Jung-Sun Cho

Epigenetic regulation of myofibroblast differentiation and extracellular matrix production in nasal polyp-derived fibroblasts.

Nasal polyposis is a multi‐factorial disease associated with chronic inflammatory condition of the paranasal sinuses. Myofibroblast differentiation and extracellular matrix (ECM) accumulation are involved in the pathogenesis of nasal polyposis.

Lipopolysaccharide Induces Pro-Inflammatory Cytokines and MMP Production via TLR4 in Nasal Polyp-Derived Fibroblast and Organ Culture

Nasal polyposis is characterized by persistent inflammation and remodeling in sinonasal mucosa. Toll-like receptors (TLRs) play a role in the innate immune response to microbes in the sinonasal cavity. The aim of this study was to evaluate whether nasal polyp-derived fibroblasts (NPDFs) and organ-cultured nasal polyps can synthesize pro-inflammatory cytokines and matrix metalloproteinases (MMPs) after exposure to lipopolysaccharide (LPS), a TLR4 agonist. NPDFs and organ-cultured nasal polyps were isolated from nasal polyps of 8 patients and exposed to LPS. The mRNA and protein expression levels of TLRs, cytokines, and MMPs were determined using a gene expression microarray, real-time RT-PCR, western blot analysis, enzyme-linked immunosorbent assay, and immunofluorescence staining. The enzymatic activities of MMPs were analyzed using collagen or gelatin zymography. The protein expression level of MMP-1 increased in nasal polyp tissues compared to inferior turbinate tissues. LPS induced mRNA expression of TLR4, IL-6, IL-8, and MMP-1 and activated MAPK signaling in NPDFs. LPS promoted the release of interleukin (IL)-6 through extracellular signal-related kinase (ERK) and IL-8 through ERK and c-Jun N-terminal kinases (JNK). Production of IL-6 and IL-8 was induced by PI3K/Akt signaling in LPS-stimulated NPDFs. LPS increased the transcript and protein expression levels of MMP-1 and induced collagenase activity of MMP-1 via ERK and p38, but did not induce gelatinase activity of MMP-2 and MMP-9. LPS from Rhodobacter sphaeroides (LPS-RS) inhibited the stimulatory effects of LPS in NPDFs as well as in organ culture of nasal polyp. LPS triggers immune response via TLR 4 and activates MAPK and PI3K/Akt signaling pathway, which is involved in remodeling of nasal polyps.

Activation of TLR4 induces VEGF expression via Akt pathway in nasal polyps

Nasal polyposis is characterized by tissue remodelling and oedematous nasal mucosa. Vascular endothelial growth factor (VEGF) plays a significant role in the regulation of remodelling in nasal polyps. TLR4 activation is associated with VEGF expression in murine macrophages and odontoblasts.

Rhinitis, sinusitis and ocular disease – 2086. Nox4 mediates hypoxia-stimulated myofibroblast differentiation in nasal polyp-derived fibroblasts.

Background Chronic hypoxia is associated with remodeling in various organs. Reactive oxygen species (ROS) derived from NADPH oxidases (Nox), and TGF-beta1 have been implicated in the pathogenesis of hypoxia-induced remodeling. The aims of this study were to determine in hypoxiastimulated nasal polyp-derived fibroblasts (NPDF) the effect of hypoxia on the differentiation of myofibroblasts, the role of ROS, the major Nox homolog mediating myofibroblast differentiation, and the role of TGF-beta1. Methods Eight primary cultures of NPDF were established from nasal polyps, which were incubated under hypoxic conditions. Reverse transcription polymerase chain reaction for alpha-SMA, Nox1, Nox3, Nox4, Nox5 ,a ndfibronectin mRNA was performed. Western blotting for alpha-SMA and fibronectin was done. ROS production was detected using a fluorometer. NPDF were pretreated with ROS scavengers and transfected with siNox4. The TGF-beta1 protein level was measured by ELISA. The effect of treatment with TGF-beta1 type I tyrosine kinase inhibitor SB431542 on myofibroblast differentiation was ob-served. Results Hypoxic stimulation of NPDF significantly increased alpha-SMA and fibronectin mRNA and protein expression. ROS production was increased by hypoxia, and ROS scavengers inhibited myofibroblast differentiation. Nox4 mRNA was the only Nox homolog increased by hypoxia. Transfection with siNox4 inhibited myofibroblast differentiation. TGF-beta1 was secreted endogenously by hypoxic NPDF. SB431542 significantly inhibited myofibroblast differentiation. Conclusions Hypoxia induces myofibroblast differentiation of NPDF through a signaling pathway involving Nox4-dependent ROS generation and TGF-beta1. Therapies targeting Nox4 may be effective against remodeling of nasal polyps.

