The SCARB1 rs5888 SNP and serum lipid levels in the Guangxi Mulao and Han populations

Abstract

Background: The associations of scavenger receptor class B type 1 (SCARB1) rs5888 single nucleotide polymorphism (SNP) and serum lipid levels are inconsistant among diverse ethnic populations. The present study was undertaken to detect the association of rs5888 SNP and serum lipid levels in the Guangxi Mulao and Han populations.

Methods: Genotypes of the SCARB1 rs5888 SNP in 801 subjects of Mulao and 807 subjects of Han Chinese were determined by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing.

Results: Serum apolipoprotein (Apo) B levels and the T allelic frequency were higher in Mulao than in Han. Serum high-density lipoprotein cholesterol (HDL-C) levels in Mulao were different among the genotypes, the subjects with TT genotype had lower HDL-C levels than the subjects with CC or CT genotype in female (P < 0.05). For the Han population, serum triglyceride (TG), HDL-C, ApoAI, ApoB levels and the ratio of ApoAI to ApoB in males were different among the genotypes, the T allele carriers had lower serum HDL-C, ApoAI levels and ApoAI/ApoB ratio and higher serum ApoB levels than the T allele noncarriers (P < 0.05 for all), the subjects with TT genotype had higher serum TG levels than the subjects with CC or CT genotype. Serum HDL-C levels in Mulao females and serum HDL-C, ApoAI, ApoB levels and the ApoAI/ApoB ratio in Han males were correlated with genotypes by the multiple linear regression analysis. Serum lipid parameters were also influenced by genotype-environmental interactions in Han but not in Mulao populations.

Conclusions: These results suggest that the rs5888 SNP is associated with serum HDL-C levels in Mulao females, and TG, HDL-C, ApoAI, ApoB levels and the ApoAI/ApoB ratio in Han males. The differences in serum ApoB levels between the two ethnic groups might partially attribute to different SCARB1 genotype-environmental interactions.

Keywords: apolipoproteins; lipids; scavenger receptor class B type 1 gene; single nucleotide polymorphism.

Figure 1

Genotyping of rs5888 SNP in the SCARB1 gene. Lane M, 50 bp marker ladder; lanes 1 and 2, PCR products (218 bp); lanes 3 and 4, TT genotype (218 bp); lanes 7 and 8, CT genotype (218-, 187- and 31-bp); and lanes 5, 6, 9 and 10, CC genotype (187- and 31-bp). The 31 bp fragment was invisible in the gel owing to its fast migration speed.

Figure 2

A part of the nucleotide sequence of rs5888 SNP in the SCARB1 gene. (A) CC genotype; (B) CT genotype; (C) TT genotype.