Prostaglandin E2 Induces IL-6 and IL-8 Production by the EP Receptors/Akt/NF-κB Pathways in Nasal Polyp-Derived Fibroblasts

The role of fibroblast in chronic rhinosinusitis with nasal polyps: a key player in the inflammatory process

INTRODUCTION

Fibroblasts are the primary supporting cells in connective tissue and have long been thought to contribute to chronic rhinosinusitis with nasal polyps (CRSwNP) by producing extracellular matrix (ECM), leading to fibrosis and tissue remodeling. However, recent studies have highlighted the critical role of nasal polyp-derived fibroblasts (NPDFs) in triggering and intensifying the inflammatory response in CRSwNP.

AREAS COVERED

This review undertook a comprehensive literature search across the PubMed database, Web of Science since 2000, offering an in-depth summary of the pivotal role of NPDFs in tissue remodeling and inflammatory responses in CRSwNP. Additionally, single-cell RNA sequencing data provides a deeper exploration of the heterogeneity and functional mechanisms of fibroblasts in CRSwNP. Consequently, these insights point to fibroblasts as promising therapeutic targets for effectively treating CRSwNP.

EXPERT OPINION

Current data underscore the essential role of fibroblasts in the pathogenesis of CRSwNP. Fully elucidating the specific mechanisms by which fibroblasts contribute to the disease process is crucial for developing targeted therapies. Furthermore, advancements in single-cell RNA sequencing pave the way for selectively targeting and depleting pathological fibroblast subpopulations. Despite these advancements, the clinical development of fibroblast-targeted therapies in CRSwNP remains challenging.

Are secondary bacterial pneumonia mortalities increased because of insufficient pro-resolving mediators?

Respiratory viral infections, including respiratory syncytial virus (RSV), parainfluenza viruses and type A and B influenza viruses, can have severe outcomes. Bacterial infections frequently follow viral infections, and influenza or other viral epidemics periodically have higher mortalities from secondary bacterial pneumonias. Most secondary bacterial infections can cause lung immunosuppression by fatty acid mediators which activate cellular receptors to manipulate neutrophils, macrophages, natural killer cells, dendritic cells and other lung immune cells. Bacterial infections induce synthesis of inflammatory mediators including prostaglandins and leukotrienes, then eventually also special pro-resolving mediators, including lipoxins, resolvins, protectins and maresins, which normally resolve inflammation and immunosuppression. Concurrent viral and secondary bacterial infections are more dangerous, because viral infections can cause inflammation and immunosuppression before the secondary bacterial infections worsen inflammation and immunosuppression. Plausibly, the higher mortalities of secondary bacterial pneumonias are caused by the overwhelming inflammation and immunosuppression, which the special pro-resolving mediators might not resolve.

IL-8 (CXCL8) Correlations with Psychoneuroimmunological Processes and Neuropsychiatric Conditions

Interleukin-8 (IL-8/CXCL8), an essential CXC chemokine, significantly influences psychoneuroimmunological processes and affects neurological and psychiatric health. It exerts a profound effect on immune cell activation and brain function, suggesting potential roles in both neuroprotection and neuroinflammation. IL-8 production is stimulated by several factors, including reactive oxygen species (ROS) known to promote inflammation and disease progression. Additionally, CXCL8 gene polymorphisms can alter IL-8 production, leading to potential differences in disease susceptibility, progression, and severity across populations. IL-8 levels vary among neuropsychiatric conditions, demonstrating sensitivity to psychosocial stressors and disease severity. IL-8 can be detected in blood circulation, cerebrospinal fluid (CSF), and urine, making it a promising candidate for a broad-spectrum biomarker. This review highlights the need for further research on the diverse effects of IL-8 and the associated implications for personalized medicine. A thorough understanding of its complex role could lead to the development of more effective and personalized treatment strategies for neuropsychiatric conditions.

The Inhibition Effect and Mechanism of Staurosporine Isolated from Streptomyces sp. SNC087 Strain on Nasal Polyp

This study aims to explore the potential inhibition effects of staurosporine isolated from a Streptomyces sp. SNC087 strain obtained from seawater on nasal polyps. Staurosporine possesses antimicrobial and antihypertensive activities. This research focuses on investigating the effects of staurosporine on suppressing the growth and development of nasal polyps and elucidating the underlying mechanisms involved. The experimental design includes in vitro and ex vivo evaluations to assess the inhibition activity and therapeutic potential of staurosporine against nasal polyps. Nasal polyp-derived fibroblasts (NPDFs) were stimulated with TGF-β1 in the presence of staurosporine. The levels of α-smooth muscle actin (α-SMA), collagen type-I (Col-1), fibronectin, and phosphorylated (p)-Smad 2 were investigated using Western blotting. VEGF expression levels were analyzed in nasal polyp organ cultures treated with staurosporine. TGF-β1 stimulated the production of Col-1, fibronectin, and α-SMA and was attenuated by staurosporine pretreatment. Furthermore, these inhibitory effects were mediated by modulation of the signaling pathway of Smad 2 in TGF-β1-induced NPDFs. Staurosporine also inhibits the production of VEGF in ex vivo NP tissues. The findings from this study will contribute to a better understanding of staurosporine's role in nasal polyp management and provide insights into its mechanisms of action.

A novel peptide able to reduce PLA2 activity and modulate inflammatory cytokine production

Phospholipases A2 (PLA2s) are associated with inflammatory response, performing a complex process involving, specially, cytokines. The excess of pro-inflammatory cytokines induces a chronic inflammatory response and can cause several disorders in the body. Therefore, the inhibition or regulation of cytokines' signaling pathways is a target for new treatment development strategies. Thus, this study aimed to select PLA2 inhibitor mimetic peptides through phage display technology with anti-inflammatory activity. Specific mimetic peptides were selected using BpPLA2-TXI, a PLA2 isolated from Bothrops pauloensis, as a target, and γCdcPL, a PLA2 inhibitor isolated from Crotalus durissus collilineatus, which was used as a competitor during the elution step. We selected the peptide C2PD, which seems to play a pivotal role in the modulation of IL-6, IL-1β, and IL-10 cytokines in inflammatory cells. The C2PD showed a significant reduction in PLA2 activity. Furthermore, the synthetic peptide was tested in PBMC and showed a significant down-modulation of IL-6 and IL-1β release, whereas IL-10 responses were up-regulated. Our findings suggest that this novel peptide may be a potential therapeutic candidate for the treatment of inflammatory diseases, mainly due to its anti-inflammatory properties and absence of cytotoxicity.

Role of Fibroblasts in Chronic Inflammatory Signalling in Chronic Rhinosinusitis with Nasal Polyps-A Systematic Review

Chronic rhinosinusitis with nasal polyps (CRSwNP) is an inflammatory disease of the nose and paranasal sinuses characterized by the presence of nasal polyps. The symptoms produced by the presence of nasal polyps such as nasal obstruction, nasal discharge, facial pain, headache, and loss of smell cause a worsening in the quality of life of patients. The source of the nasal polyps remains unclear, although it seems to be due to a chronic inflammation process in the sinonasal mucosa. Fibroblasts, the main cells in connective tissue, are intimately involved in the inflammation processes of various diseases; to this end, we carried out a systematic review to evaluate their inflammatory role in nasal polyps. Thus, we evaluated the main cytokines produced by nasal polyp-derived fibroblasts (NPDF) to assess their involvement in the production of nasal polyps and their involvement in different inflammatory pathways. The results of the review highlight the inflammatory role of NPDF through the secretion of various cytokines involved in the T1, T2, and T3 inflammatory pathways, as well as the ability of NPDF to be stimulated by a multitude of substances. With these findings, the fibroblast is positioned as a new potential therapeutic target in the treatment of CRSwNP.

