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Objectives@#. Obesity, which induces chronic low-grade systemic inflammation in the human body, is a known risk factor for various diseases. Recent studies have shown associations between various otorhinolaryngological diseases and obesity. In particular, inflammatory sinonasal diseases have been found to be strongly associated with obesity-related proinflammatory mediators. Many studies have been conducted to identify therapeutic agents for controlling obesity-related inflammatory airway diseases. Ghrelin, an endogenous peptide from the stomach, has anti-inflammatory and antioxidative effects in a wide range of tissues. However, the effect of ghrelin on the regulation of mucus secretion has not yet been studied in the human nasal mucosa. Therefore, we investigated the effects of ghrelin on lipopolysaccharide (LPS)/leptin-mediated MUC5AC expression and mechanisms involved in human nasal epithelial cells (HNEpCs). @*Methods@#. In HNEpCs, the effect and signaling pathways of ghrelin on LPS/leptin-induced MUC5AC expression were examined using reverse transcription polymerase chain reaction, real-time polymerase chain reaction, enzyme immunoassays, Western blotting, and immunofluorescence staining. @*Results@#. Growth hormone secretagogue receptor 1a (GHSR1a) was expressed in the HNEpCs. Ghrelin downregulated LPS/leptin-induced MUC5AC expression, which was abolished by D-Lys-3-growth hormone-releasing peptide 6 (D-Lys-3-GHRP-6). Ghrelin significantly inhibited LPS/leptin-activated extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinases (MAPKs). These ghrelin-mediated changes in MAPK activation were abolished by D-Lys-3-GHRP-6. These results showed that ghrelin inhibits LPS/leptin-induced MUC5AC overexpression by modulating the ERK1/2 and p38 MAPK pathways in HNEpCs. @*Conclusion@#. These findings suggest that ghrelin is a potential therapeutic agent for treating obesity-related inflammatory sinonasal diseases.
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Purpose@#Diffuse large B-cell lymphoma (DLBCL) is the most common hematologic malignancy worldwide. Although substantial improvement has been achieved by the frontline rituximab-based chemoimmunotherapy, up to 40%-50% of patients will eventually have relapsed or refractory disease, whose prognosis is extremely dismal. @*Materials and Methods@#We have carried out two prospective cohort studies that include over 1,500 DLBCL patients treated with rituximab plus CHOP (#NCT01202448 and #NCT02474550). In the current report, we describe the outcomes of refractory DLBCL patients. Patients were defined to have refractory DLBCL if they met one of the followings, not achieving at least partial response after 4 or more cycles of R-CHOP; not achieving at least partial response after 2 or more cycles of salvage therapy; progressive disease within 12 months after autologous stem cell transplantation. @*Results@#Among 1,581 patients, a total of 260 patients met the criteria for the refractory disease after a median time to progression of 9.1 months. The objective response rate of salvage treatment was 26.4%, and the complete response rate was 9.6%. The median overall survival (OS) was 7.5 months (95% confidence interval, 6.4 to 8.6), and the 2-year survival rate was 22.1%±2.8%. The median OS for each refractory category was not significantly different (p=0.529). @*Conclusion@#In line with the previous studies, the outcomes of refractory DLBCL patients were extremely poor, which necessitates novel approaches for this population.
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Empty nose syndrome is a rare complication caused by excessive removal of normal tissues after nose surgery. The main symptoms of empty nose syndrome are paradoxical nasal obstruction, dryness, crust and dyspnea. Medical treatments such as irrigation, humidification, and ointment are not very effective, so surgical treatments to reconstruct the normal nasal cavity using implant materials are often considered. If the implant is not properly inserted, the symptoms persist and the implant must be removed again, resulting in the only donor site complications. Therefore, it is essential to treat the implant well and insert it precisely. Here we describe a surgical procedure to manage implant materials using autologous costal cartilage in the form of block, diced, and crushed cartilage for augmentation technique.
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Purpose@#Dominant optic atrophy is one of the most common hereditary optic neuropathies, causing progressive bilateral vision loss that begins early in life. Optic atrophy 1 (OPA1) gene mutation brings about mitochondrial dysfunction, which results in clinical manifestations of dominant optic atrophy. Here, we report a case of dominant optic atrophy caused by the c.1334G>A mutation of the OPA1 gene, the first known case in Korea to our knowledge.Case summary: A 12-year-old female patient with no specific medical history or systemic symptoms visited our clinic complaining of a progressive decrease in vision in either eye. Slit-lamp microscopy, intraocular pressure, ocular motility, and pupil reflex were normal. However, her best-corrected visual acuity in both eyes was 20/100, and her color vision was reduced to 8/12 in Ishihara’s test. Fundus examination showed temporal pallor of the optic nerve head in both eyes, and a corresponding cecocentral scotoma was observed on Goldmann visual field examination. Optical coherence tomography revealed significant thinning of the peripapillary retinal fiber layer and macular ganglion cell layer in both eyes. Genetic examination confirmed the c.1334G>A mutation of the OPA1 gene. @*Conclusions@#We report a case of dominant optic nerve atrophy caused by c.1334G>A mutation of the OPA1 gene and its clinical manifestations.
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Background and Objectives@#Peroxiredoxin (Prx) is an antioxidant enzyme involved in signaling pathway. Prx2 is the most abundant in mammalian gray matter neurons and has protective role under oxidative stress. MUC5AC and MUC5B are typical mucin genes in human airway epithelial cells. Even if free radicals play a key role in chronic respiratory inflammatory diseases, the effects of the Prx2 on mucin expression and oxidative stress are not clearly known. The purpose of this study is to investigate the effect of Prx2 on lipopolysaccharide (LPS)-induced MUC5AC/5B expression and reactive oxygen species (ROS) in human airway epithelial cells.Subjects and Method In NCI-H292 cells and human nasal epithelial cells, the effects of Prx2 on LPS-induced MUC5AC/5B expression and ROS production were investigated using reverse transcriptase-polymerase chain reaction, real-time polymerase chain reaction, enzyme linked immunosorbent assay (ELISA) and flow cytometry analysis. @*Results@#MUC5AC, MUC5B mRNA expression and protein production were increased by LPS. ROS production was also increased by LPS. Prx2 suppressed the LPS-induced MUC5AC mRNA expression and protein production as well as ROS production. However, Prx2 did not inhibit MUC5B mRNA expression and protein production. N-acetylcysteine, diphenyleneiodonium, and apocynin also inhibited LPS-induced ROS production. @*Conclusion@#These results may show that Prx2 suppresses LPS-induced MUC5AC expression via ROS in human airway epithelial cells.
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Background and Objectives@#Ginsenoside Rb1 is the main metabolite of Panax ginseng. It is known to have many beneficial properties including anti-inflammatory, antitumoral and antioxidant effects. However, the therapeutic effects of ginenoside Rb1 on inflammatory airway diseases have not been elucidated. Therefore, we investigated the effects of ginsenoside Rb1 on the TGF-β1-induced mucin gene expression and epithelial-mesenchymal transition (EMT) in human airway epithelial cells.Materials and Method We evaluated the effects of ginsenoside Rb1 on the changes of MUC4, MUC5AC, occludin, claudin 4, claudin 18, neural (N)-cadherin, and epithelial (E)-cadherin expression by TGF-β1 in NCI-H292 cells using reverse, real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and western blot. @*Results@#TGF-β1 significantly increased MUC4/5AC expression. Rb1 inhibited TGF-β1- induced MUC4/5AC expression. In addition, TGF-β1 significantly attenuated occludin, claudin 18, and E-cadherin expressions but induced claudin 4 and N-cadherin expressions. On the other hand, Rb1 reversed changes in the TGF-β1- mediated expressions of cell junction molecules. @*Conclusion@#These results suggest that ginsenoside Rb1 attenuates TGF-β1-induced MUC4/5AC expressions and EMT in the human airway epithelial cells. These findings are important data demonstrating the potential of ginsenoside Rb1 as a therapeutic agent for inflammatory airway diseases.
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Histamine acts by binding to four histamine receptors (H1 to H4), of which the H1 is known to participate in dilate blood vessels, bronchoconstriction, and pruritus. Olopatadine hydrochloride blocks the release of histamine from mast cells and it inhibits H1 receptor activation. Olopatadine hydrochloride is anti-allergic agent that is effectively used. The object of this study had conducted to compare the pharmacokinetics (PKs) and safety characteristics between olopatadine hydrochloride 5 mg (test formulation) and olopatadine hydrochloride 5 mg (reference formulation; Alerac® ) in Korean subjects. This study had conducted an open-label, randomized, fasting condition, single-dose, 2-treatment, 2-period, 2-way crossover. Subjects received single-dosing of reference formulation or test formulation in each period and blood samples were collected over 24 hours after administration for PK analysis. A wash-out period of 7 days was placed between the doses. Plasma concentration of olopatadine were determined using liquid chromatography-tandem spectrometry mass (LC-MS/MS). A total of 32 subjects were enrolled and 28 subjects completed. There were not clinical significantly different in the safety between two treatment groups for 32 subjects who administered the study drug more than once. The geometric mean ratio of test formulation to reference formulation and its 90% confidence intervals for The peak plasma concentration (Cmax ) and the areas under the plasma concentration–time curve from 0 to the last concentration (AUClast ) were 1.0845 (1.0107–1.1637) and 1.0220 (1.0005–1.0439), respectively. Therefore, the test formulation was bioequivalent in PK characteristics and was equally safe as the reference formulation.
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Type 2 diabetes mellitus becomes increasingly more common with age. As such, older adults represent a very heterogeneous group in terms of functional ability and cognitive status. Older adults with diabetes are distinct from younger adults with diabetes, leading to differences in therapeutic approach. Some important goals of nutrition therapy in older adults with diabetes include minimizing hypoglycemia and hyperglycemia and meeting individualized glycemic goals. Nutrition therapy for older adults with diabetes should include meeting the nutritional needs for patients while considering their age, evaluating their fluid intake, avoiding significant weight loss, and being sensitive to individual preferences and long standing food habits while advocating good nutrition. However, there is little evidence for nutritional guidelines for older adults with diabetes, thus more research is needed.
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Objectives@#. The emergence of electronic cigarettes (e-cigarettes) has created new perceptions of the tobacco market. Unlike traditional tobacco, the greatest advantage of e-cigarettes is that they have less smell and are convenient and inexpensive. Most e-cigarette smokers believe that e-cigarette smoking is less harmful than traditional smoking. Information on the effects of e-cigarettes on human health is limited, and the issue remains controversial. @*Methods@#. We studied the effects of e-cigarette vapor on mucin (MUC5AC and MUC5B) and the change of MUC5AC and MUC5B from e-cigarette liquid with or without nicotine in respiratory epithelial cells. The effects of e-cigarette vapor with or without nicotine on mucin, along with the involved signaling pathways, were investigated using reverse transcriptase-polymerase chain reaction (PCR), real-time PCR, enzyme immunoassays, and immunoblot analysis with several specific inhibitors and small interfering RNA. @*Results@#. E-cigarette vapor with or without nicotine stimulated MUC5AC, but not MUC5B, expression in respiratory epithelial cells. In addition, we showed that e-cigarette vapor with and without nicotine induced MUC5AC expression via activation of the mitogen-activated protein kinase (MAPK; extracellular signal-regulated kinase [ERK] 1/2 and p38) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathways in human airway epithelial cells. @*Conclusion@#. E-cigarette vapor with and with nicotine significantly increased MUC5AC expression in human airway epithelial cells.
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The goal of cancer immunotherapy is to restore and optimize the immune response against malignant clones through several stages, from recognition of tumor antigens to establishment of long-lived memory cell populations. Boosting the intrinsic anti-tumor immune responses of the patients’ own, several types of “active immunotherapies” have been tried in many types of malignancies, inspired by successful experiences of immune checkpoint inhibition even in Hodgkin lymphoma. However, in B-cell non-Hodgkin lymphomas, clinical usefulness of such “active immunotherapies” is relatively unsatisfactory considering the remarkable advances in “passive immunotherapy,” including CD19-targeting chimeric antigen receptor T-cell therapy. Understanding how tumor cells and immune cells interact and contribute to immune evasion processes in the tumor microenvironment (TME) is an important prerequisite for the successful restoration of anti-tumor immune responses. In this review, a recent understanding of the biology of the immune tumor microenvironment surrounding B-cell non-Hodgkin lymphomas will be introduced. In addition, novel therapeutic approaches targeting the immune microenvironment other than immune checkpoint blockade are discussed.
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Objectives@#. The emergence of electronic cigarettes (e-cigarettes) has created new perceptions of the tobacco market. Unlike traditional tobacco, the greatest advantage of e-cigarettes is that they have less smell and are convenient and inexpensive. Most e-cigarette smokers believe that e-cigarette smoking is less harmful than traditional smoking. Information on the effects of e-cigarettes on human health is limited, and the issue remains controversial. @*Methods@#. We studied the effects of e-cigarette vapor on mucin (MUC5AC and MUC5B) and the change of MUC5AC and MUC5B from e-cigarette liquid with or without nicotine in respiratory epithelial cells. The effects of e-cigarette vapor with or without nicotine on mucin, along with the involved signaling pathways, were investigated using reverse transcriptase-polymerase chain reaction (PCR), real-time PCR, enzyme immunoassays, and immunoblot analysis with several specific inhibitors and small interfering RNA. @*Results@#. E-cigarette vapor with or without nicotine stimulated MUC5AC, but not MUC5B, expression in respiratory epithelial cells. In addition, we showed that e-cigarette vapor with and without nicotine induced MUC5AC expression via activation of the mitogen-activated protein kinase (MAPK; extracellular signal-regulated kinase [ERK] 1/2 and p38) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathways in human airway epithelial cells. @*Conclusion@#. E-cigarette vapor with and with nicotine significantly increased MUC5AC expression in human airway epithelial cells.
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The goal of cancer immunotherapy is to restore and optimize the immune response against malignant clones through several stages, from recognition of tumor antigens to establishment of long-lived memory cell populations. Boosting the intrinsic anti-tumor immune responses of the patients’ own, several types of “active immunotherapies” have been tried in many types of malignancies, inspired by successful experiences of immune checkpoint inhibition even in Hodgkin lymphoma. However, in B-cell non-Hodgkin lymphomas, clinical usefulness of such “active immunotherapies” is relatively unsatisfactory considering the remarkable advances in “passive immunotherapy,” including CD19-targeting chimeric antigen receptor T-cell therapy. Understanding how tumor cells and immune cells interact and contribute to immune evasion processes in the tumor microenvironment (TME) is an important prerequisite for the successful restoration of anti-tumor immune responses. In this review, a recent understanding of the biology of the immune tumor microenvironment surrounding B-cell non-Hodgkin lymphomas will be introduced. In addition, novel therapeutic approaches targeting the immune microenvironment other than immune checkpoint blockade are discussed.
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Bazedoxifene, used as bazedoxifene acetate, is a selective estrogen receptor modulator that selectively affects the uterus, breast tissue, bone metabolism, and lipid metabolism by antagonizing or enhancing estrogens in the estrogen receptor in the tissue. This study was conducted as an open, randomized, two-period, two-treatment, crossover design to compare the pharmacokinetic (PK) characteristics and tolerability of two bazedoxifene tablets when administered to 50 healthy Korean male volunteers. Enrolled subjects were randomly allocated to 2 sequences of a single oral administration of a test drug and a reference drug, or vice versa with a 14-day washout period between the two doses. Serial blood samples were collected over 96 h for PK analysis. Plasma concentration of bazedoxifene was assayed using liquid chromatography-tandem spectrometry mass. Forty-five participants completed the study with no clinically relevant safety issues. The peak concentrations (Cmax, mean ± strandard deviation) of reference drug and test drug were 3.191 ± 1.080 and 3.231 ± 1.346 ng/mL, respectively, and the areas under the plasma concentration‐time curve from 0 to the last measurable concentration (AUClast) were 44.697 ± 21.168 ng∙h/mL and 45.902 ± 23.130 ng∙h/mL, respectively. The geometric mean ratios of test drug to reference drug and their 90% confidence intervals for Cmax and AUClast were 0.9913 (0.8828–1.1132) and 1.0106 (0.9345–1.0929), respectively. The incidence of adverse events between the two formulations was similar. The present study showed that PK and tolerability of two bazedoxifene tablet formulations were comparable when administered to healthy Korean male volunteers.
