GPR146 and Cholesterol Metabolism

Blood cholesterol balance is regulated by an interplay between the small intestine and the liver. Recently, a new protein (cholesin) was discovered, which is secreted by intestinal cells after dietary cholesterol intake. Cholesin travels to the liver and binds to the GPR146 receptor. This inhibits cholesterol production in the liver. Because plant sterols lower blood cholesterol levels by reducing cholesterol absorption in the intestine, we would like to understand the effects of plant sterols on GPR146. Our hypothesis is that the production of the GPR146 gene differs after adding plant sterols to a high-cholesterol diet compared to eating a high-cholesterol and low-cholesterol diet. The main objective of this study is to investigate whether the expression of the GPR146 gene in the blood of adults differs between three meals with different levels of cholesterol intake. The secondary objective of the study is to examine changes in the expression of cholesin, the LDL receptor (LDLR), and 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) genes in the blood after these meals. Furthermore, changes in the expression of these genes, all of which play an important role in cholesterol metabolism, will be examined in intestinal cells.