Opposing effects of oestradiol and progesterone on intracellular pathways and activation processes in the oxidative stress induced activation of cultured rat hepatic stellate cells. Issue 12 (13th July 2005)

• Record Type: Journal Article
• Authors: Itagaki, T; Shimizu, I; Cheng, X; Yuan, Y; Oshio, A; Tamaki, K; Fukuno, H; Honda, H; Okamura, Y; Ito, S
• Is Part Of: Gut. Volume 54:Issue 12(2005)
• Page Start: 1782
• Page End: 1789
• Publication Date: 2005-07-13
• Subjects: αSMA, α smooth muscle actin -- AP-1, activator protein-1 -- BrdU, bromodeoxyuridine -- CuZn-SOD, zinc dependent SOD -- DMEM, Dulbecco's modified Eagle's medium -- ELISA, enzyme linked immunosorbent assay -- EMSA, electrophoretic mobility shift assay -- ERK, extracellular signal regulated kinase -- FBS, fetal bovine serum -- H2DCF-DA, 2′, 7′-dichlorofluorescein diacetate -- HSC, hepatic stellate cell -- JNK, c-Jun N-terminal kinase/stress activated protein kinase -- MAPK, mitogen activated βprotein kinase -- MDA, malondialdehyde -- NF-κB, nuclear factor κB -- p38, p38 MAPK -- p-p38, phosphorylated p38 -- PBS, phosphate buffered saline -- PDGF, platelet derived growth factor -- p-ERK, phosphorylated ERK -- p-JNK, phosphorylated JNK -- RT-PCR, reverse transcription-polymerase chain reaction -- ROS, reactive oxygen species -- SDS, sodium dodecyl sulfate -- SOD, superoxide dismutase -- TGF-β1, transforming growth factor-β1; oestradiol -- progesterone -- hepatic stellate cells -- ROS -- TGF-β; Gastroenterology -- Periodicals; 616.33
• DOI: 10.1136/gut.2004.053728
• Languages: English
• ISSNs: 0017-5749

Abstract

Abstract : Background: Oxidative stress, including the generation of reactive oxygen species (ROS), is involved in hepatofibrogenesis. The authors' previous studies have shown that oestradiol suppresses hepatic fibrosis in animal models and attenuates the activation of cultured rat hepatic stellate cells (HSCs), which possess oestrogen receptor subtype β and are also activated by ROS. Aims: To define the mechanisms by which female sex hormones play an antifibrogenic role in activated HSCs, the effects of oestradiol and progesterone on ROS generation processes and intracellular pathways, leading to the activation of HSCs undergoing oxidative stress, was examined. Methods: HSCs, isolated from rats, were cultured for 7 days with oestradiol or progesterone for 24 hours as pretreatment, and oxidative stress was then induced by exposure to low doses of hydrogen peroxide for another 24 hours. Results: Oestradiol inhibited ROS generation and antioxidant enzyme loss via the suppression of NADH/NADPH oxidase activity, and attenuated hydrogen peroxide induced transforming growth factor-β1 (TGF-β1) expression, HSC proliferation and transformation, and the activation of mitogen activated protein kinase (MAPK) pathways and transcription factors. Progesterone exerted a stimulatory effect through the progesterone receptor on the induction of ROS generation processes and intracellular pathways, resulting in TGF-β1 expression and HSC activation, and fibrogenic effects were inhibited by oestradiol. Conclusion: These findings show for the first time that oestradiol inhibits the activation of transcription factors by suppressing ROS generation processes and the MAPK pathways, and inactivates the downstream transcription processes involved in TGF-β1 expression and HSC activation, whereas progesterone acts in opposition to the favourable effects of oestradiol and its effects are blocked by oestradiol.