Figure 1. GPR146 Regulates Plasma Cholesterol Levels in both Human and Mouse.
(A) Reginal (7p22 locus) association of GWAS variants with plasma cholesterol levels shows that common SNP rs1997243 (purple diamond) and GPR146 p.Gly11Glu (red circle) are significantly associated with plasma TC levels in humans.
(B) eQTL studies using 2,116 human blood samples revealed a highly significant dose-dependent relation between the rs1997243 G-allele and GPR146 expression (n=1428 for A/A, n=627 for A/G and n=61 for G/G).
(C) Schematic diagram showing generation of Gpr146 whole-body knockout (Gpr146−/−) and floxed mouse models (Gpr146fl/fl) using CRISPR/Cas9 system.
(D) Gpr146 mRNA levels in epididymal white adipose tissue (eWAT), inguinal white adipose tissue (ingWAT), interscapular brown adipose tissue (iBAT), liver, skeletal muscle tibialis anterior (TA), quadriceps (Quad), heart, kidney and intestine, of 8-weeks old Gpr146 wild type (+/+) and knockout (−/−) male mice (n=3 mice per group).
(E and H) Plasma total cholesterol (TC) levels of 16-hour fasted male (E) and female (H) Gpr146 wild-type (+/+) mice and knockout (−/−) littermates fed chow at different ages indicated (n= 13–18 mice per group, by Student’s t-test).
(F and I) Pooled plasma from male (F) and female (I) mice was subjected to Fast Protein Liquid Chromatography (FPLC) analysis, and cholesterol was measured in each of the eluted fractions (pooled samples of n=13–18 mice per group).
(G and J) Area under curve (AUC) was used to calculate the levels of VLDL-C (fractions 7 to 13), IDL/LDL-C (fraction 13 to 29) and HDL-C (fraction 29 to 49) in FPLC plots (F and I).
* p< 0.05, ** p< 0.01; bars in E and H indicate mean ± s.d.; bars in D indicate mean± s.e.m.