 |
 |
Fri 02 Dec 2005 01:54 PM CST WASHINGTON DC (myDNA News) A newly discovered protein in the human brain may offer hope for future clinical treatments of Parkinson's disease, say researchers at Johns Hopkins' Institute for Cell Engineering in Maryland. The scientists were studying human brain samples to see how mutations of a gene called "LRRK2" affect protein activity. Mutated forms of LRRK2 were previously shown to be linked to Parkinson's in 2004, and the gene is now believed to account for up to 6 percent of genetically inherited cases of the disease. The human body includes many thousands of proteins, each with a specific function. Scientists say the new LRRK2 molecule is a so-called kinase protein, and as such helps to regulate the actions of other proteins in the cell. Specifically, they say, it transfers phosphates onto other proteins. The number of phosphates it transfers, however, depends on the LRRK2 gene. If the gene is in one of its mutated forms known to be linked to Parkinson's disease, the protein shifts into overdrive and more phosphates are transferred. If the gene is in its normal form, fewer phosphates are transferred. The researchers published their findings in the November 15 issue of the Proceedings of the National Academy of Sciences. Ted Dawson, M.D., Ph.D., led the study. "The next step is to prove that LRRK2 overactivity results in the death of brain cells that produce dopamine," says Dawson. Dopamine, a neurotransmitter, is crucial to brain health. Insufficient levels of dopamine can lead to Parkinson's disease, a condition in which patients gradually lose their ability to make voluntary movements. Symptoms of the disorder vary in intensity from person to person, but typically include tremors (shaking), stiffness of the limbs and trunk, slowness of movement, and impaired balance and coordination. There is currently no treatment for Parkinson's disease, but symptoms can be relieved or reduced with medications that mimic dopamine. Dawson's hope is to one day find a way to target the LRRK2 gene and its associated protein with specific medications that control its effects on brain cells. "LRRK2 is an obvious target for drug development," says Dawson. "This discovery is going to have a major impact on the field." According to the National Institute of Neurological Disorders and Stroke, an estimated 500,000 Americans have Parkinson's disease (others put the number at closer to 1.5 million - estimates vary due to the challenges of recognizing the disease). Nearly 50,000 Americans, most over the age of 50, are diagnosed with Parkinson's every year. William Rice, M.D., myDNA's Chief Medical Officer, said that defining the molecular pathways that are associated with the development of Parkinson's disease represents a very great scientific advancement. "However, understanding the disease mechanisms for the other 94 percent of Parkinson's disease patients may remain a significant challenge," he said, "if epigenetic and other factors that modulate gene expression are an important causative factor because these dietary, toxic, or environmental factors, will not be discernable by simply comparing the genome of patients - with, and without the disease." ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn