CD36 is involved in lycopene and lutein uptake by adipocytes and adipose tissue cultures
International audience; Scope: Carotenoids are mainly stored in adipose tissue. However, nothing is known regarding the uptake of carotenoids by adipocytes. Thus, our study explored the mechanism by which lycopene and lutein, two major human plasma carotenoids, are transported. Methods and results: CD36 was a putative candidate for this uptake, 3T3-L1 cells were treated with sulfosuccinimidyl oleate, a CD36-specific inhibitor. sulfosuccinimidyl oleate-treated cells showed a significant decrease in both lycopene and lutein uptake as compared to control cells. Their uptake was also decreased by partial inhibition of CD36 expression using siRNA, whereas the overexpression of CD36 in Cos-1 cell…
Sterol Regulatory Element-binding Protein-1c Is Responsible for Cholesterol Regulation of Ileal Bile Acid-binding Protein Gene in Vivo
Ileal bile acid-binding protein (I-BABP) is a cytosolic protein that binds bile acid (BA) specifically. In the ileum, it is thought to be implied in their enterohepatic circulation. Because the fecal excretion of BA represents the main physiological way of elimination for cholesterol (CS), the I-BABP gene could have a major function in CS homeostasis. Therefore, the I-BABP gene expression might be controlled by CS. I-BABP mRNA levels were significatively increased when the human enterocyte-like CaCo-2 cells were CS-deprived and repressed when CS were added to the medium. A highly conserved sterol regularory element-like sequence (SRE) and a putative GC box were found in human I-BABP gene pr…