La Jolla, CA Mouse mammary glands deficient in PPAR, a nuclear receptor that regulates the storage of fat, produce toxic milk that causes inflammation and baldness in suckling pups, report scientists at the Salk Institute for Biological Studies.
We were quite surprised by the unexpected quality control mechanism that ensures the quality of breast milk, says Ronald M. Evans, Ph.D., professor in the Salk Institutes Gene Expression Laboratory and a Howard Hughes Medical Investigator. Our finding explains why breast milk is always clean and healthful, even when theres a lot of inflammation going on in the mothers body, he adds.
The Salk research team led by Evans published their findings in the August issue of the journal Genes & Development. They hope that a better understanding of PPAR could help explain the role lipids and inflammation play in hair loss and other skin disorders and facilitate the development of new treatments for these diseases.
PPAR acts as a genetic switch, sensitizing the body to insulin and lowering levels of circulating glucose. In fact PPAR drugs, including Actos and Avandia, belong to the newest generation of anti-diabetic medications. Naturally occurring mutations in PPAR lead to obesity and insulin resistance associated with type 2 diabetes.
Unexpectedly, postdoctoral researcher and first author Yihong Wan, Ph.D., observed that mice lacking PPAR in endothelial cells had trouble rearing their newborns. Although the mothers seemed perfectly normal, the nursing offspring soon stopped growing and lost their hair, says Wan. It took us some time to figure out what was going on.
If the pups were given anti-inflammatory drugs such as aspirin or ibuprofen, the symptoms reversed and their fur started to regrow. These observations suggested that the milk produced by the mutant mice may be the source of the troubles, explained Wan. A closer inspection revealed that the milk of PPAR-deficient mice c
Contact: Gina Kirchweger