Study identifies gene that helps regulate cholesterol levels

The work implicates a gene that normally reins in cholesterol production in the liver when dietary cholesterol intake is high.The study features in the journal Cell Metabolism.The work drew upon genome-wide association studies, which scour huge databases of genome sequences for correlations between particular genetic variations and specific characteristics, such as certain health conditions.However, while these studies can narrow down the search, they cannot identify individual genes that are responsible for disease.“We can do these very large studies in humans of 500,000 people, and we can identify regions of the genome that are associated with, say, differences in blood cholesterol,” says Prof. The researchers first studied mouse livers in the lab, identifying a network of 112 genes that are involved in synthesizing cholesterol.They then searched human genome databases to find which of these 112 genes overlap with DNA sequences that researchers have linked to high cholesterol levels in people.This process helped them identify 54 genes, 25 of which stood out because their role in cholesterol or lipid metabolism was previously unknown.A further round of tests narrowed the search still further to a gene called Sestrin1.The researchers went on to discover that Sestrin1 might shut down cholesterol synthesis in the liver when adequate amounts of cholesterol are available from the diet.