AMPK Inhibits TGF-β1–Induced Extra Cellular Matrix Production in Nasal Polyp-Derived Fibroblast

Objectives: Adenosine monophosphate-activated protein kinase (AMPK) is known to inhibit fibrogenic responses in many cells by targeting TGF-Î21-Smad signaling. The purpose of this study was to investigate the effect of AMPK on TGF-Î21-induced myofibroblast differentiation and ECM production and to determine the underlying mechanism for the action of AMPK in nasal polyp-derived fibroblasts (NPDFs). Methods: NPDFs were incubated with TGF-β1 and treated with the activator of AMPK (metformin) or inhibitor of AMPK (compound C). To determine the proliferation rate of nasal fibroblasts, MTT assay was performed. The expression levels of α-smooth muscle actin and fibronectin were determined by reverse transcription polymerase chain reaction (RT-PCR), Western blotting and immunofluorescent staining. Phosphorylation of AMPK and phosphorylation of Smad2/3 were evaluated by Western blot analysis. Results: In TGF-β1-induced NPDFs, metformin inhibited the expression of α-SMA and fibronectin, as confirmed by both RT-PCR and Western blotting analysis. Metformin increased the phosphorylation of AMPK and expression levels of α-SMA and fibronectin, and compound C reversed these effects. Metformin inhibited TGF-β1-induced phosphorylation of Smad2/3. Conclusions: This study showed that AMPK inhibited TGF-β1-induced ECM production in NPDFs via the Smad2/3 pathway. AMPK can be a therapeutic target for the prevention of ECM remodeling in nasal polyps.

The Effect of Macrolides in Nasal Polyp-Derived Fibroblasts

the middle ear may have a modulatory effect on the establishment of the allergic conditions that facilitate recurrent otitis media with effusion and Eustachian tube (ET) dysfunction. Our objectives were to: 1) Establish allergic ET dysfunction in rats via transtympanic (TT) exposure to ovalbumin (OVA). 2) Modulate the nature of the immune response to OVA by varying the concentration of LPS. 3) Understand the role of LPS exposure in the middle ear on the development of allergy. METHOD: Brown-Norway rats were randomized to four groups: I) non-allergic control; II) OVA only; III) OVA and low-dose LPS; and IV) OVA and high-dose LPS. Group I received TT phosphate-buffered saline, while group II received TT OVA. Groups III and IV received TT OVA and simultaneously received either low-dose TT LPS or high-dose TT LPS. All groups were transtympanically challenged with OVA two weeks after initial exposure. Immediately after OVA challenge, the dynamic function of the ET was assessed by the following measures: passive opening pressure, passive closing pressure, and mucociliary transit time. These measures were analyzed across groups by ANOVA. Statistical significance was determined prior to the experiment for p values of 0.05 and a power of 0.80. RESULTS: The low-dose LPS group was found to have significantly increased passive opening pressures, passive closing pressures, and mucociliary clearance times (p0.05). CONCLUSION: Results indicate that the presence of LPS in the middle ear during antigen presentation has an effect on the immune response to that antigen, and that the nature of the effect varies with LPS concentration. Specifically, low doses of LPS appear to augment the development of allergy when presented simultaneously with OVA, while high doses of LPS appear to inhibit the development of allergy.

Effect of Flavonoids in Nasal Polyp-Derived Fibroblasts

positive histamine controls were used. All patients denied food anaphylaxis. A wheal was taken to be positive when it was at least 2 mm larger in average diameter than the concentrationmatched glycerine control after 10 minutes. Patients were counselled by a dietician and subsequently put on diet control therapy. RESULTS: 21% (n 143) of patients reported poor to slight improvement. 29.4 % (n 200) reported better improvement. 49.6 % (n 337) reported good to very good improvement. Treatment success was most likely with patients with egg allergy (51.7%), milk allergy (46.6%) and wheat allergy (45.2%). Treatment results were significantly poorer in patients with allergies to garlic (30.8%), soy, (33.1%) and malt (38.4%). CONCLUSION: Strict diet control without pharmacotherapy is effective in the management of patients with food-induced allergic rhinitis. This reduces the usage of pharmacotherapy, alleviating the economic burden associated with allergic rhinitis. Discriminate choice of patients is imperative towards ensuring treatment success with strict diet control.

Expression of EMMPRIN in Nasal Polyps

charts, intraoperative images, and surgical videos were reviewed. The indications for the endoscopic approach, surgical technique, and postoperative course are described. RESULTS: Both lesions in this study were adjacent to the posterior sphenoid wall and medial to the paraclival carotid artery. Each lesion was resected using a transpterygoid approach to gain lateral and inferior access to the sphenoid and exposure of the paraclival carotid arteries. In both cases, wide openings into the petrous apex were achieved. Both patients presented with headache as their chief complaint and both had resolution of their symptoms following successful minimally invasive endoscopic resection. The two petrous apex lesions were diagnosed as cholesterol granuloma and bony osteoma. CONCLUSION: The expanded endonasal approach is safe and effective for resection of petrous apex lesions. This technique may provide larger drainage pathways and decreased risk to hearing and the facial nerve than the traditional transmastoid approaches.