Worst asthma symptoms caused by prostaglandin D2
The mechanism behind asthma is under increasing scrutiny. In asthma, environmental antigens trigger immunoglobulin E antibodies, which then activate mast cells. These mast cells release substances that induce inflammation. Experiments with genetically engineered mice now show that one of these inflammation-inducing substances - prostaglandin D2 - is responsible for the worst symptoms of asthma (Science 2000;287:2013-7). When the gene for prostaglandin D2 receptors was removed from asthmatic mice, they did not experience the hyper-reactive airways typical of asthma. Future therapies targeting prostaglandin D2 could mitigate asthma's life-threatening complications.
Pathologic protein gives fruit flies Parkinson's disease
Researchers have created fruit flies with Parkinson's disease - one of the few animal models of the disease, and proof that a mutant protein leads to the neural degeneration in the disease (Nature 2000;404:394-8). They now hope that the flies will show how the protein works, and provide a testing ground for new therapies. The researchers genetically engineered Drosophila melanogaster to express mutated α-synuclein, a protein found in abundance in nerves, whose function is unknown. Two mutations in genes that encode α-synuclein were recently found in families with inherited Parkinson's disease, leading to research into the protein. The fruit flies with mutated proteins have physical signs of Parkinson's disease - progressive loss of dopamine-secreting neurons and intracellular aggregates resembling Lewy bodies - as well as behavioural characteristics. The flies failed a standard vial-climbing test, indicating locomotor defects.