to regulate glycogen synthesis, and also is a critical downstream element of the PI3K/Akt to regulate cell survival. GSK3 inhibitors up-regulated TNFα-induced GM-CSF, and reversed GM-CSF tolerance induced by TNFα pre-treatment, suggesting that GSK3 activation down-regulated GM-CSF production. GM-CSF down-regulation was not related to ubiquitin-editing enzyme A20. The over-expression of A20 did not regulate GM-CSF production induced by TNFα. However, GSK3 inhibitors up-regulated ERK activation, which contributed to the production of GM-CSF induced by TNFα, suggesting that GSK3 negatively regulated TNFα-induced GM-CSF via down-regulation of ERK signaling. Taking together, these results suggested that GSK3 pathway may be a target for the regulation of TNFα-induced GM-CSF in the tumor microenvironment.

Glucagon-like peptide-1 suppresses neuroinflammation and improves neural structure

Glucagon-like peptide-1 (GLP-1) is a hormone mainly secreted from enteroendocrine L cells. GLP-1 and its receptor are also expressed in the brain. GLP-1 signaling has pivotal roles in regulating neuroinflammation and memory function, but it is unclear how GLP-1 improves memory function by regulating neuroinflammation. Here, we demonstrated that GLP-1 enhances neural structure by inhibiting lipopolysaccharide (LPS)-induced inflammation in microglia with the effects of GLP-1 itself on neurons. Inflammatory secretions of BV-2 microglia by LPS aggravated mitochondrial function and cell survival, as well as neural structure in Neuro-2a neurons. In inflammatory condition, GLP-1 suppressed the secretion of tumor necrosis factor-alpha (TNF-α)-associated cytokines and chemokines in BV-2 microglia and ultimately enhanced neurite complexity (neurite length, number of neurites from soma, and secondary branches) in Neuro-2a neurons. We confirmed that GLP-1 improves neurite complexity, dendritic spine morphogenesis, and spine development in TNF-α-treated primary cortical neurons based on altered expression levels of the factors related to neurite growth and spine morphology. Given that our data that GLP-1 itself enhances neurite complexity and spine morphology in neurons, we suggest that GLP-1 has a therapeutic potential in central nervous system diseases.

Asian Sand Dust Upregulates IL-6 and IL-8 via ROS, JNK, ERK, and CREB Signaling in Human Nasal Fibroblasts

Background

Asian sand dust (ASD) profoundly affects respiratory health by inducing inflammation and causing upper airway inflammatory diseases. Interleukin (IL)-6 and IL-8 are pro-inflammatory mediators that are involved in upper airway inflammatory diseases. However, the effect of ASD on the production of IL-6 and IL-8 in nasal fibroblasts has not been adequately studied. We investigated the effect of ASD on the induction of pro-inflammatory mediators and its underlying mechanisms in nasal fibroblasts.

Methods

Real-time cytotoxicity assays were used to determine the effect of ASD on the viability of fibroblasts. Enzyme-linked immunosorbent assays and real-time polymerase chain reactions were performed to determine whether ASD induced the expression of IL-6 and IL-8. Reactive oxygen species (ROS) were quantified using 2, 7-dichlorofluorescein-diacetate and MitoSOX Red. Induction of IL-6 and IL-8 signal transduction pathways by ASD was confirmed by Western blotting. Ex vivo culture of the inferior turbinate tissue was performed to confirm the effects of ASD.

Results

ASD upregulated ROS levels, and this in turn promoted IL-6 and IL-8 expression through the MAPK (JNK and ERK) and CREB signaling pathways in nasal fibroblasts. However, ASD did not induce phosphorylation of p38. Specific inhibitors of each pathway (ROS, JNK, ERK, and CREB inhibitors) suppressed ASD-induced IL-6 and IL-8 upregulation.

Conclusions

ASD induces pro-inflammatory mediators, and the increased levels of IL-6 and IL-8 might be associated with the pathogenesis of chronic rhinosinusitis.

ACSL1 Regulates TNFα-Induced GM-CSF Production by Breast Cancer MDA-MB-231 Cells

Overexpression of granulocyte-macrophage colony-stimulating factor (GM-CSF) in different types of cancer is associated with tumor growth and progression. Tumor necrosis factor-α (TNFα) is involved in the induction of GM-CSF in different cells; however, the underlying molecular mechanism in this production of GM-CSF has not been fully revealed. Recently, it was noted that TNFα mediates inflammatory responses through long-chain acyl-CoA synthetase 1 (ACSL1). Therefore, we investigated the role of ACSL1 in the TNFα mediated production of GM-CSF. Our results showed that MDA-MB-231 cells displayed increased GM-CSF mRNA expression and secretion after incubation with TNFα. Blocking of ACSL1 activity in the cells with triacsin C markedly suppressed the secretion of GM-CSF. However, inhibition of β-oxidation and ceramide biosynthesis were not required for GM-CSF production. By small interfering RNA mediated knockdown, we further demonstrated that TNFα induced GM-CSF production was significantly diminished in ACSL1 deficient cells. TNFα mediated GM-CSF expression was significantly reduced by inhibition of p38 MAPK, ERK1/2 and NF-κB signaling pathways. TNFα induced phosphorylation of p38, ERK1/2, and NF-κB was observed during the secretion of GM-CSF. On the other hand, inhibition of ACSL1 activity attenuates TNFα mediated phosphorylation of p38 MAPK, ERK1/2, and NF-κB in the cells. Importantly, our findings suggest that ACSL1 plays an important role in the regulation of GM-CSF induced by TNFα in MDA-MB-231 cells. Therefore, ACSL1 may be considered as a potential novel therapeutic target for tumor growth.

JAX2, an ethanol extract of Hyssopus cuspidatus Boriss, can prevent bronchial asthma by inhibiting MAPK/NF-κB inflammatory signaling

BACKGROUND

Hyssopus cuspidatus Boriss has been used to treat bronchial asthma for many years in Uighur medicine. JAX2, an ethanol extract from this plant, has effectiveness against bronchial asthma. However, the molecular basis for the anti-inflammatory effects of JAX2 remains unclear.

PURPOSE

This study aimed to evaluate the mechanism of JAX2 against bronchial asthma.

METHODS

We established an asthma model in rats using ovalbumin (OVA), and an inflammatory model in RAW264.7 cells using lipopolysaccharide (LPS) stimulation. To evaluate the anti-inflammatory effects of JAX2, the concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-4, IL-6, IL-17, eotaxin and immunoglobulin (Ig)E were measured by enzyme-linked immunosorbent assay (ELISA). Cell viability was investigated by the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)2H-tetrazolium, inner salt (MTS) assay. Further, nitric oxide (NO) and reactive oxygen species (ROS) were determined using Griess reagent and 2,7-dichlorofluorescein diacetate. The phosphorylation of p-extracellular signal-regulated kinase (ERK), p-Jun-NH2-terminal kinase (JNK), p38 kinases (p38) and p-inhibitor of nuclear factor kappa-B kinase (IKK), and nuclear translocation of p-p65 kinases (p-p65) were determined by immunofluorescence to uncover the effects of JAX2 on the Mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) signaling pathways.

RESULTS

After JAX2 administration to rats, Interferon (IFN)-γ concentrations in BALF increased significantly. Further, the concentrations of TNF-α, IL-4, IL-6, IL-17 and eotaxin in BALF, and IgE in serum decreased. JAX2 decreased TNF-α, IL-6 and NO in cell supernatant, and reduced ROS intracellularly. Concurrently, IFN-γ concentrations increased in cell supernatant significantly. In LPS-induced RAW264.7 cells, JAX2 inhibited phosphorylation of p-ERK, p-JNK and p-38 MAPK. The subsequent phosphorylation of p-IKK and nuclear translocation of the p-p65 subunit of NF-κB were also suppressed.

CONCLUSION

Based on these findings, we believe that JAX2 has both preventive and treatment effects in bronchial asthma. Furthermore, in the RAW264.7 cell inflammatory model, JAX2 also inhibited NF-κB and MAPK signaling pathways.

Roles of Cyclic AMP Response Element Binding Activation in the ERK1/2 and p38 MAPK Signalling Pathway in Central Nervous System, Cardiovascular System, Osteoclast Differentiation and Mucin and Cytokine Production

There are many downstream targets of mitogen-activated protein kinase (MAPK) signalling that are involved in neuronal development, cellular differentiation, cell migration, cancer, cardiovascular dysfunction and inflammation via their functions in promoting apoptosis and cell motility and regulating various cytokines. It has been reported that cyclic AMP response element-binding protein (CREB) is phosphorylated and activated by cyclic AMP signalling and calcium/calmodulin kinase. Recent evidence also points to CREB phosphorylation by the MAPK signalling pathway. However, the specific roles of CREB phosphorylation in MAPK signalling have not yet been reviewed in detail. Here, we describe the recent advances in the study of this MAPK-CREB signalling axis in human diseases. Overall, the crosstalk between extracellular signal-related kinase (ERK) 1/2 and p38 MAPK signalling has been shown to regulate various physiological functions, including central nervous system, cardiac fibrosis, alcoholic cardiac fibrosis, osteoclast differentiation, mucin production in the airway, vascular smooth muscle cell migration, steroidogenesis and asthmatic inflammation. In this review, we focus on ERK1/2 and/or p38 MAPK-dependent CREB activation associated with various diseases to provide insights for basic and clinical researchers.

