MicroRNAs 185, 96, and 223 repress selective high-density lipoprotein cholesterol uptake through posttranscriptional inhibition

Mol Cell Biol. 2013 May;33(10):1956-64. doi: 10.1128/MCB.01580-12. Epub 2013 Mar 4.

Abstract

Hepatic scavenger receptor class B type I (SR-BI) plays an important role in selective high-density lipoprotein cholesterol (HDL-C) uptake, which is a pivotal step of reverse cholesterol transport. In this study, the potential involvement of microRNAs (miRNAs) in posttranscriptional regulation of hepatic SR-BI and selective HDL-C uptake was investigated. The level of SR-BI expression was repressed by miRNA 185 (miR-185), miR-96, and miR-223, while the uptake of 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI)-HDL was decreased by 31.9% (P < 0.001), 23.9% (P < 0.05), and 15.4% (P < 0.05), respectively, in HepG2 cells. The inhibition of these miRNAs by their anti-miRNAs had opposite effects in these hepatic cells. The critical effect of miR-185 was further validated by the loss of regulation in constructs with mutated miR-185 target sites. In addition, these miRNAs directly targeted the 3' untranslated region (UTR) of SR-BI with a coordinated effect. Interestingly, the decrease of miR-96 and miR-185 coincided with the increase of SR-BI in the livers of ApoE KO mice on a high-fat diet. These data suggest that miR-185, miR-96, and miR-223 may repress selective HDL-C uptake through the inhibition of SR-BI in human hepatic cells, implying a novel mode of regulation of hepatic SR-BI and an important role of miRNAs in modulating cholesterol metabolism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3' Untranslated Regions
  • Animals
  • Apolipoproteins E / deficiency
  • Apolipoproteins E / genetics
  • Base Sequence
  • Cholesterol / blood
  • Cholesterol, HDL / metabolism*
  • Gene Expression
  • Genes, Reporter
  • Hep G2 Cells
  • Humans
  • Liver / metabolism
  • Luciferases, Renilla / biosynthesis
  • Luciferases, Renilla / genetics
  • Macrophages / metabolism
  • Male
  • Mice
  • Mice, Knockout
  • MicroRNAs / metabolism*
  • MicroRNAs / physiology
  • RNA Interference*
  • Scavenger Receptors, Class B / genetics
  • Scavenger Receptors, Class B / metabolism

Substances

  • 3' Untranslated Regions
  • Apolipoproteins E
  • Cholesterol, HDL
  • MIRN185 microRNA, human
  • MIRN223 microRNA, human
  • MIRN96 microRNA, human
  • MicroRNAs
  • SCARB1 protein, human
  • Scavenger Receptors, Class B
  • Cholesterol
  • Luciferases, Renilla