KinScan: AI-based rapid profiling of activity across the kinome.

Kinases play a vital role in regulating essential cellular processes, including cell cycle progression, growth, apoptosis, and metabolism, by catalyzing the transfer of phosphate groups from adenosing triphosphate to substrates. Their dysregulation has been closely associated with numerous diseases, including cancer development, making them attractive targets for drug discovery. However, accurately predicting the binding affinity between chemical compounds and kinase targets remains challenging due to the highly conserved structural similarities across the kinome. To address this limitation, we present KinScan, a novel computational approach that leverages large-scale bioactivity data and integrates the Multi-Scale Context Aware Transformer framework to construct a virtual profiling model encompassing 391 protein kinases. The developed model demonstrates exceptional prediction capability, distinguishing between kinases by utilizing structurally aligned kinase binding site features derived from multiple sequence alignment for fast and accurate predictions. Through extensive validation and benchmarking, KinScan demonstrated its robust predictive power and generalizability for large-scale kinome-wide profiling and selectivity, uncovering associations with specific diseases and providing valuable insights into kinase activity profiles of compounds. Furthermore, we deployed a web platform for end-to-end profiling and selectivity analysis, accessible at https://kinscan.drugonix.com/softwares/kinscan.

Therapeutic Applications of Extracellular Vesicles in Inflammatory Bowel Disease.

The treatment landscape for inflammatory bowel disease (IBD) has undergone substantial advancements with the introduction of biologics. However, a considerable number of patients either show an immediate lack of response or lose responsiveness over time, necessitating the development of innovative and effective treatment approaches. Extracellular vesicles (EVs) are small lipid bilayer-enclosed structures that facilitate cell-to-cell molecular transfer and are integral to the pathogenesis of IBD. They play pivotal roles in maintaining the integrity of the intestinal epithelial barrier and the expulsion of cellular metabolites. The potential use of EVs as drug carriers or therapeutic agents has opened up a plethora of clinical applications. This review investigates the creation and content of EVs, their role in IBD development, and advances in their isolation and analytical techniques. Furthermore, the therapeutic promise they hold for IBD is explored, along with the latest research on their roles as IBD drug delivery systems.

Role of Nasal Fibroblasts in Airway Remodeling of Chronic Rhinosinusitis: The Modulating Functions Reexamined.

Chronic rhinosinusitis (CRS) is a multifactorial inflammatory disease of the nose and sinuses that affects more than 10% of the adult population worldwide. Currently, CRS is classified into endotypes according to the inflammatory response (Th1, Th2, and Th17) or the distribution of immune cells in the mucosa (eosinophilic and non-eosinophilic). CRS induces mucosal tissue remodeling. Extracellular matrix (ECM) accumulation, fibrin deposition, edema, immune cell infiltration, and angiogenesis are observed in the stromal region. Conversely, epithelial-to-mesenchymal transition (EMT), goblet cell hyperplasia, and increased epithelial permeability, hyperplasia, and metaplasia are found in the epithelium. Fibroblasts synthesize collagen and ECM, which create a structural skeleton of tissue and play an important role in the wound-healing process. This review discusses recent knowledge regarding the modulation of tissue remodeling by nasal fibroblasts in CRS.

The EphA1 and EphA2 Signaling Modulates the Epithelial Permeability in Human Sinonasal Epithelial Cells and the Rhinovirus Infection Induces Epithelial Barrier Dysfunction via EphA2 Receptor Signaling.

Deficiencies in epithelial barrier integrity are involved in the pathogenesis of chronic rhinosinusitis (CRS). This study aimed to investigate the role of ephrinA1/ephA2 signaling on sinonasal epithelial permeability and rhinovirus-induced epithelial permeability. This role in the process of epithelial permeability was evaluated by stimulating ephA2 with ephrinA1 and inactivating ephA2 with ephA2 siRNA or inhibitor in cells exposed to rhinovirus infection. EphrinA1 treatment increased epithelial permeability, which was associated with decreased expression of ZO-1, ZO-2, and occludin. These effects of ephrinA1 were attenuated by blocking the action of ephA2 with ephA2 siRNA or inhibitor. Furthermore, rhinovirus infection upregulated the expression levels of ephrinA1 and ephA2, increasing epithelial permeability, which was suppressed in ephA2-deficient cells. These results suggest a novel role of ephrinA1/ephA2 signaling in epithelial barrier integrity in the sinonasal epithelium, suggesting their participation in rhinovirus-induced epithelial dysfunction.

Eosinophilic Chronic Rhinosinusitis and Pathogenic Role of Protease.

Chronic rhinosinusitis (CRS) is an inflammation of the nasal and paranasal sinus mucosa, and eosinophilic CRS (eCRS) is a subtype characterized by significant eosinophil infiltration and immune response by T-helper-2 cells. The pathogenesis of eCRS is heterogeneous and involves various environmental and host factors. Proteases from external sources, such as mites, fungi, and bacteria, have been implicated in inducing type 2 inflammatory reactions. The balance between these proteases and endogenous protease inhibitors (EPIs) is considered important, and their imbalance can potentially lead to type 2 inflammatory reactions, such as eCRS. In this review, we discuss various mechanisms by which exogenous proteases influence eCRS and highlight the emerging role of endogenous protease inhibitors in eCRS pathogenesis.

Anticancer Activity of Mannose-Specific Lectin, BPL2, from Marine Green Alga Bryopsis plumosa.

Lectin is a carbohydrate-binding protein that recognizes specific cells by binding to cell-surface polysaccharides. Tumor cells generally show various glycosylation patterns, making them distinguishable from non-cancerous cells. Consequently, lectin has been suggested as a good anticancer agent. Herein, the anticancer activity of Bryopsis plumosa lectins (BPL1, BPL2, and BPL3) was screened and tested against lung cancer cell lines (A549, H460, and H1299). BPL2 showed high anticancer activity compared to BPL1 and BPL3. Cell viability was dependent on BPL2 concentration and incubation time. The IC50 value for lung cancer cells was 50 µg/mL after 24 h of incubation in BPL2 containing medium; however, BPL2 (50 µg/mL) showed weak toxicity in non-cancerous cells (MRC5). BPL2 affected cancer cell growth while non-cancerous cells were less affected. Further, BPL2 (20 µg/mL) inhibited cancer cell invasion and migration (rates were ˂20%). BPL2 induced the downregulation of epithelial-to-mesenchymal transition-related genes (Zeb1, vimentin, and Twist). Co-treatment with BPL2 and gefitinib (10 µg/mL and 10 µM, respectively) showed a synergistic effect compared with monotherapy. BPL2 or gefitinib monotherapy resulted in approximately 90% and 70% cell viability, respectively, with concomitant treatment showing 40% cell viability. Overall, BPL2 can be considered a good candidate for development into an anticancer agent.

DNMTs Are Involved in TGF-ß1-Induced Epithelial-Mesenchymal Transitions in Airway Epithelial Cells.