Effects of Highly Bioavailable Curcumin Supplementation on Common Cold Symptoms and Immune and Inflammatory Functions in Healthy Japanese Subjects: A Randomized Controlled Study

This study aimed to investigate the effects of 12-week consumption of highly bioavailable curcumin (150 mg/day of Theracurmin Super [TS-P1] or Theracurmin [CR-033P]) on common cold symptoms, immune function, and inflammatory markers. A randomized, double-blind, placebo-controlled study was conducted from November 2021 to May 2022 on 99 healthy Japanese adults. Using a computerized random number generator, each subject was randomly assigned to one of the following three groups: TS-P1, CR-033P, or placebo (n = 33 per group). For 12 weeks, each group consumed the four capsules that were given to them daily. The cumulative number of days for which common cold symptoms persisted was set as the primary outcome. Immunity parameters, inflammatory parameters, liver function parameters, and physical examination results were additional outcomes. A safety assessment was also performed. Ninety-four subjects completed the study, and the per protocol set included 30 subjects in the placebo group, 32 subjects in the TS-P1 group, and 33 subjects in the CR-033P group. The cumulative number of days for which common cold symptoms persisted was significantly lower in the TS-P1 and CR-033P groups than that in the placebo group. No adverse effects were observed. Consumption of highly bioavailable curcumin, TS-P1 or CR-033P (150 mg/day), for 12 weeks reduced the number of days for which common cold symptoms persisted in healthy Japanese adults.

Multi-Omics Analysis of Lung Tissue Demonstrates Changes to Lipid Metabolism during Allergic Sensitization in Mice

Allergy and asthma pathogenesis are associated with the dysregulation of metabolic pathways. To understand the effects of allergen sensitization on metabolic pathways, we conducted a multi-omics study using BALB/cJ mice sensitized to house dust mite (HDM) extract or saline. Lung tissue was used to perform untargeted metabolomics and transcriptomics while both lung tissue and plasma were used for targeted lipidomics. Following statistical comparisons, an integrated pathway analysis was conducted. Histopathological changes demonstrated an allergic response in HDM-sensitized mice. Untargeted metabolomics showed 391 lung tissue compounds were significantly different between HDM and control mice (adjusted p < 0.05); with most compounds mapping to glycerophospholipid and sphingolipid pathways. Several lung oxylipins, including 14-HDHA, 8-HETE, 15-HETE, 6-keto-PGF1α, and PGE2 were significantly elevated in HDM-sensitized mice (p < 0.05). Global gene expression analysis showed upregulated calcium channel, G protein–signaling, and mTORC1 signaling pathways. Genes related to oxylipin metabolism such as Cox, Cyp450s, and cPla2 trended upwards. Joint analysis of metabolomics and transcriptomics supported a role for glycerophospholipid and sphingolipid metabolism following HDM sensitization. Collectively, our multi-omics results linked decreased glycerophospholipid and sphingolipid compounds and increased oxylipins with allergic sensitization; concurrent upregulation of associated gene pathways supports a role for bioactive lipids in the pathogenesis of allergy and asthma.

Current perspectives of residual ridge resorption: Pathological activation of oral barrier osteoclasts

PURPOSE

Tooth extraction is a last resort treatment for resolving pathological complications of dentition induced by infection and injury. Although the extraction wound generally heals uneventfully, resulting in the formation of an edentulous residual ridge, some patients experience long-term and severe residual ridge reduction. The objective of this review was to provide a contemporary understanding of the molecular and cellular mechanisms that may potentially cause edentulous jawbone resorption.

STUDY SELECTION

Clinical, in vivo, and in vitro studies related to the characterization of and cellular and molecular mechanisms leading to residual ridge resorption.

RESULTS

The alveolar processes of the maxillary and mandibular bones uniquely juxtapose the gingival tissue. The gingival oral mucosa is an active barrier tissue that maintains homeostasis of the internal organs through its unique barrier immunity. Tooth extraction not only generates a bony socket but also injures oral barrier tissue. In response to wounding, the alveolar bone socket initiates regeneration and remodeling through coupled bone formation and osteoclastic resorption. Osteoclasts are also found on the external surface of the alveolar bone, interfacing the oral barrier tissue. Osteoclasts in the oral barrier region are not coupled with osteoblastic bone formation and often remain active long after the completion of wound healing, leading to a net decrease in the alveolar bone structure.

CONCLUSIONS

The novel concept of oral barrier osteoclasts may provide important clues for future clinical strategies to maintain residual ridges for successful prosthodontic and restorative therapies.

Comparison of Pain Control and Inflammatory Profile in Cesarean Section Patients Treated with Multimodal Analgesia Utilizing Paracetamol and Ibuprofen

AIM: This single-blind study aimed to compare the combination of paracetamol with various doses of ibuprofen as multimodal analgesia in C-section surgery patients under spinal anesthesia. Levels of interleukin (IL)-6 and C-reactive protein (CRP) were analyzed as markers of inflammation. METHODS: Treatment groups (20 patients each) were: Group A, 750 mg paracetamol and 400 mg ibuprofen; Group B, 750 mg paracetamol and 600 mg ibuprofen; and Group C, 750 mg paracetamol and 800 mg ibuprofen. Degree of pain (movement and rest), scored using the numeric rating scale (NRS) and levels of IL-6 and CRP were assessed at various time points within 24 h of surgery. Side effects and numbers of subjects requiring rescue fentanyl administration were also recorded. RESULTS: Group C showed a rest NRS score of 1.00 ± 0.00 6 h postoperatively, compared with 2.00 ± 0.00 in Group B and 2.35 ± 0.87 in Group A. 4 h postoperatively, movement NRS scores were 1.00 ± 0.00 for Group C, compared to 3.00 ± 1.77 for Group B, and 4.85 ± 1.81 for Group A. At 12 h, IL-6 levels hours were 2.66 ± 0.04 pg/mL for Group A, 2.39 ± 0.02 pg/mL for Group B, and 2.05 ± 0.01 pg/mL for Group C. At 6 h, CRP levels were 1.18 ± 0.04 mg/L for Group A, 0.95 ± 0.01 mg/L for Group B, and 0.70 ± 0.02 mg/L for Group C. Overall, Group C showed the lowest values for all parameters analyzed, compared with other groups, and the differences were significant (p < 0.05). In addition, none of the patients in Group C required rescue fentanyl (p < 0.05), and no patients in any of the groups showed any side effects. CONCLUSION: For pain management after C-section surgery, the combination of 750 mg paracetamol and 800 mg ibuprofen yielded the best results as assessed by NRS scores, levels of IL-6 and CRP, and fentanyl rescue.

Modulation of the immune response by the Pseudomonas aeruginosa type-III secretion system

Pseudomonas aeruginosa is an opportunistic pathogen that can cause critical cellular damage and subvert the immune response to promote its survival. Among the numerous virulence factors of P. aeruginosa, the type III secretion system (T3SS) is involved in host cell pathogenicity. Using a needle-like structure, T3SS detects eukaryotic cells and injects toxins directly into their cytosol, thus highlighting its ability to interfere with the host immune response. In this mini-review, we discuss how the T3SS and bacterial effectors secreted by this pathway not only activate the immune response but can also manipulate it to promote the establishment of P. aeruginosa infections.

Antifibrosis Efficacy of Apo-9-Fucoxanthinone-Contained Sargassum horneri Ethanol Extract on Nasal Polyp: An In Vitro and Ex Vivo Organ Culture Assay

Sargassum horneri is a seaweed species with diverse bioactivities. However, its antifibrotic effects during nasal polyp (NP) formation are not clearly understood. Therefore, we investigated the inhibitory effect of S. horneri on fibrosis progression in NP-derived fibroblasts (NPDFs) and NP tissues ex vivo. NPDFs were stimulated with TGF-β1 in the presence or absence of S. horneri ethanol extract (SHE). The extracellular matrix (ECM) protein production levels, myofibroblast differentiation (α-smooth muscle actin, α-SMA), and phosphorylation of Smad 2/3 and -ERK in TGF-β1-stimulated NPDFs were investigated using western blotting. Further, the contractile activity of SHE was assessed by performing a collagen gel contraction assay. The expression levels of collagen-1, fibronectin, and α-SMA were investigated in NP organ cultures treated with SHE. TGF-β1 stimulated ECM protein expression, myofibroblast differentiation, and collagen contractile activity while these were attenuated by pretreatment with SHE. We also found antifibrotic effect of SHE on ex vivo NP tissues. The antifibrotic effects of SHE were modulated through the attenuation of Smad 2/3 and ERK signaling pathways in TGF-β1-stimulated NPDFs. In conclusion, SHE inhibited ECM protein accumulation and myofibroblast differentiation during NP remodeling. Thus, SHE may be helpful as a treatment for NP recurrence after endoscopic sinus surgery.