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Background and Objectives@#Nicotine is oxidized into tobacco-specific nitrosamines (TSNAs; NAB, NAT, NNN, NNAL, NNK) at high temperature and high pressure. TSNAs are associated with airway diseases characterized by mucus hypersecretion as a major pathophysiologic phenomenon. The aim of study is to investigate the effect of TSNAs on mucin overexpression and its molecular mechanism in human airway epithelial cells.Materials and Method: The cytotoxicity of TSNAs was evaluated using EX-Cytox and inverted microscopy. The mRNA and protein levels of MUC5AC and MUC5B were measured using real-time PCR and ELISA. @*Results@#NAB, NNN, NNAL, and NNK did not affect cell viability. NAT did not affect cell viability up to a concentration of 100 μM in human airway epithelial cells. NAT, NNN, NNAL, and NNK significantly induced MUC5AC expression, but not MUC5B expression. NAB did not affect the expression of MUC5AC and MUC5B. Propranolol (a β-adrenergic receptor antagonist) inhibited NAT, NNN, NNAL, and NNK-induced MUC5AC expression, whereas α-bungarotoxin (an α7-nicotinic acetylcholine receptor antagonist) only inhibited NNN- and NNK-induced MUC5AC expression. @*Conclusion@#These results suggested that NAT, NNN, NNAL, and NNK induce MUC5AC expression through β-adrenergic receptor and/or α7-nicotinic acetylcholine receptor in human airway epithelial cells, which may be involved in mucus hypersecretion in inflammatory airway diseases.
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Background@#The prevalence of pulmonary hypertension (PH) in myeloproliferative neoplasms (MPNs) varies among studies. We analyzed the prevalence of PH in Korean patients with Philadelphia-negative (Ph-) MPNs. @*Methods@#Medical records of patients with Ph- MPNs [essential thrombocythemia (ET), polycythemia vera (PV), or primary myelofibrosis (PMF)] visiting a single hospital between 1993 and 2019 were reviewed retrospectively. Transthoracic echocardiographic examination (TTE) results were reviewed and PH was diagnosed according to established guidelines. @*Results@#Of the 320 MPN (179 ET, 107 PV, and 34 PMF) patients, 225 (121 ET, 83 PV, and 21 PMF) underwent TTE. Of these 225 MPN patients, 19 of 121 (15.7%) ET, 9 of 83 (10.8%) PV, and 6 of 21 (28.6%) PMF patients had PH. PV patients with PH were older [71 (42‒85) vs. 61.5 (26‒91) yr, respectively; P =0.049], predominantly female (male:female ratio, 0.29 vs. 1.96, respectively; P =0.010), had lower hemoglobin levels (15.9±2.6 g/dL vs. 18.4±2.6 g/dL, respectively; P =0.010), and higher platelet counts (616.6±284.2×109/L vs. 437.7±191.7×109/L, respectively; P =0.020) than PV patients without PH. PMF patients with PH had higher monocyte counts (1.3±0.5×109/L vs. 0.8±0.4×109/L, respectively; P =0.031) than those without PH. PH was a risk factor for poor survival in PV (HR, 12.4; 95% CI, 1.8‒86.6). @*Conclusion@#PH is common in patients with Ph- MPNs and hence, careful screening for PH is warranted.
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Primary central nervous system lymphoma (PCNSL) is a rare subtype of extranodal lymphoma primarily involving the brain, spinal cord, or leptomeninges. PCNSL is associated with a relatively poor prognosis compared to other extranodal diffuse large B-cell lymphomas. However, methotrexate-based induction chemotherapy followed by consolidative chemotherapy or high-dose therapy and autologous stem cell transplantation has improved the survival outcome, together with reduced neurotoxicity. Recent studies found that aberrant activation of the B-cell receptor-signaling pathway and activation of the NF-B are frequent genetic alterations and could be good targets for the treatment of PCNSL. Herein, we have reviewed the current status and recent advances in the biology and management of PCNSL.
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No abstract available.
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Humans , Anemia, Pernicious , Helicobacter pylori , HelicobacterABSTRACT
Korean Society of Thyroid-Head and Neck Surgery appointed a Task Force to provide guidance on the implementation of a surgical treatment of oral cancer. MEDLINE databases were searched for articles on subjects related to “surgical management of oral cancer” published in English. Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. The quality of evidence was rated with use RoBANS (Risk of Bias Assessment Tool for Nonrandomized Studies) and AMSTAR (A Measurement Tool to Assess the Methodological Quality of Systematic Reviews). Evidence-based recommendations for practice were ranked according to the American College of Physicians grading system. Additional directives are provided as expert opinions and Delphi questionnaire when insufficient evidence existed. The Committee developed 68 evidence-based recommendations in 34 categories intended to assist clinicians and patients and counselors, and health policy-makers. Proper surgical treatment selection for oral cancer, which is directed by patient- and subsite-specific factors, remains the greatest predictor of successful treatment outcomes. These guidelines are intended for use in conjunction with the individual patient's treatment goals.
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Humans , Advisory Committees , Bias , Carcinoma, Squamous Cell , Counseling , Expert Testimony , Mouth Neoplasms , Neck , Republic of KoreaABSTRACT
OBJECTIVES: Endoplasmic reticulum (ER) stress is known to be associated with inflammatory airway diseases, and three major transmembrane receptors: double-stranded RNA-activated protein kinase-like ER kinase, inositol requiring enzyme 1, and activating transcription factor 6 (ATF6) play important roles in ER stress-related proinflammatory signaling. However, the effects of ER stress and these three major signaling pathways on the regulation of the production of airway mucins in human nasal airway epithelial cells have not been elucidated. METHODS: In primary human nasal epithelial cells, the effect of tunicamycin (an ER stress inducer) and 4-phenylbutyric acid (4-PBA, ER stress inhibitor) on the expression of MUC5AC and MUC5B was investigated by reverse transcriptasepolymerase chain reaction, real-time polymerase chain reaction, enzyme immunoassay, and immunoblot analysis. Small interfering RNA (siRNA) transfection was used to identify the mechanisms involved. RESULTS: Tunicamycin increased the expressions of MUC5AC and MUC5B and the mRNA expressions of ER stress-related signaling molecules, including spliced X-box binding protein 1 (XBP-1), transcription factor CCAAT-enhancer-binding protein homologous protein (CHOP), and ATF6. In addition, 4-PBA attenuated the tunicamycin-induced expressions of MUC5AC and MUC5B and the mRNA expressions of ER stress-related signaling molecules. Furthermore, siRNA knockdowns of XBP-1, CHOP, and ATF6 blocked the tunicamycin-induced mRNA expressions and glycoprotein productions of MUC5AC and MUC5B. CONCLUSION.: These results demonstrate that ER stress plays an important role in the regulation of MUC5AC and MUC5B via the activations of XBP-1, CHOP, and ATF6 in human nasal airway epithelial cells.
Subject(s)
Humans , Activating Transcription Factor 6 , Carrier Proteins , CCAAT-Enhancer-Binding Proteins , Endoplasmic Reticulum Stress , Endoplasmic Reticulum , Epithelial Cells , Glycoproteins , Immunoenzyme Techniques , Inositol , Mucins , Phosphotransferases , Real-Time Polymerase Chain Reaction , RNA, Messenger , RNA, Small Interfering , Transcription Factor CHOP , Transcription Factors , Transfection , TunicamycinABSTRACT
BACKGROUND AND OBJECTIVES: MUC5AC is one of the major secretory mucin genes in the human airway epithelium. MUC5AC expression is increased by a variety of inflammatory mediators. Protopanaxadiol (PPD), one of the major active metabolites in ginseng, is known to have anti-inflammatory, antitumor and antioxidant properties. However, the effects of PPD on mucin secretion of airway epithelial cells still have not been reported. Therefore, the aim of this study is to investigate the effect of PPD on lipopolysaccharide (LPS)-induced MUC5AC expression in human airway epithelial cells. MATERIALS AND METHOD: In the mucin-producing human NCI-H292 airway epithelial cells, the effect of PPD on MUC5AC expression was investigated using reverse transcription-polymerase chain reaction and enzyme immunoassay after treated with LPS. N-acetylcysteine (NAC) as a reactive oxygen species (ROS) scavenger, and apocynin as a nicotinamide adenine dinucleotide phosphate oxidase inhibitor were used to compare the inhibitory effect of PPD on LPS-induced ROS production in human NCI-H292 cells. RESULTS: LPS significantly increased MUC5AC mRNA expression and protein production. LPS also increased ROS production. PPD inhibited LPS-induced MUC5AC mRNA expression and protein production as well as ROS production. In addition, NAC and apocynin inhibited LPS-induced MUC5AC mRNA expression and protein production. CONCLUSION: These results demonstrate that PPD inhibits LPS-induced MUC5AC expression via ROS in human airway epithelial cells and the inhibitory effect of PPD was similar to that of NAC and apocynin. These findings indicate that PPD may be a therapeutic agent for control of mucus secretion and oxidative stress in human airway epithelial cells.