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폐상피세포에서 Paraquat에 의한 아포프토시스에 관한 연구

Paraquat-Induced Apoptotic Cell Death in Lung Epithelial Cells

Tuberculosis & Respiratory Diseases / Tuberculosis & Respiratory Diseases,
2006, v.61 no.4, pp.366-373
송탁호 (단국의대)
박재석 (단국대학교)
지영구 (단국대학교)
이계영 (건국대학교)
양주연 (단국의대)
정인국 (단국의대)
김윤섭 (단국의대)
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초록

연구배경 : Paraquat는 P-450 reductase에 의해 반응성 산소유리기(ROS)를 발생시켜 세포막, 단백질, 핵산 등과 반응함으로써 세포손상을 유도하며 급성 폐 손상을 일으킨다. 최근 급성 폐 손상 및 급성 호흡곤란 증후군에 있어서 폐상피세포의 아포프토시스가 중요한 역할을 한다고 알려지기 시작하였다. 이에 반응성 산소유리기에 의한 폐 손상의 대표적 물질인 paraquat로 인한 폐상피세포의 세포죽음이 아포프토시스인지 확인하고 dexamethasone, N-acetylcysteine, 그리고 bcl-2가 paraquat로 인한 폐상피 세포죽음에 어떠한 영향을 미치는지 등을 연구하였다.방법 : 폐상피세포주인 A549와 BEAS-2B 세포주, 그리고 bcl-2 construct를 유전자 주입한 A549 pcDNA3-bcl-2 세포주를 이용하였다. 아포프토시스는 Annexin Ⅴ assay를 이용하여서 판정하였으며 세포독성 검사는 MTT assay를 이용하였다. Paraquat는 0, 1 μM, 10 μM, 100 μM, 1 mM, 10 mM의 농도로 사용하였다. Dexamethasone은 1 μM의 농도로 paraquat 투여 12시간 전에 전처치하였고, N-acetylcysteine은 1 mM의 농도로 paraquat 투여 1시간 전에 전처치하였다.결과 : 양 세포주 모두에서 paraquat는 농도와 시간 경과에 따라서 세포죽음을 증가시켰고, 이러한 세포죽음은 아포프토시스였다. N-acetylcysteine과 dexamethasone은 시간과 농도에 따라 약간의 차이가 있으나 전반적으로 10~30%의 방어효과가 있었다. Bcl-2를 과발현시킨 A549-bcl-2 세포주에서 A549-neo 세포주에 비해 paraquat에 의한 세포독성이 약 20~30% 정도 차단되었다.

keywords
Paraquat, Apoptosis, Bcl-2, N-acetylcysteine, Dexamethasone., Paraquat, Apoptosis, Bcl-2, N-acetylcysteine, Dexamethasone.

Abstract

Background: Paraquat is extremely toxic chemical material, which generates reactive oxygen species (ROS), causing multiple organ failure. In particular, paraquat leads to irreversible progressive pulmonary fibrosis. Exaggerated cell deaths exceeding the normal repair of type Ⅱ pneumocytes leads to mesenchymal cells proliferation and fibrosis. This study examined the followings; ⅰ) whether or not paraquat induces cell death in lung epithelial cells; ⅱ) whether or not paraquat-induced cell deaths are apoptosis or necrosis; and ⅲ) the effects of N-acetylcysteine, dexamethasone, and bcl-2 on paraquat-induced cell deaths. Methods: A549 and BEAS-2B lung epithelial cell lines were used. The cell viability and apoptosis were evalluated using a MTT assay, Annexin Ⅴ staining was monitored by fluorescence microscopy, The level of bcl-2 inhibition was examined by establishing stable A549 pcDNA3-bcl-2 cell lines throung the transfection of pcDNA3-bcl-2 with the mock. Results: Paraquat decreased the cell viability in A549 and BEAS-2B cells in a dose and time dependent manner. The Annexin Ⅴ assay showed that apoptosis was the type of paraquat-induced cell death. Paraquat-induced cell deaths was significantly inhibited by N-acetylcysteine, dexamethasone, and bcl-2 overexpression. The cell viability of A549 cells treated with N-acetylcysteine, and dexamethasone on the paraquat-induced cell deaths were increased significantly by 10 ~ 20%, particularly at high doses. In addition, the cell viability of A549 pcDNA3-bcl-2 cells overexpressing bcl-2 was significantly higher than the untransfected A549 cells. Conclusion: Paraquat induces apoptotic cell deaths in lung epithelial cells in a dose and time dependent manner. The paraquat-induced apoptosis of lung epithelial cells might occur through the mitochondrial pathway. (Tuberc Respir Dis 2006; 61: 366-373)

