Genetic polymorphism in milk fat globule-EGF factor 8 (MFG-E8) is associated with systemic lupus erythematosus in human

Lupus. 2009 Jul;18(8):676-81. doi: 10.1177/0961203309103027.

Abstract

Milk fat globule-EGF factor 8 (MFG-E8) is a molecule implicated in phagocytic clearance of apoptotic cells by bridging between macrophages and apoptotic cells. Defects in MFG-E8 cause lupus-like disease in murine models. The aim of our study is to determine whether genetic variation in MFG-E8 predisposes human to systemic lupus erythematosus (SLE). A case-control study of MFG-E8 genetic polymorphism was performed on 147 SLE patients and 146 non-lupus control subjects. Single nucleotide polymorphisms (SNPs) in the coding sequence of human MFG-E8 gene were investigated. SNPs on MFG-E8 residues 3 (3(Arg or Ser)) and 76 (76(Leu or Met)) did not show genetic linkage. Genetic polymorphism on MFG-E8 residue 76 correlated significantly to SLE. The MFG-E8-76(Met) allele predisposed subjects to SLE in a recessive mode (odds ratio: 2.1, P = 0.020), while carriage of MFG-E8-76(Leu) were negatively associated with SLE. The MFG-E8 genotypic combinations with 3(Ser) and 76(Leu) showed the most pronounced protective effect on SLE when compared to the most predisposing genotype 3(Arg/Arg)-76(Met/Met) (OR: 0.29, P = 0.007). According to our result, MFG-E8 is associated with SLE predisposition in Taiwanese. Our study implicates that the impairment of phagocytic clearance of apoptotic cells through phosphotidylserine-dependent MFG-E8 system may lead to the development of human SLE.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Animals
  • Antigens, Surface / genetics*
  • Base Sequence
  • Case-Control Studies
  • DNA Mutational Analysis
  • Female
  • Genetic Predisposition to Disease*
  • Genotype
  • Humans
  • Lupus Erythematosus, Systemic / genetics*
  • Male
  • Middle Aged
  • Milk Proteins / genetics*
  • Molecular Sequence Data
  • Phagocytes / metabolism
  • Polymorphism, Genetic*
  • Young Adult

Substances

  • Antigens, Surface
  • MFGE8 protein, human
  • Milk Proteins