Scientists discover a compound that gets rid of excess cholesterol

Jan 27 2009

New research by scientists in the United States carried out in mice has revealed a compound that releases excessive cholesterol accumulated inside cells.

According to the team their discovery could lead to a therapy for Niemann-Pick type C disease (NP-C), an inherited disorder characterized by abnormally high cholesterol levels in all body organs.

Patients suffering from NP-C carry a genetic mutation which causes excessive amounts of cholesterol to accumulate in lysosomes - vesicles in cells - which leads to liver disease, dementia and neurodegeration.

The disease is usually diagnosed in children from age 3 to 15, most of whom die before age 20 with some never reaching age 10.

About 10 percent of cases have the disease in its adult form which manifests itself especially through neurological and psychological symptoms - few people diagnosed with NP-C ever reach the age of 40.

Professor John Dietschy, senior author of the study says the study has shown that very quickly after administration of the compound, the huge pool of cholesterol that has just been accumulating in the cells is suddenly released and metabolized normally.

The researchers at the University of Texas Southwestern Medical Center at Dallas, injected a single dose of CYCLO, a cholesterol-binding agent, into mice aged 7 days that had the NP-C mutation and shortly after receiving the injection, the mice began to process cholesterol just like the healthy mice - 49 days later the mice continued to demonstrate substantially lower tissue cholesterol levels than mice who did not receive the treatment and the mice also had improved liver function and less neurodegeneration.

Dr Dietschy, who has studied cholesterol metabolism for almost 50 years says the key is that they appear to have overcome the transport defect in the lysosome that is brought about by the genetic defect or mutation.

Dr Dietschy, a professor of internal medicine at the University of Texas Southwestern, warns that the findings do not represent a cure for NP-C as it is not yet understood what is happening at the molecular level even though it is clear that CYCLO somehow overcomes the genetic defect that causes individuals to accumulate cholesterol.

Dr Dietschy says the next stage will be to determine how much CYCLO concentration is needed to trigger the release of cholesterol, how much CYCLO can lengthen the life span of animals and also how long the drug's effects last.

The study is published in the Proceedings of the National Academy of Sciences.