• Title/Summary/Keyword: Bak activation

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Anticarcinogenic Effects of Extracts from Gloiopeltis tenax (참가사리 분획물의 암 예방효과)

  • Jung, Young-Hwa;Jung, Bok-Mi;Shin, Mi-Ok;Bae, Song-Ja
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.4
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    • pp.395-401
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    • 2006
  • In this study, we investigated anticarcinogenic effects of extracts from Gloiopeltis tenax (GT). GT was extracted with methanol (GTM), which was then further fractionated into four fractions by using solvent fractionation method, affording methanol (GTMM), hexane (GTMH), butanol (GTMB) and aqueous (GTMA) soluble fractions. We determined the cytotoxic effects of these fractions on cancer cells by MTT assay. Among various fractions of GT, the GTMM showed the strongest cytotoxic effect at concentration of $150{\mu}g/mL$, displaying 95.97% on HepG2 cell lines and 93.64% on HT-29 cell lines, respectively. And, the anti-proliferative effect of GT was accompanied by a marked in increase of levels of Bad, Bax, Bok and Bak protein and activation of caspase-3, caspase-7 and PARP protein. Also, we observed quinone reductase (QR) induced effects in all fraction layers of GT on HepG2 cells. The QR induced effects of the GTMM and GTMB on HepG2 cells at concentration of $60{\mu}g/mL$ showing inductive indexes of 2.86 and 2.04 compared to the control value of 1.0.

The Role of Neutrophils and Epidermal Growth Factor Receptors in Lipopolysaccharide-Induced Mucus Hypersecretion (리포다당질 (lipopolysaccharide)에 의한 기관지 점액 생성 기전에서 호중구와 상피세포 성장인자 수용체 (epidermal growth factor receptor)의 역할)

  • Bak, Sang Myeon;Park, Soo Yeon;Hur, Gyu Young;Lee, Seung Heon;Kim, Je Hyeong;Lee, Sang Yeub;Shin, Chol;Shim, Jae Jeong;In, Kwang Ho;Kang, Kyung Ho;Yoo, Se Hwa
    • Tuberculosis and Respiratory Diseases
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    • v.54 no.1
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    • pp.80-90
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    • 2003
  • 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 $300{\mu}{\ell}$ PBS (LPS group). Sterile PBS ($300{\mu}{\ell}$) 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.

Function of the Neuronal $M_2$ Muscarinic Receptor in Asthmatic Patients (천식 환자에서 $M_2$ 무스카린성 수용체 기능에 관한 연구)

  • Kwon, Young-Hwan;Lee, Sang-Yeup;Bak, Sang-Myeon;Lee, Sin-Hyung;Shin, Chol;Cho, Jae-Youn;Shim, Jae-Jeong;Kang, Kyung-Ho;Yoo, Se-Hwa;In, Kwang-Ho
    • Tuberculosis and Respiratory Diseases
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    • v.49 no.4
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    • pp.486-494
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    • 2000
  • 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 $M_3$ muscarinic receptors on the smooth muscle causing bronchocontraction. Acetylcholine also feeds back onto neuronal $M_2$ muscarinic receptors located on the postganglionic cholinergic nerves. Stimulation of these receptors further inhibits acetylcholine release, so these $M_2$, muscarinic receptors act as autoreceptors. Loss of function of these $M_2$ receptors, as it occurs 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 $M_2$ muscarinic receptors in asthmatic patients and difference of function of these receptors according to severity of asthma. Method : 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 were performed twice on separate days allowing for an interval of one week. In the second test, pretreatment with the $M_2$ muscarinic receptor agonist pilocarpine($180{\mu}g$) through inhalation was performed be fore the routine procedures. Results : Eleven subjects with mild asthma and eight subjects with moderate asthma showed significant increase of $PC_{20}$ from 5.30$\pm$5.23mg/ml(mean$\pm$SD) to 20.82$\pm$22.56mg/ml(p=0.004) and from 2.79$\pm$1.51mg/ml to 4.67$\pm$3.53mg/ml(p=0.012) after pilocarpine inhalation, respectively. However, in the eight subjects with severe asthma significant increase of $PC_{20}$ from l.76$\pm$1.50mg/ml to 3.18$\pm$4.03mg/ml(p=0.161) after pilocarpine inhalation was not found. Conclusion : In subjects with mild and moderate asthma, function of $M_2$ muscarinic receptors was normal, but there was a dysfunction of these receptors in subjects with severe asthma. ηlese results suggest that function of $M_2$ muscarinic receptors is different according to severity of asthma.

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