Correlations between Cytokine Levels, Liver Function Markers, and Neuropilin-1 Expression in Patients with COVID-19

Aim: The study evaluated the correlations between cytokine levels, liver function markers, and neuropilin-1 (NRP-1) expression in patients with COVID-19 in Egypt. The study also aimed to evaluate the accuracy sensitivity, specificity, and area under the curve (AUC) of the tested laboratory parameters in identifying COVID-19 infection and its severity. Patients and Methods: Fifty healthy subjects and 100 confirmed patients with COVID-19 were included in this study. COVID-19 patients were separated into two groups based on the severity of their symptoms. Serum ALT, AST, albumin, C-reactive protein (CRP), interleukin (IL)-1β, IL-4, IL-6, IL-18, IL-35, prostaglandin E2 (PGE2), and thromboxane A2 (TXA2) were estimated. We measured the gene expression for nuclear factor-kappa B p50 (NF-κB p50) and nuclear factor-kappa B p65 (NF-κB p65) and NRP-1 in blood samples using quantitative real-time polymerase chain reaction (qRT-PCR). AUC and sensitivity and specificity for cytokine levels and NF-κB p50 and NF-κB p65 and NRP-1 in identifying COVID-19 infection were also determined in both moderate and severe patient groups using receiver-operating characteristic curve (ROC) analysis. Results: All patients with COVID-19 showed higher serum activities of liver enzymes, levels of CRP, IL-1β, IL-4, IL-6, IL-18, IL-35 PGE2, and TXA2, and mRNA expression of NF-κB p50, NF-κB p65, and NRP-1 than healthy subjects. The severe group exhibited a significant increase in serum ALT, AST and IL-6 and a significant decrease in albumin, IL-1β, TXA2, and NF-κB p65 levels compared to the moderate group. In all patients (moderate and severe), all cytokines were positively correlated with NF-κB p50, NF-κB p65 and NRP-1 expression levels. Serum ALT and AST were positively correlated with CRP, cytokines (IL-4, IL-6, IL-18, IL-35 and TXA2), and NF-κB p50 and NF-κB p65 expression levels in both moderate and severe groups. They were also positively correlated with serum IL-1β level in the severe COVID-19 patient group and with NRP-1 expression in the moderate group. Using the logistic regression analysis, the most important four statistically significant predictors associated with COVID-19 infection in the study were found to be IL-6, TAX2, NF-κB p50 and NF-κB p65. ROC analysis of these variables revealed that three of them had AUC > 0.8. In moderate cases, AUC of the serum TXA2 level and NF-κB p65 expression were 0.843 (95% CI 0.517−0.742, p < 0.001) and 0.806 (95% CI 0.739−0.874, p < 0.001), respectively. In the severe group, AUC of serum IL-6 level was 0.844 (95% CI 0.783−0.904, p < 0.001). Moreover, Il-6 had a sensitivity of 100% in both moderate and severe groups. Conclusions: This study concluded that liver injury in patients with COVID-19 may be strongly attributed to the cytokines storm, especially IL-6, which was positively correlated to NF-κB p50, NF-κB p65 and NRP-1 mRNA expression levels. Moreover, ROC analysis revealed that IL-6, TXA2, and NF-κB p65 could be useful in predicting the possibility of infection with COVID-19, and IL-6 could be of possible significance as a good predictor of the severity and disease progress. However, RT-qPCR for SARS-CoV-2 detection is essential to confirm infection and further clinical studies are required to confirm this elucidation.

Expression of Matrix Metalloproteinases and Their Tissue Inhibitors in Chronic Rhinosinusitis With Nasal Polyps: Etiopathogenesis and Recurrence

Chronic rhinosinusitis with nasal polyps is a multifactorial disease of the nasal and paranasal sinus mucosa and it includes, as comorbidities, anatomic and morphologic alterations, allergic rhinitis, and immunologic diseases. We investigated matrix metalloproteinases (MMP-2, MMP-7, and MMP-9) and their tissue inhibitors (TIMP-1 and TIMP-2) concentration in different etiopathogenetical groups of patients with nasal polyposis (NP) in relation to recurrence after sinonasal surgery. The study group consisted of 45 patients with NP (those with allergic rhinitis, nonallergic rhinitis and asthma or nonallergic rhinitis, and obstruction of osteomeatal complex [OMC]) who underwent endonasal sinus surgery. We also collected 10 patients who underwent septoplasty as control. Immunohistochemistry of nasal mucosa fragments, Western blotting, and polymerase chain reaction analysis showed increased MMPs levels (MMP-9 more than MMP-2 and MMP-7) and decreased tissue inhibitors of MMPs levels (TIMP-1 less than TIMP-2), in patients with chronic rhinosinusitis with nasal polyps compared with control group, in particular in patients with nonallergic rhinitis and asthma compared to those with allergic rhinitis and nonallergic rhinitis and obstruction of OMC. We observed a higher risk of recurrence in patients with nonallergic rhinitis and asthma than in those with allergic rhinitis and nonallergic rhinitis and obstruction of OMC after 36 months from surgery. In this research, we evaluated pathogenesis of NP related to MMPs and their inhibitors concentrations in polypoid tissue.

Caffeic Acid Modulates Processes Associated with Intestinal Inflammation

Caffeic acid is one of the most abundant hydroxycinnamic acids in fruits, vegetables, and beverages. This phenolic compound reaches relevant concentrations in the colon (up to 126 µM) where it could come into contact with the intestinal cells and exert its anti-inflammatory effects. The aim of this investigation was to study the capacity of caffeic acid, at plausible concentrations from an in vivo point of view, to modulate mechanisms related to intestinal inflammation. Consequently, we tested the effects of caffeic acid (50–10 µM) on cyclooxygenase (COX)-2 expression and prostaglandin (PG)E₂, cytokines, and chemokines (IL-8, monocyte chemoattractant protein-1 -MCP-1-, and IL-6) biosynthesis in IL-1β-treated human myofibroblasts of the colon, CCD-18Co. Furthermore, the capacity of caffeic acid to inhibit the angiotensin-converting enzyme (ACE) activity, to hinder advanced glycation end product (AGE) formation, as well as its antioxidant, reducing, and chelating activity were also investigated. Our results showed that (i) caffeic acid targets COX-2 and its product PGE₂ as well as the biosynthesis of IL-8 in the IL-1β-treated cells and (ii) inhibits AGE formation, which could be related to (iii) the high chelating activity exerted. Low anti-ACE, antioxidant, and reducing capacity of caffeic acid was also observed. These effects of caffeic acid expands our knowledge on anti-inflammatory mechanisms against intestinal inflammation.

Histamine Induced Production of Chemokine CXCL8 Through H1R/PLC and NF-κB Signaling Pathways in Nasal Fibroblasts

Background and Objectives: Histamine has been suggested to play an important role during allergic and inflammatory reactions, affecting allergic rhinitis and chronic rhinosinusitis. CXCL8 is a pro-inflammatory chemokine and a critical factor that causes many airway inflammatory diseases including allergic rhinitis and chronic rhinosinusitis.Materials and Method: Histamine cytotoxicity was measured by MTT assay. Real-time polymerase chain reaction was used to identify histamine type 1 receptor in nasal fibroblasts. The fibroblasts were then treated with histamine with or without a histamine type 1 receptor antagonist and the CXCL8 protein was assessed using an enzyme-linked immunosorbent assay (ELISA). The downstream signaling molecules, including phospholipase C and phospho-p50, were evaluated by western blot and immunofluorescent staining.Results: Histamine had no significant cytotoxic effect until the concentration reached 1,000 μM. Histamine type 1 receptor mRNA was expressed in nasal fibroblasts. CXCL8 protein expression level was significantly increased following histamine stimulation. However, the expression level of CXCL8 decreased when phospholipase C was inhibited by U73122. Histamine increased phospho-p50 expression as seen in western blot results. The BAY11-7082, NF-κB inhibitor significantly reduced CXCL8 production in histamine-stimulated nasal fibroblasts.Conclusion: Histamine can induce the production of NF-κB controlled-chemokine CXCL8 by nasal fibroblasts, which supports a role for histamine in upper airway inflammatory diseases.