Chronic rhinosinusitis (CRS) pathogenesis is closely related to tissue remodeling, including epithelial-mesenchymal transition (EMT). Epigenetic mechanisms play key roles in EMT. DNA methylation, mediated by DNA methyltransferases (DNMTs), is an epigenetic marker that is critical to EMT. The goal of this study was to determine whether DNMTs were involved in TGF-ß1-induced EMT and elucidate the underlying mechanisms in nasal epithelial cells and air-liquid interface cultures. Global DNA methylation and DNMT activity were quantified. DNMT expression was measured using real-time PCR (qRT-PCR) in human CRS tissues. mRNA and protein levels of DNMTs, E-cadherin, vimentin, α-SMA, and fibronectin were determined using RT-PCR and Western blotting, respectively. DNMT1, DNMT3A, and DNMT3B gene expression were knocked down using siRNA transfection. MAPK phosphorylation and EMT-related transcription factor levels were determined using Western blotting. Signaling pathways were analyzed using specific inhibitors of MAPK. We demonstrated these data in primary nasal epithelial cells and air-liquid interface cultures. Global DNA methylation, DNMT activity, and DNMT expression increased in CRS tissues. DNMT expression was positively correlated with Lund-McKay CT scores. TGF-ß1 dose-dependently induced DNMT expression. Further, 5-Aza inhibited TGF-ß1-induced DNMT, Snail, and Slug expression related to EMT, as well as p38 and JNK phosphorylation in A549 cells and TGF-ß1-induced DNMT expression and EMT in primary nasal epithelial cells and air-liquid interface cultures. TGF-ß1-induced DNMT expression leads to DNA methylation and EMT via p38, JNK, Snail, and Slug signaling pathways. Inhibition of DNMT suppressed the EMT process and therefore is potentially a CRS therapeutic strategy.

Association between metabolic syndrome and periodontitis: The role of lipids, inflammatory cytokines, altered host response, and the microbiome.

Periodontitis has been associated with many systemic diseases and conditions, including metabolic syndrome. Metabolic syndrome is a cluster of conditions that occur concomitantly and together they increase the risk of cardiovascular disease and double the risk of type 2 diabetes. In this review, we focus on the association between metabolic syndrome and periodontitis; however, we also include information on diabetes mellitus and cardiovascular disease, since these two conditions are significantly intertwined with metabolic syndrome. With regard to periodontitis and metabolic syndrome, to date, the vast majority of studies point to an association between these two conditions and also demonstrate that periodontitis can contribute to the development of, or can worsen, metabolic syndrome. Evaluating the effect of metabolic syndrome on the salivary microbiome, data presented herein support the hypothesis that the salivary bacterial profile is altered in metabolic syndrome patients compared with healthy patients. Considering periodontitis and these three conditions, the vast majority of human and animal studies point to an association between periodontitis and metabolic syndrome, diabetes, and cardiovascular disease. Moreover, there is evidence to suggest that metabolic syndrome and diabetes can alter the oral microbiome. However, more studies are needed to fully understand the influence these conditions have on each other.

Risk Model Establishment of Endoscopic Sinus Surgery for Patients with Chronic Rhinosinusitis: a Multicenter Study in Korea.

BACKGROUND: Endoscopic sinus surgery (ESS) is the mainstay treatment for refractory chronic rhinosinusitis (CRS). Since various factors may contribute to the surgical outcome, it is challenging for physicians to predict surgical outcomes. The aim of study was to analyze the prognostic factors of postoperative outcomes and to establish the prediction model with the risk factors that impact the postoperative outcomes. METHODS: Medical records of CRS patients who underwent ESS at 9 institutions in 2005, 2010, and 2016 were retrospectively reviewed. We classified the patients into 2 groups based on postoperative objective endoscopic outcomes. Demographics, nose-specific symptoms, olfactory function, eosinophil counts in blood (EoB) and nasal tissue (EoT), and Lund-Mackay CT score (LMS) were collected. Univariate and multivariate analyses were performed and established a prediction equation for postoperative endoscopic objective outcomes. RESULTS: In total (n = 1,249), 27.0% were not satisfied under postoperative endoscopic examination. Of 10 variables, LMS (> 5), sinus dominancy (maxillary sinus and ethmoid sinus), EoB (> 210), and EoT (> 100) were statistically significant in univariate analysis (P < 0.05, all). In multivariate analysis, EoT (> 100) and LMS (> 5) were significantly associated with poor postoperative outcome. Furthermore, 5 significant variables were employed to establish the risk model of postoperative outcomes and P (the value of prediction probability) = 1 / (1 + exp [-0.392 + 1.088 × EoT (> 100) + 0.123 × mean LMS (> 5) - 0.366 × sinus dominancy (maxillary) + 0.064 × sinus dominancy (similar) + 0.200 × EoB (4%) + 0.344 × EoB (> 210)] was developed. CONCLUSION: Tissue eosinophil count and radiographic severity predispose to a poorer outcome of ESS and the risk model established may be helpful to predict postoperative outcomes of ESS.

miR-29b Regulates TGF-ß1-Induced Epithelial-Mesenchymal Transition by Inhibiting Heat Shock Protein 47 Expression in Airway Epithelial Cells.

Tissue remodeling contributes to ongoing inflammation and refractoriness of chronic rhinosinusitis (CRS). During this process, epithelial-mesenchymal transition (EMT) plays an important role in dysregulated remodeling and both microRNA (miR)-29b and heat shock protein 47 (HSP47) may be engaged in the pathophysiology of CRS. This study aimed to determine the role of miR-29b and HSP47 in modulating transforming growth factor (TGF)-ß1-induced EMT and migration in airway epithelial cells. Expression levels of miR-29b, HSP47, E-cadherin, α-smooth muscle actin (α-SMA), vimentin and fibronectin were assessed through real-time PCR, Western blotting, and immunofluorescence staining. Small interfering RNA (siRNA) targeted against miR-29b and HSP47 were transfected to regulate the expression of EMT-related markers. Cell migration was evaluated with wound scratch and transwell migration assay. miR-29b mimic significantly inhibited the expression of HSP47 and TGF-ß1-induced EMT-related markers in A549 cells. However, the miR-29b inhibitor more greatly induced the expression of them. HSP47 knockout suppressed TGF-ß1-induced EMT marker levels. Functional studies indicated that TGF-ß1-induced EMT was regulated by miR-29b and HSP47 in A549 cells. These findings were further verified in primary nasal epithelial cells. miR-29b modulated TGF-ß1-induced EMT-related markers and migration via HSP47 expression modulation in A549 and primary nasal epithelial cells. These results suggested the importance of miR-29b and HSP47 in pathologic tissue remodeling progression in CRS.

Inflachromene inhibits autophagy through modulation of Beclin 1 activity.

Autophagy is a central intracellular catabolic mechanism that mediates the degradation of cytoplasmic proteins and organelles, and regulation of autophagy is essential for homeostasis. HMGB1 is an important sepsis mediator when secreted and also functions as an inducer of autophagy by binding to Beclin 1. In this study, we studied the effect of inflachromene (ICM), a novel HMGB1 secretion inhibitor, on autophagy. ICM inhibited autophagy by inhibiting nucleocytoplasmic translocation of HMGB1 and by increasing Beclin 1 ubiquitylation for degradation by enhancing the interaction between Beclin 1 and E3 ubiquitin ligase RNF216. These data suggest that ICM could be used as a potential autophagy suppressor.

MR Findings of Fungus Ball: Significance of High Signal Intensity on T1-Weighted Images.

BACKGROUND: Central dark-signal intensity with high-signal, hypertrophic mucosal wall of paranasal sinuses on T2-weighted images (T2WI) is a characteristic magnetic resonance imaging (MRI) feature of sinonasal fungus ball. However, this finding is usually interpreted as non-fungal chronic sinusitis with central normal sinus air. In addition, T1-weighted images (T1WI) and T2WI are basic sequences of all magnetic resonance (MR) examinations. Therefore, we evaluated the usefulness of T1WI for detecting fungus balls comparing with computed tomography (CT) findings and T2-weighted MRI findings. METHODS: This retrospective study was approved by the Institutional Review Board of Korea University Guro Hospital. Two reviewers assessed preoperative CT and MR images of 55 patients with pathologically confirmed fungus balls. Reviewers evaluated the presence and patterns of calcifications on CT. Overall signals and the presence and extent of certain signals of fungus balls on MRI were also assessed. The relationship between calcifications and MRI signals was also evaluated. RESULTS: Of the patients, 89.1% had calcifications on CT. All had dark signal portions with high signal, hypertrophic mucosal walls on T2WI. Most (92.7%) patients showed iso- to hyper-intense overall signals on T1WI and 89.1% had T1-weighted high signal portions on MRI. The presence, patterns, and location of calcifications had no significant correlation with T1-weighted high-signal intensity portion. CONCLUSION: Fungus ball can be suggested by the presence of the hyper-signal intensity portions in the fungal mass on T1WI in conjunction with dark-signal lesions surrounded by high-signal, hypertrophic mucosal walls in paranasal sinuses on T2WI.

Clinicopathologic characteristics of paranasal sinus fungus ball: retrospective, multicenter study in Korea.

PURPOSE: Fungus ball (FB) is the most common type of fungal rhinosinusitis and the prevalence of FB has increased over the past 10 years. The aim of this study was to compare the clinical characteristics of Korean adult patients with FB and chronic rhinosinusitis (CRS) without FB. METHODS: We retrospectively analyzed data on 1362 patients (147 FB and 1215 CRS) who underwent endoscopic sinus surgery at nine Korean medical centers in 2005, 2010, and 2016. We evaluated the prevalence of FB and compared the clinical characteristics of FB and CRS. Medical records, computed tomography (CT) findings, atopic status, concomitant diseases, tissue, and blood eosinophil count were assessed. RESULTS: The prevalence of FB was significantly higher in 2016 (15.9%) than in the other years (7.8% in 2005 and 7.5% in 2010). The FB patients were more likely to be female, older, have unilateral disease and less likely to have allergy compared to the CRS patients. The most common main complaint related to CRS and FB was nasal obstruction. CT determined that unilateral disease and maxillary sinus dominancy were common in patients with FB. The incidence of concomitant diseases was much higher in FB, with lower tissue and blood eosinophilia. CONCLUSION: FB is commonly encountered in older women with the increased prevalence. FB had a different clinical presentation, radiological findings, and prognosis than CRS. Further studies are needed to understand the pathophysiologic mechanisms underlying the development of FB.

Position Tracking Techniques Using Multiple Receivers for Anti-Drone Systems.

The need for drone traffic control management has emerged as the demand for drones increased. Particularly, in order to control unauthorized drones, the systems to detect and track drones have to be developed. In this paper, we propose the drone position tracking system using multiple Bluetooth low energy (BLE) receivers. The proposed system first estimates the target's location, which consists of the distance and angle, while using the received signal strength indication (RSSI) signals at four BLE receivers and gradually tracks the target based on the estimated distance and angle. We propose two tracking algorithms, depending on the estimation method and also apply the memory process, improving the tracking performance by using stored previous movement information. We evaluate the proposed system's performance in terms of the average number of movements that are required to track and the tracking success rate.

Glucocorticoids ameliorate periostin-induced tissue remodeling in chronic rhinosinusitis with nasal polyps.

BACKGROUND: Periostin plays an important role in the development of chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP). Glucocorticoids (GCs) are anti-inflammatory drugs used to treat CRS, but the mechanism for inhibiting periostin-induced tissue remodeling is still unclear. We sought to investigate the expression of periostin, α-SMA, and extracellular matrix (ECM) components in sinonasal tissues and to evaluate the inhibitory mechanism of GCs in nasal fibroblasts and mucosa. METHODS: We measured the expression of periostin, α-SMA and ECM components in sinonasal tissues. Correlation of CRS severity and periostin was evaluated by the Lund-Mackey score. Fibroblasts and ex vivo culture of the inferior turbinate were used to investigate the effects of GCs on periostin-induced alterations using real-time PCR, western blot, and immunostaining. Wound healing, transwell invasion, and collagen gel contraction were performed to evaluate migration and collagen contraction. RESULTS: Periostin was highly expressed in eosinophilic CRSwNP and correlated with the Lund-Mackay score. In nasal fibroblasts, periostin increased tissue remodeling involved protein. GCs suppressed the alterations of periostin. In addition, periostin induced activation of Src/AKT/mTOR, which was inhibited by GCs. GCs also inhibited periostin-induced migration, invasion, and collagen gel contraction. CONCLUSION: We suggest that GCs are therapeutic agents for CRSwNP by inhibiting tissue remodeling through their inhibitory effect on Src/Akt/mTOR signaling pathway. This article is protected by copyright. All rights reserved.

Bony Changes in a Unilateral Maxillary Sinus Fungal Ball.

OBJECTIVES: In the paranasal sinus fungal ball (SFB), changes that occur in the underlying bone have not been well described. Recently, bacterial coinfection has been reported in patients with paranasal SFB. We evaluated whether bone changes occur in patients with unilateral maxillary SFB, and also how bacteria in an SFB affect the bony wall of the sinus. METHODS: A retrospective study of patients with a unilateral maxillary SFB undergoing endoscopic sinus surgery was conducted from July 2009 to December 2015. Preoperative computed tomography images of the patients were reviewed. Wall thickness (WT) and wall density (WD) of the diseased sinus were measured and compared to the normal sinus. Specimens of the sinus aspirates were obtained during surgery for aerobic and anaerobic cultures. RESULTS: Forty-three patients were included (mean, 55.7 ±â€Š12.8 years). Thirty-one cultures (72.1%) were positive for bacteria. Thickening was evident in the anterior, lateral, and posterior walls of the diseased sinus. The average WT was 1.69 ±â€Š0.45 mm on the diseased sinus and 1.14 ±â€Š0.31 mm on the normal sinus (P < 0.001). In the diseased sinus, the difference in the average WT between the culture-positive and culture-negative groups was not significant (P = 0.44). The average WD on the diseased sinus was higher than that on the normal sinus (P < 0.001). CONCLUSIONS: Osteitic change occurred in most patients with a unilateral maxillary SFB. The presence of bacteria in sinus secretions does not greatly affect the development of osteitic changes in unilateral maxillary SFB.

A Case of Cutaneous Myiasis Caused by Cordylobia anthropophaga Larvae in a Korean Traveler Returning from Central Africa.

The cutaneous myiasis has been rarely reported in the Republic of Korea. We intended to describe here a case of furuncular cutaneous myiasis caused by Cordylobia anthropophaga larvae in a Korean traveler returned from Central Africa. A patient, 55-year-old man, had traveled to Equatorial Guinea, in Central Africa for a month and just returned to Korea. Physical examinations showed 2 tender erythematous nodules with small central ulceration on the left buttock and thigh. During skin biopsy, 2 larvae came out from the lesion. C. anthropophaga was identified by paired mouth hooks (toothed, spade-like, oral hooklets) and 2 posterior spiracles, which lack a distinct chitinous rim. Although rarely described in Korea until now, cutaneous myiasis may be encountered more frequently with increasing international travel and exchange workers to tropical areas.

Chemical Chaperone of Endoplasmic Reticulum Stress Inhibits Epithelial-Mesenchymal Transition Induced by TGF-ß1 in Airway Epithelium via the c-Src Pathway.

Epithelial-mesenchymal transition (EMT) is a biological process that allows epithelial cells to assume a mesenchymal cell phenotype. EMT is considered as a therapeutic target for several persistent inflammatory airway diseases related to tissue remodeling. Herein, we investigated the role of endoplasmic reticulum (ER) stress and c-Src in TGF-ß1-induced EMT. A549 cells, primary nasal epithelial cells (PNECs), and inferior nasal turbinate organ cultures were exposed to 4-phenylbutylic acid (4PBA) or PP2 and then stimulated with TGF-ß1. We found that E-cadherin, vimentin, fibronectin, and α-SMA expression was increased in nasal polyps compared to inferior turbinates. TGF-ß1 increased the expression of EMT markers such as E-cadherin, fibronectin, vimentin, and α-SMA and ER stress markers (XBP-1s and GRP78), an effect that was blocked by PBA or PP2 treatment. 4-PBA and PP2 also blocked the effect of TGF-ß1 on migration of A549 cells and suppressed TGF-ß1-induced expression of EMT markers in PNECs and organ cultures of inferior turbinate. In conclusion, we demonstrated that 4PBA inhibits TGF-ß1-induced EMT via the c-Src pathway in A549 cells, PNECs, and inferior turbinate organ cultures. These results suggest an important role for ER stress and a diverse role for TGF-ß1 in upper airway chronic inflammatory disease such as CRS.

Efficacy of hyaluronic acid and hydroxyethyl starch in preventing adhesion following endoscopic sinus surgery.

Adhesion is a major complication of endoscopic sinus surgery that may lead to recurrence of chronic rhinosinusitis, necessitating revision surgery. The purpose of this study was to evaluate the effect of hyaluronic acid and hydroxyethyl starch (HA-HES) relative to hyaluronic acid and carboxymethylcellulose (HA-CMC) with regard to anti-adhesion effect. In this multi-center, prospective, single-blind, randomized controlled study, 77 consecutive patients who underwent bilateral endoscopic sinus surgery were enrolled between March 2014 and March 2015. HA-HES and HA-CMC were applied to randomly assigned ethmoidectomized cavities after the removal of middle meatal packing. At the 1st, 2nd and 4th weeks after surgery, the presence and grades of adhesion, edema, and infection were, respectively, examined via endoscopy by a blinded assessor. The incidence and grades of adhesion at the 2-week follow-up were significantly less in the HA-CMC group than in the HA-HES group (p < 0.05). However, with the exception of week 2, there were no significant differences in the incidence or grades of adhesion, edema, and infection between the two groups. When the primary endpoint-the presence of adhesion at the 4-week follow-up-was compared between two groups, the incidence of adhesion in HA-HES group at the 4-week follow-up was 32% and in HA-CMC was 41.3%, indicating that HA-HES was not inferior to HA-CMC in terms of anti-adhesive effect. No severe adverse reactions were noted during the study period. In conclusion, HA-HES is a safe substitutional anti-adhesion agent that has equivalent effect as HA-CMC after endoscopic sinus surgery.

Diesel Exhaust Particles Enhance MUC4 Expression in NCI-H292 Cells and Nasal Epithelial Cells via the p38/CREB Pathway.

BACKGROUND: Diesel exhaust particles (DEPs), the major contributors to air pollution, induce inflammatory responses in the nasal epithelium. Overproduction of airway mucins is an important pathogenic finding in inflammatory airway diseases. OBJECTIVE: The aims of the present study were to determine the effect of DEPs on the expression of the mucin gene MUC4 and to investigate the underlying mechanism of DEP-induced MUC4 expression in NCI-H292 cells and primary nasal epithelial cells (PNECs). METHODS: NCI-H292 cells were stimulated for 24 h with DEPs. Messenger RNA (mRNA) and protein expression of MUC4 was determined by real-time reverse transcription (RT) polymerase chain reaction (PCR) and Western blotting. NCI-H292 cells were exposed to 3 mitogen-activated protein kinase inhibitors (U0126, SB203580, and SP600125) and a CREB (cAMP response element-binding protein) inhibitor prior to stimulation with DEPs, and MUC4 expression was examined by RT-PCR and Western blotting. PNECs were pretreated with a p38 inhibitor and CREB inhibitor prior to stimulation with DEPs, and MUC4 expression was then determined by RT-PCR and/or Western blotting. RESULTS: DEPs significantly increased the expression of MUC4 mRNA and protein. MUC4 mRNA and protein expression was inhibited by pretreatment with p38 and CREB inhibitors in NCI-H292 stimulated with DEPs. p38 and CREB inhibitors also blocked the expression of MUC4 mRNA and protein in DEP-stimulated PNECs. CONCLUSIONS: We demonstrated that DEPs stimulated the expression of MUC4 via the p38/CREB pathway in NCI-H292 cells and PNECs. The results of the present study pave the way for further studies on the role of MUC4 in DEP-induced hypersecretion in airway epithelium.