Peroxisome proliferator-activated receptor-alpha (PPARα) is a nuclear receptor that regulates the expression of genes related to cellular lipid uptake and oxidation. Thus, PPARα agonists may be important in the treatment of hypertriglyceridemia and hepatic steatosis. In this study, we demonstrated that catalposide is a novel natural PPARα agonist, identified from reporter gene assay-based activity screening with approximately 900 natural plant and seaweed extracts. Results of time-resolved fluorescence resonance energy transfer analyses suggested that the compound interacted directly with the ligand-binding domain of PPARα. Cultured hepatocytes stimulated with catalposide exhibited significantly reduced cellular triglyceride concentrations, by 21%, while cellular uptake of fatty acids was increased, by 70% (. P<0.05). Quantitative PCR analysis revealed that the increase in cellular fatty acid uptake was due to upregulation of fatty acid transporter protein-4 (+19% vs. the control) in cells stimulated with catalposide. Additionally, expression of genes related to fatty acid oxidation and high-density lipoprotein metabolism were upregulated, while that of genes related to fatty acid synthesis were suppressed. In conclusion, catalposide is hypolipidemic by activation of PPARα via a ligand-mediated mechanism that modulates the expression of in lipid metabolism genes in hepatocytes.
|Number of pages||5|
|Journal||Biochemical and biophysical research communications|
|Publication status||Published - 2012 Jun 15|
Bibliographical noteFunding Information:
This study was supported by the Korean Forest Service (Forest Science & Technology Project No. S120909L130110), the Technology Development Program for Fisheries of the Ministry for Food, Agriculture, Forestry and Fisheries, Republic of Korea (iPET, F20926409H220000110), and the Basic Science Research Program of the National Research Foundation of Korea (NRF), funded by the Ministry of Education, Science and Technology (20100028180). The SPR instrument was provided by the Korea Basic Science Institute. We thank Hea-Won Kim for technical assistance.
- Lipid metabolism
- Peroxisome proliferator receptor
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology