Identification of novel human high-density lipoprotein receptor Up-regulators using a cell-based high-throughput screening assay.

Abstract

Scavenger receptor class B type I (SR-BI) is the high-affinity high-density lipoprotein (HDL) receptor, and CLA-1 is the human homologue of the murine SR-BI. CLA-1/SR-BI receptor has been suggested as a new preventative and/or therapeutic target for atherosclerosis due to its pivotal role in overall HDL cholesterol (HDL-C) metabolism and its antiatherogenic activity in vivo. To search for active compounds that can increase CLA-1 transcription, a novel cell-based assay was developed for application in high-throughput screening (HTS). Human hepatoma HepG2 cells were transfected with a CLA-1-promoter-luciferase reporter gene construct, and the stable transfected cell line was selected and named CLAp-LUC HepG2. With rosiglitazone as a positive control, this stable cell line was used to establish a specific CLA-1 gene expression assay in a 96-well microplate format. The evaluating parameter Z' value of 0.64 showed that this cell-based HTS assay was robust and reliable. Screening of 6000 microbial secondary metabolite crude extracts identified 8 positive strains. Between 2 identified CLA-1 up-regulators produced by actinomycete strain 04-4776, 4776B may stimulate not only the expression of CLA-1 on the transcriptional and translational levels but also the activity of CLA-1 to uptake the HDL-C in HepG2 cells. The active compounds originated from this HTS assay may be developed to drug candidates or lead compounds for new antiatherosclerosis agents.

• Authors: Yuan Yang, Zhongbing Zhang, Wei Jiang, Lei Gao, Guiyu Zhao, Zhihui Zheng, Min Wang, Shuyi Si, Bin Hong
• Journal: Journal of biomolecular screening (J Biomol Screen) Vol. 12 Issue 2 Pg. 211-9 (Mar 2007) ISSN: 1087-0571 [Print] United States
• PMID: 17259591 (Publication Type: Evaluation Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Carbocyanines
• Fluorescent Dyes
• Isoflavones
• Lipoproteins, HDL
• PPAR gamma
• Receptors, Lipoprotein
• Recombinant Fusion Proteins
• SCARB1 protein, human
• Scavenger Receptors, Class B
• Thiazolidinediones
• high density lipoprotein receptors
• Rosiglitazone
• Hydroxyl Radical
• 3,3'-dioctadecylindocarbocyanine
• 4'-methoxy-3',5,7-trihydroxyisoflavone
• Luciferases

Topics

• Actinomycetaceae (metabolism)
• Biological Assay (methods)
• Carbocyanines
• Carcinoma, Hepatocellular (pathology)
• Cell Line, Tumor
• Dose-Response Relationship, Drug
• Drug Evaluation, Preclinical
• Fermentation
• Fluorescent Dyes
• Gene Expression Regulation (drug effects)
• Genes, Reporter
• Humans
• Hydroxyl Radical (chemistry)
• Isoflavones (isolation & purification, pharmacology)
• Lipoproteins, HDL (genetics, metabolism)
• Liver Neoplasms (pathology)
• Luciferases (metabolism)
• PPAR gamma (agonists)
• Receptors, Lipoprotein (genetics, metabolism)
• Recombinant Fusion Proteins (metabolism)
• Rosiglitazone
• Scavenger Receptors, Class B (genetics, metabolism)
• Thiazolidinediones (pharmacology)
• Transcription, Genetic (drug effects)
• Up-Regulation