Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2007 May;27(5):1108-14.
doi: 10.1161/ATVBAHA.106.138545. Epub 2007 Feb 15.

Oxysterol binding protein induces upregulation of SREBP-1c and enhances hepatic lipogenesis

Daoguang Yan  1 , Markku Lehto, Laura Rasilainen, Jari Metso, Christian Ehnholm, Seppo Ylä-Herttuala, Matti Jauhiainen, Vesa M Olkkonen
Affiliations

Oxysterol binding protein induces upregulation of SREBP-1c and enhances hepatic lipogenesis

Daoguang Yan et al. Arterioscler Thromb Vasc Biol. 2007 May.

Abstract

Background: Oxysterol binding protein (OSBP) has previously been implicated as a sterol sensor that regulates sphingomyelin synthesis and the activity of extracellular signal-regulated kinases (ERK).

Methods and results: We determined the effects of adenovirus-mediated hepatic overexpression of OSBP and its homologues ORP1L and ORP3 on mouse serum lipids. Whereas ORP1L and ORP3 had no effect on serum lipids, OSBP induced a marked increase of VLDL triglycerides (TG). Also, the liver tissue TG were elevated in the AdOSBP-injected mice, and their TG secretion rate was increased by 70%. The messenger RNAs for enzymes of fatty acid synthesis and their transcriptional regulator, SREBP-1c, as well as the Insig-1 mRNA, were upregulated two-fold in the OSBP-expressing livers. No change occurred in the messages of liver X receptor target genes ABCA1, ABCG5, and CYP7A1, and the Insig-2a mRNA was reduced. The phosphorylation of ERK was decreased in AdOSBP-infected liver and cultured hepatocytes. Importantly, silencing of OSBP in hepatocytes suppressed the induction of SREBP1-c by insulin and resulted in a reduction of TG synthesis.

Conclusion: Our results demonstrate that OSBP regulates hepatic TG metabolism and suggest the involvement of OSBP in the insulin signaling pathways that control hepatic lipogenesis.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

Publication types

MeSH terms

LinkOut - more resources