Tobacco Carcinogen-Induced Production of GM-CSF Activates CREB to Promote Pancreatic Cancer

Although smoking is a significant risk factor for pancreatic ductal adenocarcinoma (PDAC), the molecular mechanisms underlying PDAC development and progression in smokers are still unclear. Here, we show the role of cyclic AMP response element-binding protein (CREB) in the pathogenesis of smoking-induced PDAC. Smokers had significantly higher levels of activated CREB when compared with nonsmokers. Cell lines derived from normal pancreas and pancreatic intraepithelial neoplasm (PanIN) exhibited low baseline pCREB levels compared with PDAC cell lines. Furthermore, elevated CREB expression correlated with reduced survival in patients with PDAC. Depletion of CREB significantly reduced tumor burden after tobacco-specific nitrosamine 4-(methyl nitrosamino)-1-(3-pyridyl)-1-butanone (NNK) treatment, suggesting a CREB-dependent contribution to PDAC growth and progression in smokers. Conversely, NNK accelerated PanIN lesion and PDAC formation via GM-CSF-mediated activation of CREB in a PDAC mouse model. CREB inhibition (CREBi) in mice more effectively reduced primary tumor burden compared with control or GM-CSF blockade alone following NNK exposure. GM-CSF played a role in the recruitment of tumor-associated macrophages (TAM) and regulatory T cell (Treg) expansion and promotion, whereas CREBi significantly reduced TAM and Treg populations in NNK-exposed mice. Overall, these results suggest that NNK exposure leads to activation of CREB through GM-CSF, promoting inflammatory and Akt pathways. Direct inhibition of CREB, but not GM-CSF, effectively abrogates these effects and inhibits tumor progression, offering a viable therapeutic strategy for patients with PDAC.Significance: These findings identify GM-CSF-induced CREB as a driver of pancreatic cancer in smokers and demonstrate the therapeutic potential of targeting CREB to reduce PDAC tumor growth.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/21/6146/F1.large.jpg Cancer Res; 78(21); 6146-58. ©2018 AACR.

The Risk G Allele of the Single-Nucleotide Polymorphism rs928413 Creates a CREB1-Binding Site That Activates IL33 Promoter in Lung Epithelial Cells

Cytokine interleukin 33 (IL-33) is constitutively expressed by epithelial barrier cells, and promotes the development of humoral immune responses. Along with other proinflammatory mediators released by the epithelium of airways and lungs, it plays an important role in a number of respiratory pathologies. In particular, IL-33 significantly contributes to pathogenesis of allergy and asthma; genetic variations in the IL33 locus are associated with increased susceptibility to asthma. Large-scale genome-wide association studies have identified minor “G” allele of the single-nucleotide polymorphism rs928413, located in the IL33 promoter area, as a susceptible variant for early childhood and atopic asthma development. Here, we demonstrate that the rs928413(G) allele creates a binding site for the cAMP response element-binding protein 1 (CREB1) transcription factor. In a pulmonary epithelial cell line, activation of CREB1, presumably via the p38 mitogen-activated protein kinases (MAPK) cascade, activates the IL33 promoter containing the rs928413(G) allele specifically and in a CREB1-dependent manner. This mechanism may explain the negative effect of the rs928413 minor “G” allele on asthma development.

Sca-1+ cardiac fibroblasts promote development of heart failure

The causative effect of GM-CSF produced by cardiac fibroblasts to development of heart failure has not been shown. We identified the pathological GM-CSF-producing cardiac fibroblast subset and the specific deletion of IL-17A signaling to these cells attenuated cardiac inflammation and heart failure. We describe here the CD45^- CD31^- CD29⁺ mEF-SK4⁺ PDGFRα⁺ Sca-1⁺ periostin⁺ (Sca-1⁺ ) cardiac fibroblast subset as the main GM-CSF producer in both experimental autoimmune myocarditis and myocardial infarction mouse models. Specific ablation of IL-17A signaling to Sca-1⁺ periostin⁺ cardiac fibroblasts (Postn^Cre Il17ra^fl/fl ) protected mice from post-infarct heart failure and death. Moreover, Postn^Cre Il17ra^fl/fl mice had significantly fewer GM-CSF-producing Sca-1⁺ cardiac fibroblasts and inflammatory Ly6C^hi monocytes in the heart. Sca-1⁺ cardiac fibroblasts were not only potent GM-CSF producers, but also exhibited plasticity and switched their cytokine production profiles depending on local microenvironments. Moreover, we also found GM-CSF-positive cardiac fibroblasts in cardiac biopsy samples from heart failure patients of myocarditis or ischemic origin. Thus, this is the first identification of a pathological GM-CSF-producing cardiac fibroblast subset in human and mice hearts with myocarditis and ischemic cardiomyopathy. Sca-1⁺ cardiac fibroblasts direct the type of immune cells infiltrating the heart during cardiac inflammation and drive the development of heart failure.

