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

J Biomol Screen. 2007 Mar;12(2):211-9. doi: 10.1177/1087057106297568. Epub 2007 Jan 26.

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.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 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
  • Isoflavones / pharmacology*
  • Lipoproteins, HDL / genetics
  • Lipoproteins, HDL / metabolism*
  • Liver Neoplasms / pathology
  • Luciferases / metabolism
  • PPAR gamma / agonists
  • Receptors, Lipoprotein / genetics
  • Receptors, Lipoprotein / metabolism*
  • Recombinant Fusion Proteins / metabolism
  • Rosiglitazone
  • Scavenger Receptors, Class B / genetics
  • Scavenger Receptors, Class B / metabolism*
  • Thiazolidinediones / pharmacology
  • Transcription, Genetic / drug effects
  • Up-Regulation*

Substances

  • 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