28-Homobrassinolide: a novel oxysterol transactivating LXR gene expression
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- 作者：R. Premalatha (1)
K. Srikumar (1)
D. Vijayalaksmi (2)
G. N. Kumar (1)
P. P. Mathur (1) (2) (3) - 关键词：28 ; Homobrassinolide (28 ; HB) ; Plant oxysterol ; 28 ; HB ; LXR interactions ; LXR ; α expression ; LXR ; β expression
- 刊名：Molecular Biology Reports
- 出版年：2014
- 出版时间：November 2014
- 年：2014
- 卷：41
- 期：11
- 页码：7447-7461
- 全文大小：3,013 KB
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文摘
Cholesterol is the template for steroid hormone biosynthesis. Cholesterol homeostasis is regulated by Cyt-P450 oxygenated cholesterols acting as ligands on LXR-α and LXR-β transcription factors that are now emerging as drug targets. Heterodimerization of LXRs with retinoic acid receptor is considered a prerequisite for target gene activation. Dietary plant oxysterol 28-homobrassinolide (28-HB) is a proven antihyperglycemic and a pro-steroidogenic agent in the rat. Whether 28-HB has a role in LXR gene expression was therefore investigated using oral gavage (15?days) of 28-HB (333?μg/kg b w) to normal and diabetic rat. PCR amplified LXR-α and β mRNA transcripts from treated rat liver and testis exhibited quantitative differences in their expression. Conformational differences in 28-HB docking to LXR-α and β binding domains were also noted through in silico studies, LXR-β adopting lesser specificity. We report that 28-HB transactivates LXR genes in the rat tissues.