title: The antioxidant, taurine reduced lipopolysaccharide (LPS)-induced generation of ROS, and activation of MAPKs and Bax in cultured pneumocytes.
abstract: Lipopolysaccharide (LPS) can cause damage to the epithelia of the respiratory tract. However, taurine can protect the lung tissue from such oxidant-induced inflammation. This study examined the effects of a LPS treatment on the intracellular calcium levels ([Ca(2+)]i) as well as the specific mechanisms of LPS-induced cell death in pneumocytes. In addition, the effects of taurine on the LPS-induced increase in the accumulation of reactive oxygen species (ROS) in pneumocytes were investigated. The [Ca(2+)]i in cultured pneumocytes was determined using microfluorescence techniques. The level of activation of the mitogen-activated protein kinases (MAPKs) and Bax protein were measured by Western blotting. LPS at 10 and 100 ng/ml induced cell death and decreased the viability of MRC-5 cells. Moreover, the intracellular Ca(2+) and ROS levels were increased by LPS. The LPS treatment led to the phosphorylation of ERK1/2, JNK and the activation of Bax. A pretreatment with 20 mM taurine reduced the LPS-induced production of ROS and MARK activity. These results show that a LPS treatment induces cell death in MRC-5 cells by increasing the intracellular ROS and Ca(2+) levels. The increase in the intracellular level of ROS promotes MAPKs activation and Bax translocation. Overall, LPS induces lung cell death by activating MAPKs. Furthermore, taurine decreased the LPS-induced generation of ROS and activation of MAPK and Bax.
authors: Department of Pharmacology and Toxicology, College of Veterinary Medicine, Chonbuk National University, Jeonju 561-756, Republic of Korea.
authors: Seol-Hee
authors: SH
authors: Jeon
authors: Mun-Young
authors: MY
authors: Lee
authors: Md Mizanur
authors: MM
authors: Rahman
authors: Shang-Jin
authors: SJ
authors: Kim
authors: Gi-Beum
authors: GB
authors: Kim
authors: Sang-Youel
authors: SY
authors: Park
authors: Chul-Un
authors: CU
authors: Hong
authors: Sung-Zoo
authors: SZ
authors: Kim
authors: Jin-Shang
authors: JS
authors: Kim
authors: Hyung-Sub
authors: HS
authors: Kang
mesh_terms: D056809:Alveolar Epithelial Cells / Q000187:drug effects*; D000975:Antioxidants / Q000494:pharmacology*; D020013:Calcium Signaling / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004396:Coloring Agents; D004789:Enzyme Activation / Q000187:drug effects; D005347:Fibroblasts / Q000187:drug effects; D006801:Humans; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D008168:Lung / Q000166:cytology* / Q000187:drug effects; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013654:Taurine / Q000494:pharmacology*; D013778:Tetrazolium Salts; D013844:Thiazoles; D051028:bcl-2-Associated X Protein / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D004396:Coloring Agents; D008070:Lipopolysaccharides; D017382:Reactive Oxygen Species; D013778:Tetrazolium Salts; D013844:Thiazoles; D051028:bcl-2-Associated X Protein; D013654:Taurine; D020928:Mitogen-Activated Protein Kinases; C022616:thiazolyl blue