Advanced Glycation End Products Enhance Murine Monocyte Proliferation in Bone Marrow and Prime Them into an Inflammatory Phenotype through MAPK Signaling

OBJECTIVE

Increased monocytes, particularly the inflammatory subset, are associated with accelerated atherosclerosis in diabetes through thus far incompletely defined mechanisms. The present study tested the hypothesis that advanced glycation end products (AGEs) promote bone marrow monocytes to proliferate and drive them into an inflammatory phenotype.

METHODS AND RESULTS

In vivo, AGEs (25 mg/kg i.p. for 7 days) increased proportions of CD115⁺ monocytes and the inflammatory subset, the CD115⁺Ly6C^high cells, in murine bone marrow (flow cytometry analysis (FCM)), and enhanced gene expression of proinflammatory cytokines (IL-1β and TNF-α) but only slightly upregulated mRNA expression of anti-inflammatory cytokine (IL-10) (real-time PCR) in monocytes. In vitro, when the monocytes were treated with different dosages of AGEs (50, 150, and 300 μg/mL), we found that proliferation (CCK8) but not apoptosis (FCM) of the monocytes was induced; the mRNA expressions of proinflammatory cytokines (IL-1β and TNF-α) and GM-CSF were upregulated in a dose-dependent manner while mRNA levels of IL-10 and M-CSF were changed much less in monocytes (real-time PCR). Furthermore, AGEs (300 μg/mL) significantly enhanced the expression of Ki67 in monocytes (immunofluorescence staining (IF)), and this dose of AGEs markedly increased secretion of GM-CSF but not that of M-CSF (ELISA). For a pathway study, the monocytes were stimulated by 300 μg/mL AGEs for different periods of time (0, 15, 30, and 120 min) and the activation of the MAPK pathway was tested (FCM); the results showed the p38 and ERK pathways were activated but not JNK signaling. Pretreatment with an inhibitor of p38 (SB203580) or ERK (U0126) attenuated AGE-induced gene expression of proinflammatory cytokines and GM-CSF (real-time PCR), as well as reversing AGE-induced Ki67 expression (IF).

CONCLUSIONS

AGEs promote bone marrow monocytes to proliferate and drive them into an inflammatory phenotype through p38 and ERK activation.

Genome-wide methylation analysis reveals differentially methylated loci that are associated with an age-dependent increase in bovine fibroblast response to LPS

BACKGROUND

Differences in DNA methylation are known to contribute to the development of immune-related disorders in humans but relatively little is known about how methylation regulates immune function in cattle. Utilizing whole-transcriptome analyses of bovine dermal fibroblasts, we have previously identified an age and breed-dependent up-regulation of genes within the toll-like receptor 4 (TLR4) pathway that correlates with enhanced fibroblast production of IL-8 in response to lipopolysaccharide (LPS). Age-dependent differences in IL-8 production are abolished by treatment with 5-aza-2-deoxycytidine and Trichostatin A (AZA-TSA), suggesting epigenetic regulation of the innate response to LPS. In the current study, we performed reduced representation bisulfite sequencing (RRBS) on fibroblast cultures isolated from the same animals at 5- and 16-months of age to identify genes that exhibit variable methylation with age. To validate the role of methylation in gene expression, six innate response genes that were hyper-methylated in young animals were assessed by RT-qPCR in fibroblasts from animals at different ages and from different breeds.

RESULTS

We identified 14,094 differentially methylated CpGs (DMCs) that differed between fibroblast cultures at 5- versus 16-months of age. Of the 5065 DMCs that fell within gene regions, 1117 were located within promoters, 1057 were within gene exons and 2891 were within gene introns and 67% were more methylated in young cultures. Transcription factor enrichment of the promoter regions hyper-methylated in young cultures revealed significant regulation by the key pro-inflammatory regulator, NF-κB. Additionally, five out of six chosen genes (PIK3R1, FES, NFATC1, TNFSF13 and RORA) that were more methylated in young cultures showed a significant reduction in expression post-LPS treatment in comparison with older cultures. Two of these genes, FES and NFATC1, were similarly down-regulated in Angus cultures that also exhibit a low LPS response phenotype.

CONCLUSIONS

Our study has identified immune-related loci regulated by DNA methylation in cattle that may contribute to differential cellular response to LPS, two of which exhibit an identical expression profile in both low-responding age and breed phenotypes. Methylation biomarkers of differential immunity may prove useful in developing selection strategies for replacement cows that are less susceptible to severe infections, such as coliform mastitis.