CD36 and SR-BI are involved in cellular uptake of provitamin A carotenoids by Caco-2 and HEK cells, and some of their genetic variants are associated with plasma concentrations of these micronutrients in humans

J Nutr. 2013 Apr;143(4):448-56. doi: 10.3945/jn.112.172734. Epub 2013 Feb 20.

Abstract

Scavenger receptor class B type I (SR-BI) and cluster determinant 36 (CD36) have been involved in cellular uptake of some provitamin A carotenoids. However, data are incomplete (e.g., there are no data on α-carotene), and it is not known whether genetic variants in their encoding genes can affect provitamin A carotenoid status. The objectives were 1) to assess the involvement of these scavenger receptors in cellular uptake of the main provitamin A carotenoids (i.e., β-carotene, α-carotene, and β-cryptoxanthin) as well as that of preformed vitamin A (i.e., retinol) and 2) to investigate the contribution of genetic variations in genes encoding these proteins to interindividual variations in plasma concentrations of provitamin A carotenoids. The involvement of SR-BI and CD36 in carotenoids and retinol cellular uptake was investigated in Caco-2 and human embryonic kidney (HEK) cell lines. The involvement of scavenger receptor class B type I (SCARB1) and CD36 genetic variants on plasma concentrations of provitamin A carotenoids was assessed by association studies in 3 independent populations. Cell experiments suggested the involvement of both proteins in cellular uptake of provitamin A carotenoids but not in that of retinol. Association studies showed that several plasma provitamin A carotenoid concentrations were significantly different (P < 0.0083) between participants who bore different genotypes at single nucleotide polymorphisms and haplotypes in CD36 and SCARB1. In conclusion, SR-BI and CD36 are involved in cellular uptake of provitamin A carotenoids, and genetic variations in their encoding genes may modulate plasma concentrations of provitamin A carotenoids at a population level.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • CD36 Antigens / genetics*
  • CD36 Antigens / physiology*
  • Caco-2 Cells
  • Carotenoids / blood*
  • Carotenoids / metabolism*
  • Cross-Sectional Studies
  • Cryptoxanthins
  • Female
  • Genetic Variation
  • Genotype
  • HEK293 Cells
  • Humans
  • Male
  • Polymorphism, Single Nucleotide / genetics
  • Scavenger Receptors, Class B / genetics*
  • Scavenger Receptors, Class B / physiology*
  • Sex Factors
  • Vitamin A / metabolism
  • Xanthophylls / blood
  • Xanthophylls / metabolism
  • beta Carotene / blood
  • beta Carotene / metabolism

Substances

  • CD36 Antigens
  • Cryptoxanthins
  • SCARB1 protein, human
  • Scavenger Receptors, Class B
  • Xanthophylls
  • beta Carotene
  • Vitamin A
  • Carotenoids
  • alpha-carotene