title: Studies on mitogen-activated protein kinase signaling pathway in the alveolar macrophages of chronic bronchitis rats.
abstract: Lipopolysaccharide (LPS), a potent stimulator of inflammatory responses in alveolar macrophages (AMs), activates several intracellular signaling pathways, including mitogen-activated protein kinases (MAPK). In the present study, we investigated the MAPK pathway in AMs of chronic bronchitis (CB) rats. CB was induced by endotracheal instillation of LPS followed by Bacillus Calmette Guerin injection through the caudal vein 1 week later. Specific inhibitors were used and protein phosphorylations were detected by Western blot. We found that Genistein (PTK inhibitor) could inhibit protein kinase C (PKC), phosphatidylinositol-3 kinase (PI3K)/protein kinase B (Akt or PKB) MAPK signaling pathway with different degrees, LY294002 (PI3K inhibitor) could not only inhibit phospho-PI3K/Akt expression, but also inhibit p38 and c-Jun NH2-terminal kinases (JNK) phosphorylation. Calphostin C (PKC inhibitor) could inhibit phospho-PKC expression and exerted significant effects on extracellular signal-regulated kinases (ERK) phosphorylation, however, it had no impact on p38 and JNK phosphorylation. These results demonstrated that the LPS mediated signaling pathway of MAPK in AMs of CB rats could be described as follows: PTK-PI3K-Akt-JNK/p38 or PTK-PI3K-PKC-ERK, and PI3K may have a negative regulation on the activation of downstream proteins.
authors.affiliation: School of Pharmacy, Anhui Medical University, Tunxi West Road, Hefei, 230032, Anhui, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Huang
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Meng
authors.forename: Guo-Lin
authors.initials: GL
authors.lastname: Jiang
authors.forename: Ya-Ru
authors.initials: YR
authors.lastname: Yang
authors.forename: Juan
authors.initials: J
authors.lastname: Liu
authors.forename: Xiong-Wen
authors.initials: XW
authors.lastname: Lv
authors.forename: Jun
authors.initials: J
authors.lastname: Li
mesh_terms: D000818:Animals; D029481:Bronchitis, Chronic / Q000139:chemically induced / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D005786:Gene Expression Regulation / Q000187:drug effects; D019833:Genistein / Q000008:administration & dosage*; D006801:Humans; D008070:Lipopolysaccharides / Q000633:toxicity; D048670:MAP Kinase Kinase 4 / Q000096:biosynthesis; D016676:Macrophages, Alveolar / Q000378:metabolism* / Q000473:pathology; D008297:Male; D020929:Mitogen-Activated Protein Kinase Kinases / Q000235:genetics*; D058539:Phosphatidylinositol 3-Kinase / Q000096:biosynthesis; D011493:Protein Kinase C / Q000096:biosynthesis; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects; D048051:p38 Mitogen-Activated Protein Kinases / Q000096:biosynthesis
chemical_list: D008070:Lipopolysaccharides; D019833:Genistein; D058539:Phosphatidylinositol 3-Kinase; D011493:Protein Kinase C; D048051:p38 Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases