TITLE

Hydroxytyrosol stimulates lipolysis via A-kinase and extracellular signal-regulated kinase activation in 3T3-L1 adipocytes

AUTHOR(S)
Drira, Riadh; Sakamoto, Kazuichi
PUB. DATE
April 2014
SOURCE
European Journal of Nutrition;Apr2014, Vol. 53 Issue 3, p743
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Purpose: The principal function of the adipose tissue is the storage of energy in the form of triglyceride through the process of adipogenesis, as well as the provision of the stored energy through lipolysis. In the present study, we investigated the effect of hydroxytyrosol on lipolysis in 3T3-L1 adipocytes. Methods: 3T3-L1 adipocytes, used as in vitro model in this study, were treated with several concentration of hydroxytyrosol. Glycerol release was measured to identify the lipolytic rate activation. All factors activation and expression were carried out via Western blotting and qRT-PCR. Results: Our results showed that hydroxytyrosol, over a range of concentrations, attenuated triglyceride accumulation and stimulated glycerol release in fully differentiated adipocytes in a dose- and time-dependent manner. Moreover, hydroxytyrosol had no effect on adipocyte viability. To understand the mechanism underlying hydroxytyrosol-stimulated lipolysis, we used inhibitors of PKA, PKC, PKG, ERK1/2, and nitric oxide production. Pretreatment with a PKA inhibitor (Rp-cAMPs) and an ERK1/2 inhibitor (U0126) significantly attenuated hydroxytyrosol-stimulated lipolysis. In contrast, a PKC inhibitor (Calphostin C), 2 PKG inhibitors (KT 5823 and Rp-cGMPs), and a nitric oxide inhibitor (S-ethyl ITU) had no effect on hydroxytyrosol-stimulated lipolysis. Over the same range of concentrations, hydroxytyrosol downregulated the expression of adipose triglyceride lipase, hormone sensitive lipase (HSL), and adipogenesis-related transcription factors PPARγ and C/EBPα. In addition, hydroxytyrosol increased the phosphorylation rate of HSL at Ser563 and Ser660, as well as perilipin and ERK phosphorylation. Conclusion: Hydroxytyrosol induced lipolysis in 3T3-L1 adipocytes via the activation of PKA and ERK1/2 pathway.
ACCESSION #
95275547

 

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics