17β-estradiol attenuates homocysteine-induced oxidative stress and inflammatory response as well as MAPKs cascade via activating PI3-K/Akt signal transduction pathway in Raw 264,7 cells  

作　　者：Ying Zhang Ying He Yi Zong Jiazhi Guo Lin Sun Yunbing Ma Wei Dong Li Gui 

机构地区：[1]Department of Pathophysiology, Basic Medical School, Kunming Medical University, Kunming 650500, China [2]Department of Anatomy, Basic Medical School, Kunming Medical University,Kunming 650500, China [3]Department of Cardiology, The Second Affiliated Hospital, Kunrning Medical University, Kunming 650101, China [4]Department of Endocrinology, The Third People's Hospital of Yunnan Province, Kunming 650011, China [5]Department of Orthopedics, The Third Affiliated Hospital, Yunnan Traditional Chinese Medicine College, Kunming 650031, China

出　　处：《Acta Biochimica et Biophysica Sinica》2015年第2期65-72,共8页生物化学与生物物理学报（英文版）

基　　金：This work was supported by the grants from the National Natural Science Foundation of China （Nos. 81460173, 81260061 and 81260297）, the Yunnan Applied Basic Research Projects-Joint Special Project （Nos. 2012FB013 and 2013FB101）, and the Key Project of Yunnan Provincial Education Commission （No. 2014Z128）.

摘　　要：Oxidative stress, inflammatory response, and mitogen-activated protein kinases （MAPKs） cascade are significant pathogenic factors of osteoporosis. It has been reported that elevated homocysteine （Hcy） may activate oxidative stress and reduce bone mineral density in post-menopausal osteopor- osis. Moreover, hormone replacement therapy has been widely used in clinic to prevent and treat post-menopausal women with osteoporosis and osteoporotic fracture, but the molecular mechan- isms and relevant signal transduction pathways underlying the action of Hcy remain unclear. In this study, we investigated the effects of 17β-estradiol （17β-E2） on the Hcy-induced oxidative stress, inflammatory response and MAPKs cascade, as well as the underlying signal transduction pathway in murine Raw 264.7 cells. The reactive oxygen species （ROS） was assessed by fluorospectrophoto- metry. The proinflammatory cytokines tumor necrosis factor-α （TNF-α） and interleukin （IL）-1β were analyzed by double-immunofluorescence labeling and reverse transcriptase polymerase chain reac- tion assay, respectively. Furthermore, phosphorylation levels of MAPKs cascade were measured by western blot analysis. A specific phosphatidylinositol 3-kinase （PI3-K） inhibitor, Wortmannin （1 μM） was employed to determine whether PI3-K/Akt signaling pathway mediated the 17β-E2＇s effect on Raw 264.7 cells. 171β-E2 markedly decreased the ROS production induced by Hcy, the expression of TNF-α and IL-1β at protein and mRNA levels, and down-regulated the phosphorylation of MAPKs （ERK1/2, JNK and p38）. These suppressing effects of 17β-E2 on Hcy-induced changes were reversed by pretreatment with PI3-K inhibitor Wortmannin. The results indicate that 17β-estradiol may attenu- ate Hcy-induced oxidative stress, inflammatory response and up-regulation of MAPKs in Raw 264.7 cells via PI3-K/Akt signal transduction pathway.Oxidative stress, inflammatory response, and mitogen-activated protein kinases （MAPKs） cascade are significant pathogenic factors of osteoporosis. It has been reported that elevated homocysteine （Hcy） may activate oxidative stress and reduce bone mineral density in post-menopausal osteopor- osis. Moreover, hormone replacement therapy has been widely used in clinic to prevent and treat post-menopausal women with osteoporosis and osteoporotic fracture, but the molecular mechan- isms and relevant signal transduction pathways underlying the action of Hcy remain unclear. In this study, we investigated the effects of 17β-estradiol （17β-E2） on the Hcy-induced oxidative stress, inflammatory response and MAPKs cascade, as well as the underlying signal transduction pathway in murine Raw 264.7 cells. The reactive oxygen species （ROS） was assessed by fluorospectrophoto- metry. The proinflammatory cytokines tumor necrosis factor-α （TNF-α） and interleukin （IL）-1β were analyzed by double-immunofluorescence labeling and reverse transcriptase polymerase chain reac- tion assay, respectively. Furthermore, phosphorylation levels of MAPKs cascade were measured by western blot analysis. A specific phosphatidylinositol 3-kinase （PI3-K） inhibitor, Wortmannin （1 μM） was employed to determine whether PI3-K/Akt signaling pathway mediated the 17β-E2＇s effect on Raw 264.7 cells. 171β-E2 markedly decreased the ROS production induced by Hcy, the expression of TNF-α and IL-1β at protein and mRNA levels, and down-regulated the phosphorylation of MAPKs （ERK1/2, JNK and p38）. These suppressing effects of 17β-E2 on Hcy-induced changes were reversed by pretreatment with PI3-K inhibitor Wortmannin. The results indicate that 17β-estradiol may attenu- ate Hcy-induced oxidative stress, inflammatory response and up-regulation of MAPKs in Raw 264.7 cells via PI3-K/Akt signal transduction pathway.

关 键 词：17Β-ESTRADIOL HOMOCYSTEINE reactive oxygen species MAPKS PI3-K/AKT 

分 类 号：Q255[生物学—细胞生物学] Q26