Researchers have reported in the February issue of PNAS that understanding and treating cholesterol-related illnesses in humans may now be easier with the discovery of a receptor in the cells of mice that protects them from toxins. Researchers discovered the receptor during a study of cerebrotendinous xanthomatosis (CTX), a rare and often fatal disorder caused by excessive cholesterol metabolites. They said that Pregnane X receptor (PXR) is present in humans but does not recognise or eliminate all toxins as effectively as it does in our diminutive counterparts. In mice, PXR senses the presence of excess cholesterol by-products and immediately activates special pathways that remove these toxins. The main problem with the PXR receptors in humans is that they are not activated by the metabolites to trigger an effective response and clear away the cholesterol.
The study suggested that harnessing PXR could benefit people with high cholesterol worldwide, apart from those patients suffering from CTX. They further added that CTX and other cholesterol-related illnesses could be treated or possibly even prevented with existing drugs like rifampicin and St. John's Wort, which do activate the PXR receptor in humans.