Non-steroidal anti-inflammatory drugs, prostaglandins, and COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of the novel coronavirus disease 2019 (COVID-19), a highly pathogenic and sometimes fatal respiratory disease responsible for the current 2020 global pandemic. Presently, there remains no effective vaccine or efficient treatment strategies against COVID-19. Non-steroidal anti-inflammatory drugs (NSAIDs) are medicines very widely used to alleviate fever, pain, and inflammation (common symptoms of COVID-19 patients) through effectively blocking production of prostaglandins (PGs) via inhibition of cyclooxyganase enzymes. PGs can exert either proinflammatory or anti-inflammatory effects depending on the inflammatory scenario. In this review, we survey the potential roles that NSAIDs and PGs may play during SARS-CoV-2 infection and the development and progression of COVID-19. LINKED ARTICLES: This article is part of a themed issue on The Pharmacology of COVID-19. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.21/issuetoc.

Expression of trophoblast derived prostaglandin E2 receptor 2 (EP2) is reduced in patients with recurrent miscarriage and EP2 regulates cell proliferation and expression of inflammatory cytokines

BACKGROUD

Prostaglandin E2 (PGE2), an inflammatory mediator, modulates cytokines, regulates immune responses in reproductive processes and stimulates inflammatory reactions via the prostaglandin E2 receptor 2 (EP2). However, the regulatory effects of EP2 signaling on trophoblasts and its role in unexplained recurrent miscarriage (uRM) remains unclear.

PATIENTS AND METHODS

A total of 19 placentas from patients with a history of more than two consecutive pregnancy losses of unknown cause (uRM group) and placentas of 19 healthy patients following a legal termination of their pregnancy were used for PGE2 receptor (EP1, EP2 and EP4) expression analyses via immunohistochemistry. Double immunofluorescence was also used to identify EP2 expressing cells in the decidua. Finally, HTR-8/SVneo cells were used to clarify the role of EP2 in in vitro experiments.

RESULTS

The expression of EP2 and EP4 was found to be reduced in the syncytiotrophoblast and decidua of uRM patients. A selective EP2 receptor antagonist (PF-04,418,948) reduced the proliferation and secretion of ß-hCG, inhibited interleukin -6 (IL-6) and interleukin-8 (IL-8) and up-regulated the production of the tumor necrosis factor-α (TNF-α) and plasminogen activator inhibitor type 1 (PAI-1) in HTR-8/SVneo cells in vitro.

CONCLUSION

PGE2-EP2 signaling pathway may represent a novel therapy option for uRM. The involvement of EP2 in uRM acts perhaps via inflammatory cytokines and indicates that the PGE2-EP2 signaling pathway might represent an unexplored etiology for uRM.

Human mesenchymal stem cells derived from umbilical cord and bone marrow exert immunomodulatory effects in different mechanisms

BACKGROUND

Mesenchymal stem cells (MSCs) are an attractive tool to treat graft-versus-host disease because of their unique immunoregulatory properties. Although human bone marrow-derived MSCs (BM-MSCs) were the most widely used MSCs in cell therapy until recently, MSCs derived from human umbilical cords (UC-MSCs) have gained popularity as cell therapy material for their ethical and noninvasive collection.

AIM

To investigate the difference in mechanisms of the immunosuppressive effects of UC-MSCs and BM-MSCs.

METHODS

To analyze soluble factors expressed by MSCs, such as indolamine 2,3-dioxygenase, cyclooxygenase-2, prostaglandin E2 and interleukin (IL)-6, inflammatory environments in vitro were reconstituted with combinations of interferon-gamma (IFN-γ), tumor necrosis factor alpha and IL-1β or with IFN-γ alone. Activated T cells were cocultured with MSCs treated with indomethacin and/or anti-IL-10. To assess the ability of MSCs to inhibit T helper 17 cells and induce regulatory T cells, induced T helper 17 cells were cocultured with MSCs treated with indomethacin or anti-IL-10. Xenogeneic graft-versus-host disease was induced in NOG mice (NOD/Shi-scid/IL-2Rγ^null) and UC-MSCs or BM-MSCs were treated as cell therapies.

RESULTS

Our data demonstrated that BM-MSCs and UC-MSCs shared similar phenotypic characteristics and immunomodulation abilities. BM-MSCs expressed more indolamine 2,3-dioxygenase after cytokine stimulation with different combinations of IFN-γ, tumor necrosis factor alpha-α and IL-1β or IFN-γ alone. UC-MSCs expressed more prostaglandin E2, IL-6, programmed death-ligand 1 and 2 in the in vitro inflammatory environment. Cyclooxygenase-2 and IL-10 were key factors in the immunomodulatory mechanisms of both MSCs. In addition, UC-MSCs inhibited more T helper 17 cells and induced more regulatory T cells than BM-MSCs. UC-MSCs and BM-MSCs exhibited similar effects on attenuating graft-versus-host disease.

CONCLUSION

UC-MSCs and BM-MSCs exert similar immunosuppressive effects with different mechanisms involved. These findings suggest that UC-MSCs have distinct immunoregulatory functions and may substitute BM-MBSCs in the field of cell therapy.

Potential benefits and risks of omega-3 fatty acids supplementation to patients with COVID-19

Studies have shown that infection, excessive coagulation, cytokine storm, leukopenia, lymphopenia, hypoxemia and oxidative stress have also been observed in critically ill Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) patients in addition to the onset symptoms. There are still no approved drugs or vaccines. Dietary supplements could possibly improve the patient's recovery. Omega-3 fatty acids, specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), present an anti-inflammatory effect that could ameliorate some patients need for intensive care unit (ICU) admission. EPA and DHA replace arachidonic acid (ARA) in the phospholipid membranes. When oxidized by enzymes, EPA and DHA contribute to the synthesis of less inflammatory eicosanoids and specialized pro-resolving lipid mediators (SPMs), such as resolvins, maresins and protectins. This reduces inflammation. In contrast, some studies have reported that EPA and DHA can make cell membranes more susceptible to non-enzymatic oxidation mediated by reactive oxygen species, leading to the formation of potentially toxic oxidation products and increasing the oxidative stress. Although the inflammatory resolution improved by EPA and DHA could contribute to the recovery of patients infected with SARS-CoV-2, Omega-3 fatty acids supplementation cannot be recommended before randomized and controlled trials are carried out.

Simple hypertrophic tonsils have more active innate immune and inflammatory responses than hypertrophic tonsils with recurrent inflammation in children

Background

Tonsil hypertrophy has negative impact on children’s health, but its pathogenesis remains obscure despite the fact that numerous bacteriological studies have been carried out. Understanding the innate immune and inflammatory states of hypertrophic tonsils with different clinical manifestations is of great significance for defining the pathogenesis of tonsil hypertrophy and establishing treatment strategies. The present study was undertaken to examine the characteristics of innate immunity and inflammation in children with hypertrophic palatine tonsils and different clinical manifestations.

Methods

Tonsil tissues were surgically removed from the patients and classified based on the patients’ clinical manifestations. The patients were divided into three groups: 1) Control group; 2) Tonsil Hypertrophy (TH) group; and 3) Tonsil Hypertrophy combined with Recurrent Infection (TH + RI) group. The immune and inflammatory statuses of these tissues were characterized using qRT-PCR and ELISA methods.

Results

Viral protein 1 (VP1) was highly expressed in TH group, but not in TH + RI group. In TH group, elevated expression was observed in the innate immune mediators, including retinoic acid-inducible gene I (RIG-I), interferon alpha (IFN-α), mitochondrial antiviral-signaling protein (MAVS), NLR family pyrin domain containing 3 (NLRP3), toll-like receptor (TLR) 4 and TLR7. Consistent with the innate immune profile, the expression of inflammatory markers (IL-1β, NF-κB and IL-7) was also significantly elevated in TH group. Meanwhile, the COX-2/PGE2/EP4 signaling pathway was found to be involved in the inflammatory response and the formation of fibroblasts.

Conclusions

Innate immune and inflammatory responses are more active in simple hypertrophic tonsils, rather than hypertrophic tonsils with recurrent inflammation. A local relative immune deficiency in the hypertrophic tonsils may be a causative factor for recurrent tonsillitis in TH + RI. These differences, together with the patient’s clinical manifestations, suggest that tonsillar hypertrophy might be regulated by diverse immune and/or inflammatory mechanism through which novel therapeutic strategies might be created.

Effect of fluticasone propionate on human nasal fibroblasts exposed to urban particulate matter

OBJECTIVE

Particulate matter (PM), which contains organic compounds and toxic metals, is the major cause of air pollution. PM enters the body, causing various health problems. Although the effects of PM on the lower respiratory tract have been extensively investigated, the effects on the upper respiratory tract (including the nasal cavity) require further evaluation. To investigate the effect of fluticasone propionate (FP) on nasal fibroblasts exposed to UPM.

METHODS

Samples of inferior turbinate tissue were obtained from six patients. The fibroblasts isolated from these samples were exposed to UPM and/or FP. The expression of interleukin (IL)-6, CXC chemokine ligand (CXCL) 1, IL-1β, and tumour necrosis factor-alpha (TNF-α) in nasal fibroblasts was analysed using real-time PCR and enzyme-linked immunosorbent assays. The protein levels of nuclear factor kappa B (NF-κB) and signal transducer and activator of transcription 3 (STAT3) were analysed by western blotting.

RESULTS

FP reversed the UPM-induced reduction in cell viability. The mRNA and protein levels of IL-6, CXCL1, IL-1β, and TNF-α were significantly increased by UPM. FP reversed the UPM-induced increases in the protein levels of NF-κB and phosphorylated-STAT3 in a dose-dependent manner. In addition, TNF-α, an inducer of NF-κB, reversed the FP-induced reduction in the levels of signalling molecules.

CONCLUSION

UPM induces the expression of IL-6, CXCL1, IL-1β, and TNF-α in nasal fibroblasts and this effect is reversed by FP via the STAT3 and NF-κB signalling pathways. These results suggest that FP has therapeutic potential for nasal diseases related to UPM, such as allergic and chronic rhinitis.

Activation of the Nrf2/HO-1 pathway by curcumin inhibits oxidative stress in human nasal fibroblasts exposed to urban particulate matter

BACKGROUND

Particulate matter (PM) can cause various negative acute and chronic diseases of the respiratory system, including the upper airways. Curcumin has been reported to have anti-inflammatory and anti-oxidative effects; therefore, we investigated the effects of curcumin on nasal fibroblasts exposed to urban PM (UPM).

METHODS

Samples of inferior turbinate tissue were obtained from six patients. Flow cytometry was used to assess the levels of reactive oxygen species (ROS) following the treatment of nasal fibroblasts with UPM and/or curcumin. We evaluated the effects of UPM and/or curcumin on the expression of phosphorylated ERK, Nrf2, HO-1, and SOD2 in fibroblasts by Western blotting.

RESULTS

When UPM was applied to nasal fibroblasts, ROS production was significantly increased in a dose-dependent manner. UPM-exposed fibroblasts caused the activation of ERK to increase HO-1 expression and decrease SOD2 expression. Treatment with curcumin reduced the UPM-mediated increase in ROS; this decrease in ROS occurred in a dose-dependent manner. The UPM-induced activation of ERK was inhibited by curcumin. Nrf2 production was also promoted to increase the expression of HO-1 and SOD2 by curcumin.

CONCLUSION

Curcumin reduced ROS production caused by UPM in human nasal fibroblasts in a dose-dependent manner, suggesting that curcumin has anti-oxidative effects and may be useful in the treatment of nasal diseases caused by UPM, such as allergic and chronic rhinitis.

Proinflammatory Effects of IL-1β Combined with IL-17A Promoted Cartilage Degradation and Suppressed Genes Associated with Cartilage Matrix Synthesis In Vitro

Combinations of IL-1β and other proinflammatory cytokines reportedly promote the severity of arthritis. We aimed to investigate the effects of IL-1β combined with IL-17A on cartilage degradation and synthesis in in vitro models. Cartilage explant degradation was determined using sulfated glycosaminoglycans (S-GAGs) levels, matrix metalloproteinase (MMP13) gene expression, uronic acid, and collagen contents. Cell morphology and accumulation of proteoglycans were evaluated using hematoxylin-eosin and safranin O staining, respectively. In the pellet culture model, expressions of cartilage-specific anabolic and catabolic genes were evaluated using real-time qRT-PCR. Early induction of MMP13 gene expression was found concomitantly with significant S-GAGs release. During the prolonged period, S-GAGs release was significantly elevated, while MMP-13 enzyme levels were persistently increased together with the reduction of the cartilaginous matrix molecules. The pellet culture showed anabolic gene downregulation, while expression of the proinflammatory cytokines, mediators, and MMP13 genes were elevated. After cytokine removal, these effects were restored to nearly basal levels. This study provides evidence that IL-1β combined with IL-17A promoted chronic inflammatory arthritis by activating the catabolic processes accompanied with the suppression of cartilage anabolism. These suggest that further applications, which suppress inflammatory enhancers, especially IL-17A, should be considered as a target for arthritis research and therapy.

The role of myeloid-derived suppressor cells in endometrial cancer displaying systemic inflammatory response: clinical and preclinical investigations

Systemic inflammatory responses including thrombocytosis, leukocytosis, or neutrophilia have gained attention as prognostic indicators in patients with various solid malignancies.current study, we aimed to investigate the clinical implications and underlying biological mechanism of the systemic inflammatory response in endometrial cancer. Clinical data from 900 patients with endometrial cancer were analyzed to investigate the association between pretreatment leukocytosis, thrombocytosis, and treatment outcome. Clinical samples, endometrial cancer cell lines, and a mouse model of endometrial cancer were used to examine the mechanisms responsible for systemic inflammatory response in endometrial cancer, focusing on the role of tumor-derived granulocyte colony-stimulating factor (G-CSF) and MDSCs. Then, we showed that pretreatment concurrent leukocytosis and thrombocytosis is associated with significantly shorter survival and decreased chemosensitivity among patients with endometrial cancer. In vitro and in vivo experiments revealed that tumor-derived G-CSF and G-CSF-mediated IL-6 production from the tumor microenvironment are involved in the development of leukocytosis and thrombocytosis in patients with endometrial cancer. Moreover, increased tumor-infiltrating MDSCs induced by tumor-derived G-CSF, MDSC-mediated T cell suppression, and MDSC-mediated cancer stem cell induction are responsible for progression and chemoresistance in this type of endometrial cancer. MDSC depletion using an anti-Gr-1 neutralizing antibody or inhibition of MDSC activity by celecoxib inhibited tumor growth and enhanced chemosensitivity in endometrial cancer displaying concurrent leukocytosis and thrombocytosis. In conclusion, Pretreatment concurrent leukocytosis and thrombocytosis are associated with significantly shorter survival and decreased chemosensitivity among patients with endometrial cancer. Combining MDSC-targeting treatments with current standard chemotherapies might have therapeutic efficacy for these patients.

Role of Apple Phytochemicals, Phloretin and Phloridzin, in Modulating Processes Related to Intestinal Inflammation

Plant-derived food consumption has gained attention as potential intervention for the improvement of intestinal inflammatory diseases. Apple consumption has been shown to be effective at ameliorating intestinal inflammation symptoms. These beneficial effects have been related to (poly)phenols, including phloretin (Phlor) and its glycoside named phloridzin (Phldz). To deepen the modulatory effects of these molecules we studied: i) their influence on the synthesis of proinflammatory molecules (PGE2, IL-8, IL-6, MCP-1, and ICAM-1) in IL-1β-treated myofibroblasts of the colon CCD-18Co cell line, and ii) the inhibitory potential of the formation of advanced glycation end products (AGEs). The results showed that Phlor (10-50 μM) decreased the synthesis of PGE2 and IL-8 and the formation of AGEs by different mechanisms. It is concluded that Phlor and Phldz, compounds found exclusively in apples, are positively associated with potential beneficial effects of apple consumption.

Reactive Oxygen Species Are Necessary for Bleomycin A5-Induced Apoptosis and Extracellular Matrix Elimination of Nasal Polyp-Derived Fibroblasts

BACKGROUND:

The pathology of chronic rhinosinusitis with nasal polyp (CRSwNP) is characterized by the infiltration of a large number of fibroblasts, resulting in extracellular matrix (ECM) deposition. Intralesional bleomycin A5 (BLE) injection has proved to be effective and safe, providing a novel treatment for CRSwNP. However, the mechanism is not clearly understood.

OBJECTIVES:

The aim of this study is to explore the possible mechanism of BLE-induced apoptosis in nasal polyp-derived fibroblasts (NPDFs).

MATERIAL AND METHODS:

Dichloro-dihydro-fluorescein diacetate probe, cell migration assays, and cell cycle analysis were used to detect the growth characteristics and basal reactive oxygen species (ROS) traits of NPDFs. Annexin V/propidium iodide and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay was used to detect BLE-induced apoptosis. As a control, the antioxidant glutathione (GSH) was used to abrogate ROS induced by BLE. Western blot analysis was used to evaluate the effects of BLE on apoptosis and the ECM proteins of NPDFs.

RESULTS:

The results showed that NPDFs had more active growth characteristics and higher basal ROS levels than normal nasal mucosa fibroblasts (NMFCs). NPDFs were more sensitive to BLE-induced apoptosis and ROS accumulation. GSH abrogation inhibits BLE-induced ECM degradation and apoptosis in NPDFs through a mitochondrial-mediated pathway.

CONCLUSIONS:

BLE induced NPDF apoptosis and ECM degradation through a mitochondrial-mediated pathway and in a ROS-dependent manner.

Vibration enhances PGE2 , IL-6, and IL-8 expression in compressed hPDL cells via cyclooxygenase pathway

BACKGROUND

Although vibration combined with orthodontic force may accelerate orthodontic tooth movement, little is known about the mechanisms that regulate the associated cellular responses. The goal of this study was to investigate whether mechanical vibration combined with compressive force regulates cyclooxygenase (COX)-2/prostaglandin E2 (PGE₂ ) and interleukin (IL)-6 and IL-8 messenger RNA (mRNA) and protein expression in human periodontal ligament (hPDL) cells via the COX pathway.

METHODS

The primary cultured hPDL cells were exposed to mechanical vibration, compressive force or a combination of both mechanical vibration and compressive force at 24, 48, and 72 hours. The COX-2, IL-6, IL-8, receptor activator of nuclear factor kappa-Β ligand (RANKL), and osteoprotegrin (OPG) mRNA expressions were determined using quantitative real-time polymerase chain reaction (qPCR). The PGE₂ , IL-6, and IL-8 protein expressions were quantified by enzyme-linked immunosorbent assay (ELISA). To demonstrate whether the expression of PGE₂ , IL-6, and IL-8 was in the COX-dependent pathway, the hPDL cells were treated with indomethacin. To determine whether PGE₂ stimulated the hPDL cells to express IL-6 and IL-8, exogenous PGE₂ was added to the culture media.

RESULTS

The combination of mechanical vibration and compressive force synergistically upregulated RANKL/OPG, COX-2/PGE₂ , IL-6 and IL-8 mRNA, and protein expression. The indomethacin significantly attenuated the increases of PGE₂ , IL-6, and IL-8 expression in cells stimulated with compressive force or mechanical vibration combined with compressive force. In addition, exogenous PGE₂ increased IL-6 and IL-8 mRNA and protein expressions in hPDL cells.

CONCLUSION

Mechanical vibration may enhance alveolar bone resorption at the compression side during orthodontic tooth movement via a mechanism involving the cyclooxygenase pathway.

The effect of urban particulate matter on cultured human nasal fibroblasts

BACKGROUND

Exposure to urban particulate matter (UPM) has been linked to aggravation of various health problems. Although the effects of UPM on the lower respiratory tract have been extensively studied, more research is required on the impact of UPM on the upper respiratory tract and the underlying mechanisms. Thus, we investigated the cytotoxic effects of UPM on cultured human nasal fibroblasts, the underlying signaling pathways involved, and changes in cytokine levels.

METHODS

Human turbinate tissue specimens were collected during partial turbinectomies performed on 6 patients, and then cultured. The effect of UPM on nasal fibroblast viability was explored. Real-time reverse transcription-polymerase chain reaction was used to measure the mRNA levels of genes encoding cytokines and chemokines (interleukin [IL]-4, IL-6, IL-8, and tumor necrosis factor-α) before and after 24 hours of UPM treatment. Enzyme-linked immunosorbent assays were employed to measure IL-6 and IL-8 levels. The status of the p38 and nuclear factor (NF)-κB signaling pathways was analyzed by Western blotting.

RESULTS

UPM reduced cell viability in a dose-dependent manner and increased IL-6 and IL-8 expression at both the mRNA and protein levels. UPM induced the phosphorylation of p38 and NF-κB p65; inhibitors of the actions of these proteins repressed phosphorylation and the expression of IL-6 and IL-8.

CONCLUSION

UPM induced IL-6 and IL-8 expression by fibroblasts via p38 and NF-κB classical signaling, suggesting that UPM can induce or aggravate allergic and/or chronic rhinitis.

Regular nicotine intake increased tooth movement velocity, osteoclastogenesis and orthodontically induced dental root resorptions in a rat model

Orthodontic forces have been reported to significantly increase nicotine-induced periodontal bone loss. At present, however, it is unknown, which further (side) effects can be expected during orthodontic treatment at a nicotine exposure corresponding to that of an average European smoker. 63 male Fischer344 rats were randomized in three consecutive experiments of 21 animals each (A/B/C) to 3 experimental groups (7 rats, 1/2/3): (A) cone-beam-computed tomography (CBCT); (B) histology/serology; (C) reverse-transcription quantitative real-time polymerase chain reaction (RT-qPCR)/cotinine serology—(1) control; (2) orthodontic tooth movement (OTM) of the first and second upper left molar (NiTi closed coil spring, 0.25 N); (3) OTM with 1.89 mg·kg⁻¹ per day s.c. of L(−)-nicotine. After 14 days of OTM, serum cotinine and IL-6 concentration as well as orthodontically induced inflammatory root resorption (OIIRR), osteoclast activity (histology), orthodontic tooth movement velocity (CBCT, within 14 and 28 days of OTM) and relative gene expression of known inflammatory and osteoclast markers were quantified in the dental-periodontal tissue (RT–qPCR). Animals exposed to nicotine showed significantly heightened serum cotinine and IL-6 levels corresponding to those of regular European smokers. Both the extent of root resorption, osteoclast activity, orthodontic tooth movement and gene expression of inflammatory and osteoclast markers were significantly increased compared to controls with and without OTM under the influence of nicotine. We conclude that apart from increased periodontal bone loss, a progression of dental root resorption and accelerated orthodontic tooth movement are to be anticipated during orthodontic therapy, if nicotine consumption is present. Thus patients should be informed about these risks and the necessity of nicotine abstinence during treatment.

Anti-inhibitory potential of an ethanolic extract of Distromium decumbens on pro-inflammatory cytokine production in Pseudomonas aeruginosa lipopolysaccharide-stimulated nasal polyp-derived fibroblasts

Marine algae are rich sources of biologically active compounds that may present useful leads in the development of pharmaceuticals, nutraceuticals, and functional foods. The main aim of this study was to identify the possible anti-inflammatory effects of Distromium decumbens in nasal polyp-derived fibroblasts (NPDFs) and its associated mechanism of action. NPDFs were stimulated by Pseudomonas aeruginosa lipopolysaccharide (PA-LPS) and treated with an ethanolic extract of Distromium decumbens (DDE). The production of interleukin-6 (IL-6) and IL-8 in the supernatant, the phosphorylation of mitogen-activated protein kinase (MAPK) molecules [extracellular signal-related kinase 1/2 (ERK1/2), c-Jun N-terminal kinase and p38 MAPK] and Akt, and the activation of nuclear factor-κB (NF-κB) were assayed in the PA-LPS-stimulated NPDFs untreated or treated with DDE. The expression levels of IL-6 and IL-8 in PA-LPS-exposed NPDFs were detected using enzyme-linked immunosorbent assays. The mechanisms by which DDE regulates cellular signaling cascades were investigated using electrophoretic mobility shift assays and western blot analysis. Functional validation was performed by measuring the inhibitory effects of DDE on neutrophil migration in vitro. DDE reduced the expression of IL-6 and IL-8 stimulated by PA-LPS in NPDFs. The activation of ERK1/2, Akt and NF-κB by PA-LPS was inhibited by DDE. Inhibitors of ERK1/2, Akt and NF-κB inhibited the expression of IL-6 and IL-8. In addition, DDE significantly attenuated PA-LPS-induced migration of differentiated HL-60 cells. The present findings suggest that DDE potently inhibits inflammation through the ERK1/2, Akt and NF-κB signaling pathways in NPDFs.

