The Role of Neutrophils and Epidermal Growth Factor Receptors in Lipopolysaccharide-Induced Mucus Hypersecretion / 결핵

BACKGROUND: Goblet cell hyperplasia is a critical pathological feature in hypersecretory diseases of the airways. A bacterial infection of the lung is also known to induce inflammatory responses, which can lead to the overproduction of mucus. Recently, mucin synthesis in the airways has been reported to be regulated by neutrophilic inflammation-induced epidermal growth factor receptor (EGFR) expression and activation. In addition, it was reported that migration of the activated neutrophils is dependent on the matrix metalloproteinases (MMPs), especially MMP-9. In this study, bacterial lipopolysaccharide (LPS)-induced goblet cell hyperplasia and mucus hypersecretion by EGFR cascade, resulting from the MMPs-dependent neutrophilic inflammation were investigated in the rat airways. METHODS: Pathogen-free Sprague-Dawley rats were studied in vivo. Various concentrations of LPS were instilled into the trachea in 300microliter PBS (LPS group). Sterile PBS (300microliter) was instilled into the trachea of the control animals (control group). The airways were examined on different days after instilling LPS. For an examination of the relationship between the LPS-induced goblet cell hyperplasia and MMPs, the animals were pretreated 3 days prior to the LPS instillation and daily thereafter with the matrix metalloproteinase inhibitor (MMPI; 20 mg/Kg/day of CMT-3; Collagenex Pharmaceuticals, USA). The neutrophilic infiltration was quantified as a number in five high power fields (HPF). The alcian blue/periodic acid-Schiff (AB/PAS) stain were performed for the mucus glycoconjugates and the immunohistochemical stains were performed for MUC5AC, EGFR and MMP-9. Their expressions were quantified by an image analysis program and were expressed by the percentage of the total bronchial epithelial area. RESULTS: The instillation of LPS induced AB/PAS and MUC5AC staining in the airway epithelium in a time- and dose-dependent manner. Treatment with the MMPI prevented the LPS-induced goblet cell hyperplasia significantly. The instillation of LPS into the trachea induced also EGFR expression in the airway epithelium. The control airway epithelium contained few leukocytes, but the intratracheal instillation of LPS resulted in a neutrophilic recruitment. A pretreatment with MMPI prevented neutrophilic recruitment, EGFR expression, and goblet cell hyperplasia in the LPS-instilled airway epithelium. CONCLUSION: Matrix metalloproteinase is involved in LPS-induced mucus hypersecretion, resulting from a neutrophilic inflammation and EGFR cascade. These results suggest a potential therapeutic role of MMPI in the treatment of mucus hypersecretion that were associated with a bacterial infection of the airways.

The Role of Neutrophils and Epidermal Growth Factor Receptors in Lipopolysaccharide-Induced Mucus Hypersecretion / 결핵

BACKGROUND: Goblet cell hyperplasia is a critical pathological feature in hypersecretory diseases of the airways. A bacterial infection of the lung is also known to induce inflammatory responses, which can lead to the overproduction of mucus. Recently, mucin synthesis in the airways has been reported to be regulated by neutrophilic inflammation-induced epidermal growth factor receptor (EGFR) expression and activation. In addition, it was reported that migration of the activated neutrophils is dependent on the matrix metalloproteinases (MMPs), especially MMP-9. In this study, bacterial lipopolysaccharide (LPS)-induced goblet cell hyperplasia and mucus hypersecretion by EGFR cascade, resulting from the MMPs-dependent neutrophilic inflammation were investigated in the rat airways. METHODS: Pathogen-free Sprague-Dawley rats were studied in vivo. Various concentrations of LPS were instilled into the trachea in 300microliter PBS (LPS group). Sterile PBS (300microliter) was instilled into the trachea of the control animals (control group). The airways were examined on different days after instilling LPS. For an examination of the relationship between the LPS-induced goblet cell hyperplasia and MMPs, the animals were pretreated 3 days prior to the LPS instillation and daily thereafter with the matrix metalloproteinase inhibitor (MMPI; 20 mg/Kg/day of CMT-3; Collagenex Pharmaceuticals, USA). The neutrophilic infiltration was quantified as a number in five high power fields (HPF). The alcian blue/periodic acid-Schiff (AB/PAS) stain were performed for the mucus glycoconjugates and the immunohistochemical stains were performed for MUC5AC, EGFR and MMP-9. Their expressions were quantified by an image analysis program and were expressed by the percentage of the total bronchial epithelial area. RESULTS: The instillation of LPS induced AB/PAS and MUC5AC staining in the airway epithelium in a time- and dose-dependent manner. Treatment with the MMPI prevented the LPS-induced goblet cell hyperplasia significantly. The instillation of LPS into the trachea induced also EGFR expression in the airway epithelium. The control airway epithelium contained few leukocytes, but the intratracheal instillation of LPS resulted in a neutrophilic recruitment. A pretreatment with MMPI prevented neutrophilic recruitment, EGFR expression, and goblet cell hyperplasia in the LPS-instilled airway epithelium. CONCLUSION: Matrix metalloproteinase is involved in LPS-induced mucus hypersecretion, resulting from a neutrophilic inflammation and EGFR cascade. These results suggest a potential therapeutic role of MMPI in the treatment of mucus hypersecretion that were associated with a bacterial infection of the airways.

Sodium Salicylate(NaSaL) Induces Apoptosis of NCI-H1299 Lung Carcinoma Cells via Activation Caspase-3 Protease / 결핵

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) are useful in the chemoprevention of colon cancers. Continuous NSAID use results in a 40% to 50% reduction in the relative risk of colorectal cancer. The precise mechanism by which NSAIDs prevent and /or cause the regression of colorectal tumors is not known. Some investigators have reported that certain NSAIDs induce apoptosis and alter the expression of the cell cycle regulatory genes in some carcinoma cells when administered at a relatively high concentration. However, the possibility of NSAIDs application as chemopreventive agents in lung cancers remains to be elucidated. To address this question, the human lung cancer cell line NCI-H1299 was used to investigate whether or not NSAIDs might induce the apoptotic death of NCI-H1299 cells. METHOD: A viability test was carried out using a MTT assay. Apoptosis was measured by flow cytometric analysis and nuclear staining(DAPI). The catalytic activity of the caspase family was measured by the fluorogenic cleavage of biosubstrates. To define the mechanical basis of apoptosis, western blot was performed to analyze the expression of the cleavage of the death substrates(PARP and ICAD). RESULTS: NaSaL significantly decreased the viability of the NCI-H1299 cells, which was revealed as apoptosis characterized by an increase in the subG0/G1 population and nuclear fragmentation. The catalytic activity of caspase-3 protease began to increase after 24 Hr and reached a peak 30 Hr after treatment with 10 mM NaSaL. In contrast, caspase-6, 8, and 9 proteases did not have a significantly altered enzymatic activity. Consistent with activation of caspase-3 protease, NaSaL induced the cleavage of the protease biosubstrate. CONCLUSION: NaSaL induces the apoptotic death of NCI-H1299 human lung cancer cells via the activation of caspase-3 protease.

A Case of Cryoglobulinemia-induced Acute Respiratory Distress Syndrome / 결핵

Cryoglobulinemia is the presence of globulins in the serum that precipitate on exposure to cold temperatures (cryoglobulins). Pulmonary complications of cryoglobulinemia include interstial infiltration, impaired gas exchange, small airway disease and pleurisy. Only one other acute respiratory distress syndrome(ARDS) case has been described in patients with cryoglobulinemia. A 55-years old man was admitted with dyspnea. He had been diagnosed as being a hepatitis B virus antigen carrier 15 years age. On the first admission, chest radiography showed a bilateral pleural effusion and a patchy infiltration on both lungs. On protein-and immuno-electrophoresis, cryoglobulinemia was confirmed. The patient was treated with corticosteroid and plasmapheresis. Forty-five days after the diagnosis, the patient complained of progressive dyspnea and showed a diffuse bilateral pulmonary infiltration on chest radiography. Despite intensive care with mechanical ventilation, the patient died as consequence of hypoxemia and multiple systemic organ failure. On a pathologic examination of the postmortem lung biopsy, multiple necrotizing vasculitis and increased infiltration of the lymphocytes and monocytes were observed. In conclusion, ARDS developed as a result of pulmonary hemorrhage due to cryoglobulinemia-associated vasculitis.

Clinical Study fo Pulmonary Thromboembolism / 결핵

BACKGROUND: Pulmonary thromboembolism is relatively frequent and potentially fatal. However, it is commonly misdiagnosed. The incidence of pulmonary thromboembolism is not decreasing despite advances in diagnosis and effective prophylatic measures. Its potential for significant sequela necessitates a prompt diagnosis and treatment. Unfortunately, there are many difficulties and problems regarding accurate diagnosis. There is a low prevalence of deep vein thrombosis and pulmonary thromboembolism in Korea and only few reports on this subject are available. METHOD: The clinical features of 36 patients, who were diagnosed with pulmonary thromboembolism at the Korea University medical center, were reviewed. RESULTS: 1) There was no significant difference in prevalence between men an women, and the mean age was 50.9 years in men 59.2 years in women. 2) The frequent causes of pulmonary thromboembolism were malignancies (22.2%), surgery (22.2%), and heart disease(8.2%). Specific causes were not identified in 33.3%. 3) The most common symptom was dyspnea(72.2%), and the most common sign was tachypnea(61.1%). 4) The EKG findings were normal in 28.6%, and S1Q3T3 pulmonale pattern in 25.7%, ST or QRS changes in others. 5) The chest X-ray findings indicated pulmonary infiltation in 37.5%, cardiomegaly in 15.6%, pleural effusion in 12.5%, and normal in 27.8%. The perfusion lung scan showed a high probability in 66.7%, and intermediate or low probability in 33.3%. 6) The pulmonary arterial pressure(PAP) in the high probability groups was 57.9mmHg with a higher mortality rate(35%). CONCLUSION: Pulmonary thromboembolism is not uncommon in Korea and its clinical features do not differ greatly from those reported in the literature. When pulmonary thromboemblism of unknown causes are diagnosed, a search for an occult malignancy is recommended. Rapid diagnosis and treatment are achieved when thromboemblism is suspected.

Myxoid Leiomyosarcoma of the Superior Vena Cava Syndrome / 결핵

A 38-year-old woman presented with facial edema with neck vein engorgement for about 45 days. Chest roentgenography showed bulging soft tissue opacities in the right superoanterior mediastinum and a lobulated intraluminal mass was noted in the superior vena cava on the venacavogram. The superior vena cava was incised and the tumor located from the junction of the superior vena cava and internal jugular vein to the right atrial inlet was excised. Grossly, the tumor was myxoid or gelatinous in appearance. A combination of microscopic and immunohistochemical features showed myxoid leiomyosarcoma arising from the wall of the superior vena cava.

Function of the neuronal M2 muscarinic receptor in asthmatic patients / 결핵

BACKGROUND: The dominant innervation of airway smooth muscle is parasympathetic fibers which are carried in the vagus nerve. Activation of these cholinergic nerves releases acetylcholine which binds to M3 muscarinic receptors on the smooth muscle causing bronchocontraction. Acetylcholine also feeds back onto neuronal M2 muscarinic receptors located on the postganglionic cholinergic nerves. Stimulation of these receptors further inhibits acetylcholine release, so these M2 muscarinic receptors act as autoreceptors. Loss of function of these M2 receptors, as it occres in animal models of hyperresponsiveness, leads to an increase in vagally mediated hyperresponsiveness. However, there are limited data pertaining to whether there are dysfunctions of these receptors in patients with asthma. The aim of this study is to determine whether there are dysfunction of M2 muscarinic receptors in asthmatic patients and difference of function of these receptors according to severity of asthma. METHODS: We studied twenty-seven patients with asthma who were registered at Pulmonology Division of Korea University Hospital. They all met asthma criteria of ATS. Of these patients, eleven patients were categorized as having mild asthma, eight patients moderate asthma and eight patients severe asthma according to severity by NAEPP Expert Panel Report 2(1997). All subjects were free of recent upper respiratory tract infection within 2 weeks and showed positive methacholine challenge test(PC 20<16mg/ml). Methacholine provocation tests performed twice on separate days allowing for an interval of one week. In the second test, pre-treatment with the M2 muscarinic receptor agonist pilocarpine(180µg) through inhalation was performed before the routine procedures. RESULTS: Eleven subjects with mild asthma and eight aubjects with moderate asthma showed significant increase of PC20 from 5.30±5.23mg/ml(mean±SD) to 20.82±22.56mg/ml(p=0.004) and from 2.79±1.5mg/ml to 4.67±3.53mg/ml(p=0.012) after pilocarpine inhalation, respectively. However, in the eight subjects with severe asthma significant increase of PC20 from 1.76±1.50mg/ml to 3.18±4.03mg/ml(p=0.161) after pilocarpine inhalation was not found. CONCLUSION: In subjects with mild and moderate asthma, function of M2 muscarinic receptors was normal, but there was a dysfunction of these receptors in subjects with severe asthma. These results suggest that function of M2 muscarinic receptors is different according to severity of asthma.