Analysis of polymorphisms in the 3' untranslated region of the LDL receptor gene and their effect on plasma cholesterol levels and drug response

Int J Mol Med. 2008 Mar;21(3):345-53.

Abstract

The proximal section of the 3' untranslated region (3'UTR) of LDL receptor (LDLR) mRNA contains important regulatory sequences that control the messenger stability and mediate the cholesterol-lowering drug berberine (BBR)-induced increase in LDLR mRNA half-life. In the present study, we examined whether single nucleotide polymorphisms (SNPs) within this region cause a predisposition to the development of coronary heart disease (CHD) and whether they affect the response to BBR treatment. Genomic DNAs were isolated from peripheral blood of a Chinese cohort of 103 normolipidemic subjects and 94 hyperlipidemic CHD patients. The 1.1-kb proximal fragment of LDLR mRNA 3'UTR was PCR-amplified and sequenced. Six SNPs were detected within this region. Among them, the presence of SNP1 and SNP6 in both study groups showed complete association (r2=1). The frequency of individual SNPs and genotypes did not differ between CHD patients and normolipidemic individuals. Allelic variations did not correlate with total and LDL-cholesterol levels. To examine the effects of genetic variations in 3'UTR on BBR treatment, entire 2.5-kb regions of 3'UTR from three common SNP haplotypes were cloned into a luciferase reporter and the reporter constructs were transfected into HepG2 cells. The expression of reporter genes carrying different haplotypes of LDLR 3'UTR was increased to a similar extent upon BBR treatment. Taken together, these findings suggest that the 3'UTR LDLR polymorphisms commonly found in the Chinese population do not cause a predisposition to the development of CHD, nor do they affect the plasma lipid levels or the cholesterol-lowering effect of BBR.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • 3' Untranslated Regions / genetics*
  • Asian People / genetics
  • Base Sequence
  • Berberine / pharmacology*
  • Cell Line, Tumor
  • China
  • Cholesterol / blood*
  • Cohort Studies
  • DNA Mutational Analysis
  • Female
  • Gene Expression Regulation / drug effects
  • Gene Frequency
  • Genes, Reporter
  • Genetic Predisposition to Disease
  • Haplotypes
  • Humans
  • Linkage Disequilibrium / genetics
  • Lipids / blood
  • Male
  • Middle Aged
  • Molecular Sequence Data
  • Polymorphism, Single Nucleotide / genetics*
  • RNA Stability
  • Receptors, LDL / genetics*

Substances

  • 3' Untranslated Regions
  • Lipids
  • Receptors, LDL
  • Berberine
  • Cholesterol