Activation of PGE2/EP2 and PGE2/EP4 signaling pathways positively regulate the level of PD-1 in infiltrating CD8+ T cells in patients with lung cancer

The present study aimed to identify the level of programmed death-1 (PD-1) expression in infiltrating cluster of differentiation (CD)4⁺ and CD8⁺ T cells isolated from lung cancer tissues, and investigated whether the level of PD-1 expression may be directly regulated by lung cancer cells via prostaglandin E2 (PGE2)-associated signaling pathways in patients with lung cancer. A total of 75 patients with lung cancer were enrolled in the present study. The percentage of infiltrating CD4⁺ and CD8⁺ T cells was determined by flow cytometry. ELISA was performed to evaluate the concentration of PGE2 in lung cancer tissue homogenate. The correlation between PGE2 and PD-1 expression levels in CD8⁺ T cells was assessed by Spearman's rank correlation test. The expression levels of PD-1 and PGE2 receptors were determined by reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. The level of PD-1 expression in infiltrating CD8⁺ T cells was gradually increased as the stage of lung cancer increased. The level of PD-1 expression was also positively associated with the concentration of PGE2 in lung cancer tissues. Furthermore, the level of PD-1 expression was closely associated with the PGE2/EP2 and PGE2/EP4 signaling pathways. The activation of PGE2-associated EP2- and EP4-pathways may positively regulate the level of PD-1 in infiltrating CD8⁺ T cells, which results in immune tolerance in the lung cancer microenvironment.

TNF-α promotes survival and migration of MSCs under oxidative stress via NF-κB pathway to attenuate intimal hyperplasia in vein grafts

The oxidative stress caused by endothelial injury is involved in intimal hyperplasia (IH) in vein grafts. Mesenchymal stem cells (MSCs) can home to injured intima and promote endothelial repair. However, MSC apoptosis is increased accompanied by decreased functional activity under oxidative stress. Thus, we investigate whether tumour necrosis factor‐α (TNF‐α) can promote the survival and activity of MSCs under oxidative stress to reduce IH more effectively, and establish what role the NF‐κB pathway plays in this. In this study, we preconditioned MSCs with TNF‐α (^{TNF‐α‐PC}MSCs) for 24 hrs and measured the activation of the IKK/NF‐κB pathway. EdU and transwell assays were performed to assess proliferation and migration of ^{TNF‐α‐PC}MSCs. Apoptosis and migration of ^{TNF‐α‐PC}MSCs were evaluated in conditions of oxidative stress by analysis of the expression of Bcl‐2 and CXCR4 proteins. ^{TNF‐α‐PC}MSCs were transplanted into a vein graft model, so that cell homing could be tracked, and endothelial apoptosis and IH of vein grafts were measured. The results demonstrated that TNF‐α promotes proliferation and migration of MSCs. Furthermore, survival and migration of ^{TNF‐α‐PC}MSCs under oxidative stress were both enhanced. A greater number of MSCs migrated to the intima of vein grafts after preconditioning with TNF‐α, and the formation of neointima was significantly reduced. These effects could be partially abolished by IKK XII (NF‐κB inhibitor). All these results indicate that preconditioning with TNF‐α can promote survival and migration of MSCs under oxidative stress via the NF‐κB pathway and thus attenuate IH of vein grafts.

Phospholipase A2-activating protein is associated with a novel form of leukoencephalopathy

Leukoencephalopathies are a group of white matter disorders related to abnormal formation, maintenance, and turnover of myelin in the central nervous system. These disorders of the brain are categorized according to neuroradiological and pathophysiological criteria. Herein, we have identified a unique form of leukoencephalopathy in seven patients presenting at ages 2 to 4 months with progressive microcephaly, spastic quadriparesis, and global developmental delay. Clinical, metabolic, and imaging characterization of seven patients followed by homozygosity mapping and linkage analysis were performed. Next generation sequencing, bioinformatics, and segregation analyses followed, to determine a loss of function sequence variation in the phospholipase A₂-activating protein encoding gene (PLAA). Expression and functional studies of the encoded protein were performed and included measurement of prostaglandin E₂ and cytosolic phospholipase A₂ activity in membrane fractions of fibroblasts derived from patients and healthy controls. Plaa-null mice were generated and prostaglandin E₂ levels were measured in different tissues. The novel phenotype of our patients segregated with a homozygous loss-of-function sequence variant, causing the substitution of leucine at position 752 to phenylalanine, in PLAA, which causes disruption of the protein's ability to induce prostaglandin E₂ and cytosolic phospholipase A₂ synthesis in patients' fibroblasts. Plaa-null mice were perinatal lethal with reduced brain levels of prostaglandin E₂ The non-functional phospholipase A₂-activating protein and the associated neurological phenotype, reported herein for the first time, join other complex phospholipid defects that cause leukoencephalopathies in humans, emphasizing the importance of this axis in white matter development and maintenance.

Diesel Exhaust Particles Upregulate Interleukins IL-6 and IL-8 in Nasal Fibroblasts

Background

Diesel exhaust particles (DEP) are a major source of air pollution. Nasal fibroblasts are known to produce various cytokines and chemokines. The aim of this study was to evaluate DEP-induced cytokines and chemokines in nasal fibroblasts and to identify the signaling pathway involved.

Methods

A cytokine and chemokine array performed after stimulation of nasal fibroblasts with DEP revealed that levels of IL-6 and IL-8 were increased most significantly among various cytokines and chemokines. RT—PCR and ELISA were used to determine the mRNA and protein expression levels of IL-6 and IL-8. Signaling pathways of p-38, Akt, and NF-κB were analyzed by western blotting, luciferase assay, and ELISA. Organ cultures of nasal interior turbinate were also developed to demonstrate the ex vivo effect of DEP on the expression of IL-6 and IL-8 and the associated signaling pathway.

Results

DEP increased the expressions of IL-6 and IL-8 in nasal fibroblasts at mRNA and protein levels. DEP induced phosphorylation of p38, Akt, and NF-κB, whereas inhibitors of p38, Akt, and NF-κB blocked these phophorylations and the expressions of IL-6 and IL-8. These findings were also observed in ex vivo organ culture of nasal inferior turbinate.

Conclusions

DEP induces expression of IL-6 and IL-8 via p38, Akt, and NF-κB signaling pathways in nasal fibroblasts. This finding suggests that air pollution might induce or aggravate allergic rhinitis or chronic rhinosinusitis.

Toll-like receptor 4-mediated expression of interleukin-32 via the c-Jun N-terminal kinase/protein kinase B/cyclic adenosine monophosphate response element binding protein pathway in chronic rhinosinusitis with nasal polyps

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is prolonged inflammation of the sinonasal mucosa. Interleukin-32 (IL-32) is involved in the pathogenesis of chronic lung inflammatory diseases. The aim of study is to compare the expression level of IL-32 in normal nasal mucosa and CRSwNP and to investigate the mechanism underlying IL-32 expression in CRSwNP.

METHODS

IL-32 expression in nasal tissues, normal nasal mucosa-derived fibroblasts (NorDFs) and nasal polyp-derived fibroblasts (NPDFs), ex vivo explants of nasal tissues was measured by reverse-transcription polymerase chain reaction (RT-PCR), Western blotting, and enzyme-linked immunosorbent assay (ELISA). NorDFs and NPDFs were exposed to lipopolysaccharide (LPS) and the expression level of IL-32 was measured. LPS from Rhodobactersphaeroides (RS) and small interference RNA against Toll-like receptor 4 (siTLR4) were used to inhibit signaling by TLR4. Activation of mitogen-activated protein kinase (MAPKs) (extracellular related kinase [ERK], p38, and c-Jun N-terminal kinase [JNK]), protein kinase B (AKT), and cyclic adenosine monophosphate response element binding protein (CREB) was examined using western blot analysis.

RESULTS

Expression of IL-32 was increased in CRSwNP compared to normal nasal mucosa. LPS induced expression of IL-32 in a time-dependent manner. The induction of IL-32 expression in NPDFS was more effective than in NorDFs. Treatment with RS and siTLR4 inhibited the messenger RNA (mRNA) expression of TLR4, myeloid differentiation primary response 88 (MyD88), and IL-32 in LPS-stimulated NPDFs. IL-32 expression was specifically activated by JNK, AKT, and CREB in LPS-stimulated NPDFs and CRSwNP ex vivo explants.

