Identification of genes affecting apolipoprotein B secretion following siRNA-mediated gene knockdown in primary human hepatocytes

ObjectiveGenome-wide association studies (GWAS) are useful in studying the complex pathways underlying diseases such as atherosclerosis; however, additional testing is often necessary to identify the disease causal genes linked to GWAS loci. We used siRNA-mediated gene knockdown in primary human hepatocytes (PHuH) to identify potential GWAS causal genes affecting the hepatic secretion of apolipoprotein B (ApoB), ApoA1, and proprotein convertase subtilisin/kexin type 9.Materials and methodsCandidate causal genes within GWAS loci affecting human plasma levels of total cholesterol, LDL-cholesterol, HDL-cholesterol, and triglycerides were identified from the literature; 191 genes were selected from 74 loci. A functional siRNA screen was performed using PHuH.ResultsFour genes: poly (ADP-ribose) polymerases member 10, haptoglobin, fucosyltransferase 1, and lysophosphatidic acid receptor 2 were identified and confirmed. Knocking down these genes reduced cell-associated and secreted ApoB levels.ConclusionModification of these four genes may affect plasma lipids through modulation of ApoB secretion.

► siRNA-mediated gene knockdown in primary human hepatocytes was used to identify potential causal genes affecting lipid traits. ► Approximately 100 GWAS loci significantly affecting human plasma lipid levels were identified. ► A total of 191 genes from 74 loci were selected and subjected to siRNA-mediated gene knockdown. ► Four genes (PARP10, HP, FUT1, and LPAR2) were identified and verified as affecting ApoB secretion.