keywords
Paraquat, Apoptosis, Bcl-2, N-acetylcysteine, Dexamethasone., Paraquat, Apoptosis, Bcl-2, N-acetylcysteine, Dexamethasone.

참고문헌

1.

(1983) Evidence for lipid peroxidation by paraquat in the perfused rat lung,

2.

(1984) Paraquat-induced injury of type II alveolar cells,

3.

(1997) Therapeutic effect of hemoperfusion in paraquat poisoning patients,

4.

(tuberrespirdis1994) The effect of aminotriazole on pulmonaty toxicity of paraquat poisoning,

5.

(1995) Fibroblasts isolated after fibrotic lung injury induce apoptosis of alveolar epithelial cells in vitro,

6.

(2001) Fas/FasL-dependent apoptosis of alveolar cells after lipopolysaccharide- induced lung injury in mice,

7.

(1996) The effect of TNF-α gene trasfer on chemosensitivity in lung cancer cells,

8.

(1998) Responses of alveolar macrophages and epithelial type II cells to oxidative DNA damage caused by paraquat,

9.

(1988) Pulmonary reactions and mechanisms of toxicity of inhaled fibers,

10.

(1974) Evidence for energy- dependent accumulation of paraquat into rat lung,

11.

(1997) Apoptosis and expression of Fas/Fas ligand mRNA in bleomycin-induced pulmonary fibrosis in mice,

12.

The American-European Consensus Conference on ARDS,

13.

(1995) Macrophage engulfment of apoptotic neutrophils contributes to the resolution of acute pulmonary inflammation in vivo,

14.

(1995) Apoptosis and loss of renal tissue in polycystic kidney disease,

15.

(2000) Upregulation of two death pathways of perforin/granzyme and FasL/Fas in septic acute respiratory distress syndrome,

16.

(1997) Neutrophil apoptosis in the acute respiratory distress syndrome,

17.

(1990) Intact epithelial barrier function is critical for the resolution of alveolar edema in humans,

18.

(1996) Acute lung injury fibroblast migration and invasion of a fibrin matrix is medigated by CD44,

19.

(1995) Immunosuppression by glucocorticoids:inhibition of NF-kappa B activity through induction of I kappa B synthesis,

20.

(2000) Dexamethasone-induced inhibition of NF-κB transactivation in lung epithelial cells,

21.

(1995) Glutathione homeostasis in alveolar epithelial cells in vitro and lung in vivounder oxidative stress,

22.

(2001) Dexamethasone inhibits spontaneous apoptosis in primary cultures of human and rat hepatocytes via Bcl-2 and Bcl-xL induction,

23.

(1998) Inhibition of angiogenesis and protection from apoptosis by N-acetylcysteine,

24.

(1993) N-acetylcysteine delays the infiltration of inflammatory cells into the lungs of paraquat intoxicated rats,

25.

(1996) N-acetylcysteine increases the glutathione content and protects rat alveolar type II cells against paraquat- induced cytotoxicity,

26.

(1997) Bcl-2 inhibits selective oxidation and externalization of phosphatidylserine during paraquat-induced apoptosis,

27.

(1999) Protection against hydrogen peroxide cytotoxicity in Rat-1 fibroblasts provided by the oncoprotein Bcl-2:maintenance of calciumhomeostasis is secondary to the effect of Bcl-2 on cellular glutathione,

28.

(1997) The potential role of Bax and Bcl-2 expression in diffuse alveolar damage,

Tuberculosis & Respiratory Diseases