CONCLUSION

The sensitivity for IL-32 expression by LPS was increased in CRSwNP compared to normal nasal mucosa. LPS effectively induced IL-32 expression in NPDFs than in NorDFs through the TLR4-JNK-AKT-CREB signaling pathway. Therefore, IL-32 seems to be involved in the pathogenesis of CRSwNP.

Onbaekwon Suppresses Colon Cancer Cell Invasion by Inhibiting Expression of the CXC Chemokine Receptor 4

Cysteine X cysteine (CXC) chemokine receptor 4 (CXCR4) and C-X-C motif chemokine 12 (CXCL12) were originally identified as chemoattractants between immune cells and sites of inflammation. Since studies have validated an increased level of CXCL12 and its receptor in patients with colorectal cancers, CXCL12/CXCR4 axis has been considered as a valuable marker of cancer metastasis. Therefore, identification of CXCR4 inhibitors has great potential to abrogate tumor metastasis. Onbaekwon (OBW) is a complex herbal formula that is derived from the literature of traditional Korean medicine Dongeuibogam. In this study, we demonstrated that OBW suppressed CXCR4 expression in various cancer cell types in a concentration- and time-dependent manner. Both proteasomal and lysosomal inhibitors had no effect to prevent the OBW-induced suppression of CXCR4, suggesting that the inhibitory effect of OBW was not due to proteolytic degradation but occurred at the transcriptional level. Electrophoretic mobility shift assay further confirmed that OBW could block endogenous activation of nuclear factor kappa B, a key transcription factor that regulates the expression of CXCR4 in colon cancer cells. Consistent with the aforementioned molecular basis, OBW abolished cell invasion induced by CXCL12 in colon cancer cells. Together, our results suggest that OBW, as a novel inhibitor of CXCR4, could be a promising therapeutic agent contributing to cancer treatment.

Arsenic Trioxide Attenuates NF-κB and Cytokine mRNA Levels in the Livers of Cocks

Arsenic (As) is a trace element widely found in nature. It exists in several forms, including organic arsenic, inorganic arsenic, and trivalent arsenic, the most toxic. Arsenic trioxide (As2O3) is widespread in nature. This form tends to accumulate in animals and humans and therefore has a potential harm for them. Cytokines play essential roles in the immune response and inflammation. Although the importance of cytokines in the responses to arsenic exposure has been demonstrated in many types of mammals, the function of these in poultry, especially in chickens, remains unclear. The purpose of the present study was to examine the effect of As2O3 exposure on cytokines in cock livers. In this study, 72 1-day-old male Hy-line cocks were randomly divided into four groups including the control group, low-As group, middle-As group, and high-As group. The livers were collected on days 30, 60, and 90 of the experiment. The levels of nuclear factor-kappa B (NF-κB), tumor necrosis factor-alpha (TNF-α), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-12 beta (IL-12β), and interleukin-1 beta (IL-1β) mRNA in the livers of the cocks were measured using real-time PCR. The results showed that the expression levels of IL-6, IL-8, TNF-α, and NF-κB which seemed to be a critical mediator in the inflammatory response tended to increase in the birds chronically treated with As2O3. However, the mRNA expression levels of IL-4, IL-12β, and IL-1β were decreased in the experiment. The information regarding the effects of As2O3 on cytokine mRNA expression generated in this study will be important information for arsenic toxicology evaluation.

Expression of MMP-9/TIMP-2 in nasal polyps and its functional implications

Nasal polyps (NP) involve tissue repair and structural remodel, both of which require the extracellular matrix. Matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) are known regulators for tissue reconstruction. This study therefore aimed to analyze the expressional profile of MMP-9 and TIMP-2 in NP patients, with further investigation of their roles in pathogenesis. A total of 60 NP tissue samples (including 15 type I, 21 type II and 24 type III) were collected from surgeries in our hospital, in addition to 6 normal ethmoid sinus mucosa samples. The mRNA and protein expression levels of MMP-9/TIMP-2 were quantified by real-time PCR and Western blotting, respectively. Serum levels were also checked by enzyme-linked immunosorbent assay (ELISA). Both mRNA and protein levels of MMP-9 in NP tissues or serum were significantly elevated compared to those in control ones (P<0.05) while the TIMP-2 expression was suppressed (P<0.05). In patients with more advanced stage, MMP-9 expression was further elevated, with lowered TIMP-2 levels (P<0.05 in both cases). Pathogenesis and progression of NP is closely related with elevated MMP-9 and suppressed TIMP-2 expression, suggesting the role of those factors as indexes for evaluating NP stage. Our results also provide evidences for further studies of pathogenesis and drug targets of NP.

Regulation of PGE2 signaling pathways and TNF-alpha signaling pathways on the function of bone marrow-derived dendritic cells and the effects of CP-25

This study was to investigate PGE2 and TNF-alpha signaling pathway involving in the maturation and activation of bone marrow dendritic cells (DCs) and the effect of CP-25. Bone marrow DCs were isolated and stimulated by PGE2 and TNF-alpha respectively. The markers of maturation and activation expressed on DCs, such as CD40, CD80, CD83, CD86, MHC-II, and the ability of antigen uptake of DCs were analyzed by flow cytometry. The proliferation of T cells co-cultured with DCs, the signaling pathways of PGE2-EP4-cAMP and TNF-alpha-TRADD-TRAF2-NF-κB in DCs were analyzed. The results showed that both PGE2 and TNF-alpha up-regulated the expressions of CD40, CD80, CD83, CD86, and MHC-II, decreased the antigen uptake of DCs, and DCs stimulated by PGE2 or TNF-alpha could increase T cell proliferation. CP-25 (10(-5), 10(-6), and 10(-7)mol/l) decreased significantly the expressions of CD40, CD80, CD83, CD86 and MHC-II, increased the antigen uptake of DCs, and suppressed T cell proliferation induced by DCs. PGE2 increased the expressions of EP4, NF-κB and down-regulated cAMP level of DCs. TNF-alpha could also up-regulate TNFR1, TRADD, TRAF2, and NF-κB expression of DCs. CP-25 (10(-5), 10(-6), and 10(-7)mol/l) decreased the expressions of EP4 and NF-κB, increased cAMP level in DCs stimulated by PGE2. CP-25 (10(-5), 10(-6), and 10(-7)mol/l) also could down-regulate significantly TNFR1, TRADD, TRAF2, and NF-κB expression in DCs stimulated by TNF-alpha. These results demonstrate that PGE2 and TNF-alpha could enhance DCs functions by mediating PGE2-EP4-cAMP pathway, TNF-alpha-TNFR1-TRADD-TRAF2-NF-κB pathway respectively. CP-25 might inhibit the function of DCs through regulating PGE2-EP4-cAMP and TNF-alpha-TNFR1-TRADD-TRAF2-NF-κB pathways.

NF-κB signaling pathway confers neuroblastoma cells migration and invasion ability via the regulation of CXCR4

Background

Accumulating evidence implicates the transcription factor NF-κB as a positive mediator of tumor metastasis, but the molecular mechanism(s) involved in this process remains largely unknown. In this study, we investigated the role of NF-κB signaling pathway in the regulation of CXC chemokine receptor-4 (CXCR4) in neuroblastoma metastasis.

Material/Methods

NF-κB, CXCR4 mRNA and protein expression were measured by RT-PCR, and Western blot. Tumor necrosis factor-a (TNF-α) was used to induce the upregulation of NF-κB and CXCR4. The knockdown of NF-κB and CXCR4 was achieved by PDTC. Transwell assay was used to investigate the role of NF-κB (P65) in neuroblastoma cell migration and invasion. An in vitro co-culture system was established to investigate the role of tumor microenvironment in regulation of the NF-κB signaling pathway.

Results

Over-expression of NF-κB (p65) promoted tumor migration and invasion through the upregulation of CXCR4; however, knockdown of NF-κB(P65) inhibited tumor migration and invasion through blocking the expression of CXCR4. Consistently, in the co-culture system, the expression of CXCR4 was partly dependent on the expression of NF-κB (p65).

Conclusions

Our studies reveal critical roles for the NF-κB signaling pathway in neuroblastoma migration and invasion. The mechanism may be through up-regulation of CXCR4, mediated by the NF-κB signaling pathways. Targeting NF-κB signalling pathways and ultimately CXCR4 could be a strategy in neuroblastoma therapy.