Amyloid Beta Peptides Affect Pregnenolone and Pregnenolone Sulfate Levels in PC-12 and SH-SY5Y Cells Depending on Cholesterol.

Increased amyloid beta (AB) peptide concentration is one of the initiating factors in the neurodegeneration process. It has been suggested that cholesterol induces the synthesis of AB peptide from amyloid precursor protein or facilitates the formation of amyloid plaque by lowering the aggregation threshold of the peptide. It is also shown that AB peptides may affect cholesterol metabolism and the synthesis of steroid hormones such as progesterone and estradiol.