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

Abstract

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 osteoporosis. 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 mechanisms and relevant signal transduction pathways underlying the action of Hcy remain unclear. In this study, we investigated the effects of 17β-estradiol (17β-E 2 ) 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 fluorospectrophotometry. The proinflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin (IL)-1β were analyzed by double-immunofluorescence labeling and reverse transcriptase polymerase chain reaction 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-E 2 's effect on Raw 264.7 cells. 17β-E 2 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-E 2 on Hcy-induced changes were reversed by pretreatment with PI3-K inhibitor Wortmannin. The results indicate that 17β-estradiol may attenuate Hcy-induced oxidative stress, inflammatory response and up-regulation of MAPKs in Raw 264.7 cells via PI3-K/Akt signal transduction pathway.

Hydrogen sulfide attenuates homocysteine‐induced osteoblast dysfunction by inhibiting mitochondrial toxicity

“…HHcy Zhang et al, 2015). However, the major proposed molecular and cellular mechanisms underlying the mitotoxicity and osteoblast dysfunction under Hcy are incompletely understood.…”

The Janus Face of Stress on Reproduction: From Health to Disease

“…We have to add, however, that ovarian steroid might have protective role by upregulating the expression of antioxidants [ 36 ]. Indeed, many preclinical reports indicated an enhancement in OS after ovariectomy [ 37 ] and in postmenopausal women estradiol therapy might decrease the ROS production [ 38 ].…”

MicroRNA‐217 suppresses homocysteine‐induced proliferation and migration of vascular smooth muscle cells via N‐methyl‐D‐aspartic acid receptor inhibition

“…Interestingly, our results show that ROS generation is also decreased at 48 hours after homocysteine treatment alone, which might suggest other mechanisms are involved in regulating ROS levels. 31 In summary, the present study pointed out that miR-217 might target NMDAR expression and loosen CREB-PGC-1α signalling in homocysteine-conditioned VSMCs, impeding cell proliferation and migration. The study might provide a novel target for future drug development in combating atherosclerosis.…”

“…Notably, PGC‐1α reduced NOX1 expression and repressed ROS generation in VSMCs after homocysteine exposure. Interestingly, our results show that ROS generation is also decreased at 48 hours after homocysteine treatment alone, which might suggest other mechanisms are involved in regulating ROS levels …”