BACKGROUND Sitosterolemia is a recessively inherited disorder that results from mutations in either ABCG5 or G8 proteins, with hyperabsorption of dietary sterols and decreased hepatic excretion of plant sterols and cholesterol. As a consequence of markedly elevated plasma and tissue sitosterol and campesterol levels, premature atherosclerosis develops. METHODS AND RESULTS In this multicenter,...

In spite of the universal occurrence of steroids in plants, the role of these materials remains quite unknown. That steroids possess physiological activity for the higher plant was in fact demonstrated only after the discovery of estrogenic principles in plants in 1926-1927 by LOEWE and SPOHR (22), DOHRN et al. (12), and LOEWE et al. (20, 21). The status of our knowledge of the influence of the...

The individual roles of hepatic versus intestinal ABCG5 and ABCG8 in sterol transport have not yet been investigated. To determine the specific contribution of liver ABCG5/G8 to sterol transport and atherosclerosis, we generated transgenic mice that overexpress human ABCG5 and ABCG8 in the liver but not intestine (liver G5/G8-Tg) in three different genetic backgrounds: C57Bl/6, apoE-KO, and low...

BACKGROUND Evidence is increasing that plant sterols and stanols not only lower fasting serum low-density lipoprotein concentrations, but also those of triglycerides (TG). Insight into effects of these components on postprandial TG metabolism, an emerging risk factor for cardiovascular disease, is missing. OBJECTIVE Our objective was to examine the 8-hour postprandial response after consuming...

Whole body sterol metabolism in insects has seldom been studied. We were able to design an appropriate study at a butterfly farm in Belize. We collected six larvas of butterfly (Morpho peleides), their food (leaves of Pterocarpus bayessii), and their excretions. In addition, six adult butterflies were collected. The sterols of the diet, the larva, and adult butterfly were analyzed by gas-liquid...

BACKGROUND The relationship of cholesterol homeostasis and carotid intima-media thickness (cIMT) is unknown. To address this, we assessed markers of cholesterol homeostasis (serum plant sterols and cholesterol precursor concentrations as surrogate measures of cholesterol absorption and synthesis, respectively) and cIMT in a middle-aged, statin-naive population. METHODS In this prospective stu...

BACKGROUND Plant sterols are bioactive compounds, found in all vegetable foods, which inhibit cholesterol absorption. Little is known about the effect of habitual natural dietary intake of plant sterols. OBJECTIVE We investigated the relation between plant sterol density (in mg/MJ) and serum concentrations of cholesterol in men and women in northern Sweden. DESIGN The analysis included 37 1...

Sterols play vital roles in plant growth and development, as components of membranes and as precursors to steroid hormones. Analysis of Arabidopsis mutants indicates that sterol composition is crucial for cellulose biosynthesis. Sterols are widespread in the plasma membrane (PM), suggesting a possible link between sterols and the multimeric cellulose synthase complex. In one possible scenario, ...

Sterols play multi-faceted roles in all eukaryotes. In plants, there are mounting evidences pointing to sterols, other than BRs, can act as signaling molecules. The Arabidopsis dry2/sqe1-5 mutant has multiple developmental defects caused by a point mutation in the SQE1 gene that generates a hypomorphic allele. SQE1 encodes a squalene epoxidase, which converts squalene into 2,3-oxidosqualene the...

The molecular genetic, and biochemical analysis of sterol-deficient mutants in Arabidopsis strongly suggests an essential role for sterols in regulating multiple events in plant development, independent of their conversion to brassinosteroids (BRs). Embryogenesis, cell elongation, vascular differentiation, and hormone signaling all are affected by the alteration of sterol levels, but the molecu...